From 165c6e5b2217f50a4afd8fa34290c34010ebf29c Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Sat, 31 Jul 2021 09:19:46 +0200
Subject: [PATCH 01/24] Fixed crash when server initializes a new world

---
 src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java b/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
index d5c879fc..0866064c 100644
--- a/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
+++ b/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
@@ -105,9 +105,9 @@ public class DataFixerAPI {
 	 */
 	public static boolean fixData(LevelStorageSource.LevelStorageAccess levelStorageAccess, boolean showUI, Consumer<Boolean> onResume){
 		File levelPath = levelStorageAccess.getLevelPath(LevelResource.ROOT).toFile();
-		
+		File levelDat = levelStorageAccess.getLevelPath(LevelResource.LEVEL_DATA_FILE).toFile();
 		boolean newWorld = false;
-		if (!levelPath.exists()) {
+		if (!levelDat.exists()) {
 			BCLib.LOGGER.info("Creating a new World, no fixes needed");
 			newWorld = true;
 		}

From c621b0525e6e2a79edf7237b8152759451c43aff Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Sat, 31 Jul 2021 10:32:09 +0200
Subject: [PATCH 02/24] Hello message initiated on Server

---
 .../bclib/api/dataexchange/DataHandler.java   | 17 ++++-------
 .../{HelloServer.java => HelloClient.java}    | 28 ++++++++++++-------
 2 files changed, 24 insertions(+), 21 deletions(-)
 rename src/main/java/ru/bclib/api/dataexchange/handler/{HelloServer.java => HelloClient.java} (73%)

diff --git a/src/main/java/ru/bclib/api/dataexchange/DataHandler.java b/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
index 0005ced8..f4a360b9 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
@@ -40,24 +40,19 @@ public abstract class DataHandler {
 	
 	@Environment(EnvType.CLIENT)
 	void receiveFromServer(Minecraft client, ClientPacketListener handler, FriendlyByteBuf buf, PacketSender responseSender){
-		deserializeFromIncomingData(buf, responseSender, false);
-		client.execute(() -> runOnClient(client));
+		deserializeFromIncomingData(buf, responseSender, true);
+		client.execute(() -> runOnGameThread(client, null, true));
 	}
 	
 	void receiveFromClient(MinecraftServer server, ServerPlayer player, ServerGamePacketListenerImpl handler, FriendlyByteBuf buf, PacketSender responseSender){
-		deserializeFromIncomingData(buf, responseSender, true);
-		server.execute(() -> runOnServer(server));
+		deserializeFromIncomingData(buf, responseSender, false);
+		server.execute(() -> runOnGameThread(null, server, false));
 	}
 	
-	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient){
+	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean isClient){
 	}
 	
-	@Environment(EnvType.CLIENT)
-	protected void runOnClient(Minecraft client){
-	
-	}
-	
-	protected void runOnServer(MinecraftServer server){
+	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient){
 	
 	}
 	
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
similarity index 73%
rename from src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
rename to src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index 13b2fe02..96c272d9 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -1,7 +1,5 @@
 package ru.bclib.api.dataexchange.handler;
 
-import io.netty.buffer.ByteBufUtil;
-import io.netty.util.CharsetUtil;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
 import net.fabricmc.fabric.api.networking.v1.PacketSender;
@@ -12,7 +10,6 @@ import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
 import ru.bclib.BCLib;
-import ru.bclib.api.WorldDataAPI;
 import ru.bclib.api.dataexchange.DataExchangeAPI;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
@@ -24,11 +21,11 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Optional;
 
-public class HelloServer extends DataHandler {
-	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "hello_server"), HelloServer::new, true);
+public class HelloClient extends DataHandler {
+	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "hello_client"), HelloClient::new, true);
 	
-	public HelloServer() {
-		super(DESCRIPTOR.IDENTIFIER, false);
+	public HelloClient() {
+		super(DESCRIPTOR.IDENTIFIER, true);
 	}
 	
 	public static String getModVersion(String modID){
@@ -60,13 +57,18 @@ public class HelloServer extends DataHandler {
 	}
 	
 	@Override
-	protected void runOnServer(MinecraftServer server) {
+	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
 		String localBclibVersion = getBCLibVersion();
-		BCLib.LOGGER.info("Hello Server received from BCLib. (server="+localBclibVersion+", client="+bclibVersion+")");
+		BCLib.LOGGER.info("Hello Client received from BCLib. (client="+localBclibVersion+", server="+bclibVersion+")");
+		
+		if (DataFixerAPI.getModVersion(localBclibVersion) == DataFixerAPI.getModVersion(bclibVersion)){
+			showBCLibError(client);
+			return;
+		}
 		
 		for (Entry<String, String> e : modVersion.entrySet()){
 			String ver = getModVersion(e.getKey());
-			BCLib.LOGGER.info("    - " + e.getKey() + " (server="+ver+", client="+ver+")");
+			BCLib.LOGGER.info("    - " + e.getKey() + " (client="+ver+", server="+ver+")");
 		}
 	}
 	
@@ -81,4 +83,10 @@ public class HelloServer extends DataHandler {
 			buf.writeInt(DataFixerAPI.getModVersion(getModVersion(modID)));
 		}
 	}
+	
+	@Environment(EnvType.CLIENT)
+	protected void showBCLibError(Minecraft client){
+		BCLib.LOGGER.error("BCLib differs on client and server. Stopping.");
+		client.stop();
+	}
 }

From 114574bff36bfb16ca37ee5b88c5c7849f652c16 Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Sat, 31 Jul 2021 10:32:23 +0200
Subject: [PATCH 03/24] Added class to help with simple GridLayouts

---
 src/main/java/ru/bclib/gui/GridLayout.java    | 122 ++++++++++++++++++
 .../bclib/gui/screens/ConfirmFixScreen.java   |  74 +++--------
 2 files changed, 140 insertions(+), 56 deletions(-)
 create mode 100644 src/main/java/ru/bclib/gui/GridLayout.java

diff --git a/src/main/java/ru/bclib/gui/GridLayout.java b/src/main/java/ru/bclib/gui/GridLayout.java
new file mode 100644
index 00000000..bc4b2976
--- /dev/null
+++ b/src/main/java/ru/bclib/gui/GridLayout.java
@@ -0,0 +1,122 @@
+package ru.bclib.gui;
+
+import com.mojang.blaze3d.vertex.PoseStack;
+import net.minecraft.client.gui.Font;
+import net.minecraft.client.gui.components.Button;
+import net.minecraft.client.gui.components.Button.OnPress;
+import net.minecraft.client.gui.components.MultiLineLabel;
+import net.minecraft.client.gui.screens.Screen;
+import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.TranslatableComponent;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Consumer;
+
+public class GridLayout {
+	class LablePos {
+		final MultiLineLabel label;
+		final int top;
+		
+		LablePos(MultiLineLabel label, int top){
+			this.label = label;
+			this.top = top;
+		}
+	}
+	
+	class ButtonPos {
+		final int height;
+		final int width;
+		final float alpha;
+		final Component component;
+		final Button.OnPress onPress;
+		
+		ButtonPos(float alpha, int width, int height, Component component, OnPress onPress) {
+			this.height = height;
+			this.width = width;
+			this.alpha = alpha;
+			this.component = component;
+			this.onPress = onPress;
+		}
+	}
+	public final int width;
+	@NotNull
+	private final Font font;
+	private final Consumer<Button> addButtonFunction;
+	public final int topStart;
+	private int top;
+	private int currentRowHeight = 0;
+	
+	final private List<LablePos> labels;
+	final private List<ButtonPos> buttons;
+	
+	public GridLayout(int topStart, int width, Font font, Consumer<Button> addButtonFunction){
+		Objects.requireNonNull(font);
+		this.topStart = topStart;
+		top = topStart + 20;
+		this.width = width;
+		this.font = font;
+		this.addButtonFunction = addButtonFunction;
+		labels = new ArrayList<>(4);
+		buttons = new ArrayList<>(8);
+	}
+	
+	public void addMessageRow(MultiLineLabel lb){
+		final int LABEL_MARGIN_BOTTOM = 12;
+		labels.add(new LablePos(lb, top));
+		int promptLines = lb.getLineCount() + 1;
+		int height = promptLines * 9;
+		
+		currentRowHeight = height + LABEL_MARGIN_BOTTOM;;
+	}
+	
+	public void startRow(){
+		this.endRow();
+		top += currentRowHeight;
+		currentRowHeight = 0;
+	}
+	
+	public void endRow(){
+		final int BUTTON_SPACING = 10;
+		int count = buttons.size();
+		int rowWidth = buttons.stream().map(b -> b.width).reduce(0, (p, c) -> p+c) + (count-1) * BUTTON_SPACING;
+		int left = (width-rowWidth)/2;
+		
+		for (ButtonPos bp:buttons){
+			Button customButton = new Button(left, top, bp.width, bp.height, bp.component, bp.onPress);
+			customButton.setAlpha(bp.alpha);
+			addButtonFunction.accept(customButton);
+			
+			left += BUTTON_SPACING + bp.width;
+		};
+		buttons.clear();
+	}
+	public void addButton(int width, int height, Component component, Button.OnPress onPress){
+		addButton(1.0f, width, height, component, onPress);
+	}
+	
+	public void addButton(int height, Component component, Button.OnPress onPress){
+		addButton(1.0f, height, component, onPress);
+	}
+	
+	public void addButton(float alpha, int height, Component component, Button.OnPress onPress){
+		final int BUTTON_PADDING = 12;
+		int width = font.width(component.getVisualOrderText()) + 2*BUTTON_PADDING;
+		addButton(alpha, width, height, component, onPress);
+	}
+	
+	public void addButton(float alpha, int width, int height, Component component, Button.OnPress onPress){
+		final int BUTTON_MARGIN_BOTTOM = 6;
+		
+		currentRowHeight = Math.max(currentRowHeight, height + BUTTON_MARGIN_BOTTOM);
+		buttons.add(new ButtonPos(alpha, width, height, component, onPress));
+	}
+	
+	public void render(PoseStack poseStack){
+		labels.forEach(lp -> {
+			lp.label.renderCentered(poseStack, this.width / 2, lp.top);
+		});
+	}
+}
diff --git a/src/main/java/ru/bclib/gui/screens/ConfirmFixScreen.java b/src/main/java/ru/bclib/gui/screens/ConfirmFixScreen.java
index 54ebbbc5..66fe98bc 100644
--- a/src/main/java/ru/bclib/gui/screens/ConfirmFixScreen.java
+++ b/src/main/java/ru/bclib/gui/screens/ConfirmFixScreen.java
@@ -1,55 +1,19 @@
 package ru.bclib.gui.screens;
 
 
-	import com.mojang.blaze3d.systems.RenderSystem;
 import com.mojang.blaze3d.vertex.PoseStack;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.gui.Font;
-import net.minecraft.client.gui.components.Button;
 import net.minecraft.client.gui.components.MultiLineLabel;
 import net.minecraft.client.gui.screens.BackupConfirmScreen;
 import net.minecraft.client.gui.screens.Screen;
-import net.minecraft.client.renderer.GameRenderer;
 import net.minecraft.network.chat.CommonComponents;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.chat.TranslatableComponent;
 import net.minecraft.resources.ResourceLocation;
-import net.minecraft.util.Mth;
 import org.jetbrains.annotations.Nullable;
 import ru.bclib.BCLib;
-
-import java.util.Objects;
-class ColoredButton extends Button {
-	private final float r;
-	private final float g;
-	private final float b;
-	public ColoredButton(int x, int y, int width, int height, Component component, OnPress onPress, float r, float g, float b) {
-		super(x, y, width, height, component, onPress);
-		this.r = r;
-		this.g = g;
-		this.b = b;
-	}
-	
-	@Override
-	public void renderButton(PoseStack poseStack, int i, int j, float f) {
-		Minecraft minecraft = Minecraft.getInstance();
-		Font font = minecraft.font;
-		RenderSystem.setShader(GameRenderer::getPositionTexShader);
-		RenderSystem.setShaderTexture(0, WIDGETS_LOCATION);
-		RenderSystem.setShaderColor(r, g, b, this.alpha);
-		int k = this.getYImage(this.isHovered());
-		RenderSystem.enableBlend();
-		RenderSystem.defaultBlendFunc();
-		RenderSystem.enableDepthTest();
-		this.blit(poseStack, this.x, this.y, 0, 46 + k * 20, this.width / 2, this.height);
-		this.blit(poseStack, this.x + this.width / 2, this.y, 200 - this.width / 2, 46 + k * 20, this.width / 2, this.height);
-		this.renderBg(poseStack, minecraft, i, j);
-		int l = this.active ? 16777215 : 10526880;
-		drawCenteredString(poseStack, font, this.getMessage(), this.x + this.width / 2, this.y + (this.height - 8) / 2, l | Mth.ceil(this.alpha * 255.0F) << 24);
-	}
-}
+import ru.bclib.gui.GridLayout;
 
 @Environment(EnvType.CLIENT)
 public class ConfirmFixScreen extends Screen {
@@ -61,54 +25,52 @@ public class ConfirmFixScreen extends Screen {
 	private final Component description;
 	private MultiLineLabel message;
 	protected int id;
+	private GridLayout grid = null;
 	
 	public ConfirmFixScreen(@Nullable Screen screen, BackupConfirmScreen.Listener listener) {
 		super(new TranslatableComponent("bclib.datafixer.backupWarning.title"));
 		this.message = MultiLineLabel.EMPTY;
 		this.lastScreen = screen;
 		this.listener = listener;
+		
 		this.description = new TranslatableComponent("bclib.datafixer.backupWarning.message");
 	}
 	
 	protected void init() {
 		super.init();
-		this.message = MultiLineLabel.create(this.font, this.description, this.width - 50);
-		int promptLines = this.message.getLineCount() + 1;
-		Objects.requireNonNull(this.font);
-		int height = promptLines * 9;
+		this.grid = new GridLayout(30, this.width, this.font, this::addRenderableWidget);
+		
 		final int BUTTON_WIDTH = 150;
 		final int BUTTON_SPACE = 10;
 		final int BUTTON_HEIGHT = 20;
 		
-		Button customButton = new Button((this.width -BUTTON_WIDTH)/2, 100 + height, BUTTON_WIDTH, BUTTON_HEIGHT, new TranslatableComponent("bclib.datafixer.backupWarning.backup"), (button) -> {
+		grid.addMessageRow(MultiLineLabel.create(this.font, this.description, this.width - 50));
+		
+		grid.startRow();
+		grid.addButton( BUTTON_HEIGHT, new TranslatableComponent("bclib.datafixer.backupWarning.backup"), (button) -> {
 			this.listener.proceed(true, true);
 		});
-		this.addRenderableWidget(customButton);
 		
-		
-		customButton = new Button((this.width - 2*BUTTON_WIDTH - BUTTON_SPACE)/ 2  , 124 + height, BUTTON_WIDTH, BUTTON_HEIGHT, CommonComponents.GUI_CANCEL, (button) -> {
+		grid.startRow();
+		grid.addButton( BUTTON_HEIGHT, CommonComponents.GUI_CANCEL, (button) -> {
 			this.minecraft.setScreen(this.lastScreen);
 		});
-		this.addRenderableWidget(customButton);
-		
-		customButton = new Button((this.width - 2*BUTTON_WIDTH - BUTTON_SPACE)/ 2 + BUTTON_WIDTH+BUTTON_SPACE, 124 + height, BUTTON_WIDTH, BUTTON_HEIGHT, new TranslatableComponent("bclib.datafixer.backupWarning.continue"), (button) -> {
+		grid.addButton(0.5f, BUTTON_HEIGHT, new TranslatableComponent("bclib.datafixer.backupWarning.continue"), (button) -> {
 			this.listener.proceed(false, true);
 		});
-		customButton.setAlpha(0.5f);
-		this.addRenderableWidget(customButton);
 		
-		
-		customButton = new Button((this.width - BUTTON_WIDTH)/ 2, 148 + height, BUTTON_WIDTH, BUTTON_HEIGHT, new TranslatableComponent("bclib.datafixer.backupWarning.nofixes"), (button) -> {
+		grid.startRow();
+		grid.addButton(0.5f, BUTTON_HEIGHT, new TranslatableComponent("bclib.datafixer.backupWarning.nofixes"), (button) -> {
 			this.listener.proceed(false, false);
 		});
-		customButton.setAlpha(0.5f);
-		this.addRenderableWidget(customButton);
+		
+		grid.endRow();
 	}
 	
 	public void render(PoseStack poseStack, int i, int j, float f) {
 		this.renderBackground(poseStack);
-		drawCenteredString(poseStack, this.font, this.title, this.width / 2, 50, 16777215);
-		this.message.renderCentered(poseStack, this.width / 2, 70);
+		drawCenteredString(poseStack, this.font, this.title, grid.width / 2, grid.topStart, 16777215);
+		if (grid!=null) grid.render(poseStack);
 		super.render(poseStack, i, j, f);
 	}
 	

From 46a5603ff7a1a439ba72fab74c9e3951dbf4717c Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Sat, 31 Jul 2021 10:32:48 +0200
Subject: [PATCH 04/24] fixed import

---
 src/main/java/ru/bclib/BCLib.java | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/main/java/ru/bclib/BCLib.java b/src/main/java/ru/bclib/BCLib.java
index 15f4b841..da25b58f 100644
--- a/src/main/java/ru/bclib/BCLib.java
+++ b/src/main/java/ru/bclib/BCLib.java
@@ -7,7 +7,7 @@ import net.minecraft.resources.ResourceLocation;
 import ru.bclib.api.TagAPI;
 import ru.bclib.api.WorldDataAPI;
 import ru.bclib.api.dataexchange.DataExchangeAPI;
-import ru.bclib.api.dataexchange.handler.HelloServer;
+import ru.bclib.api.dataexchange.handler.HelloClient;
 import ru.bclib.config.Configs;
 import ru.bclib.recipes.CraftingRecipes;
 import ru.bclib.registry.BaseBlockEntities;
@@ -28,7 +28,8 @@ public class BCLib implements ModInitializer {
 		CraftingRecipes.init();
 		WorldDataAPI.registerModCache(MOD_ID);
 		Configs.save();
-		DataExchangeAPI.registerDescriptor(HelloServer.DESCRIPTOR);
+		
+		DataExchangeAPI.registerDescriptor(HelloClient.DESCRIPTOR);
 	}
 	
 	public static boolean isDevEnvironment() {

From 4fc9c0620490fa50114c4a3c7e2d20a4bd63632c Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Sat, 31 Jul 2021 11:29:13 +0200
Subject: [PATCH 05/24] Prepared BCLib Version warning screen

---
 .../api/dataexchange/handler/HelloClient.java | 21 ++++-
 .../ru/bclib/api/datafixer/DataFixerAPI.java  |  4 -
 src/main/java/ru/bclib/gui/GridLayout.java    | 90 +++++++++++++------
 src/main/java/ru/bclib/gui/GridScreen.java    | 34 +++++++
 .../bclib/gui/screens/ConfirmFixScreen.java   | 30 ++-----
 .../gui/screens/WarnBCLibVersionMismatch.java | 46 ++++++++++
 .../resources/assets/bclib/lang/en_us.json    |  4 +-
 7 files changed, 171 insertions(+), 58 deletions(-)
 create mode 100644 src/main/java/ru/bclib/gui/GridScreen.java
 create mode 100644 src/main/java/ru/bclib/gui/screens/WarnBCLibVersionMismatch.java

diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index 96c272d9..ef35015d 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -6,6 +6,8 @@ import net.fabricmc.fabric.api.networking.v1.PacketSender;
 import net.fabricmc.loader.api.FabricLoader;
 import net.fabricmc.loader.api.ModContainer;
 import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.screens.Screen;
+import net.minecraft.client.gui.screens.worldselection.EditWorldScreen;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
@@ -14,12 +16,15 @@ import ru.bclib.api.dataexchange.DataExchangeAPI;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
 import ru.bclib.api.datafixer.DataFixerAPI;
+import ru.bclib.gui.screens.ConfirmFixScreen;
+import ru.bclib.gui.screens.WarnBCLibVersionMismatch;
 
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Optional;
+import java.util.function.Consumer;
 
 public class HelloClient extends DataHandler {
 	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "hello_client"), HelloClient::new, true);
@@ -86,7 +91,19 @@ public class HelloClient extends DataHandler {
 	
 	@Environment(EnvType.CLIENT)
 	protected void showBCLibError(Minecraft client){
-		BCLib.LOGGER.error("BCLib differs on client and server. Stopping.");
-		client.stop();
+		client.pauseGame(false);
+		BCLib.LOGGER.error("BCLib differs on client and server.");
+		client.setScreen(new WarnBCLibVersionMismatch((download) -> {
+			Minecraft.getInstance().setScreen((Screen)null);
+			if (download){
+				requestDownloads((hadErrors)->{
+					client.stop();
+				});
+			}
+		}));
+	}
+	
+	private void requestDownloads(Consumer<Boolean> whenFinished){
+		BCLib.LOGGER.warning("Starting download of BCLib");
 	}
 }
diff --git a/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java b/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
index 0866064c..dfdec8d7 100644
--- a/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
+++ b/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
@@ -227,9 +227,6 @@ public class DataFixerAPI {
 	
 	@Environment(EnvType.CLIENT)
 	static void showBackupWarning(String levelID, Consumer<Boolean> whenFinished){
-		TranslatableComponent promptText = new TranslatableComponent("bclib.datafixer.backupWarning.prompt");
-		TranslatableComponent buttonTitle = new TranslatableComponent("bclib.datafixer.backupWarning.button");
-		
 		Minecraft.getInstance().setScreen(new ConfirmFixScreen((Screen) null, (createBackup, applyFixes) -> {
 			if (createBackup) {
 				EditWorldScreen.makeBackupAndShowToast(Minecraft.getInstance().getLevelSource(), levelID);
@@ -238,7 +235,6 @@ public class DataFixerAPI {
 			Minecraft.getInstance().setScreen((Screen)null);
 			whenFinished.accept(applyFixes);
 		}));
-		
 	}
 
 	private static void runDataFixes(File dir, MigrationProfile profile, ProgressListener progress) {
diff --git a/src/main/java/ru/bclib/gui/GridLayout.java b/src/main/java/ru/bclib/gui/GridLayout.java
index bc4b2976..c8b3005b 100644
--- a/src/main/java/ru/bclib/gui/GridLayout.java
+++ b/src/main/java/ru/bclib/gui/GridLayout.java
@@ -5,9 +5,7 @@ import net.minecraft.client.gui.Font;
 import net.minecraft.client.gui.components.Button;
 import net.minecraft.client.gui.components.Button.OnPress;
 import net.minecraft.client.gui.components.MultiLineLabel;
-import net.minecraft.client.gui.screens.Screen;
 import net.minecraft.network.chat.Component;
-import net.minecraft.network.chat.TranslatableComponent;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
@@ -27,72 +25,107 @@ public class GridLayout {
 	}
 	
 	class ButtonPos {
+		final int top;
 		final int height;
 		final int width;
 		final float alpha;
 		final Component component;
 		final Button.OnPress onPress;
 		
-		ButtonPos(float alpha, int width, int height, Component component, OnPress onPress) {
+		ButtonPos(float alpha, int top, int width, int height, Component component, OnPress onPress) {
 			this.height = height;
 			this.width = width;
+			this.top = top;
 			this.alpha = alpha;
 			this.component = component;
 			this.onPress = onPress;
 		}
 	}
 	public final int width;
+	public final int height;
 	@NotNull
 	private final Font font;
 	private final Consumer<Button> addButtonFunction;
-	public final int topStart;
+	private final int topStart;
+	private int topOffset;
 	private int top;
 	private int currentRowHeight = 0;
+	private int currentRowMargin = 6;
+	private int lastRowMargin = 0;
 	
 	final private List<LablePos> labels;
-	final private List<ButtonPos> buttons;
+	final private List<List<ButtonPos>> buttons;
+	private List<ButtonPos> currentButtonRow;
 	
-	public GridLayout(int topStart, int width, Font font, Consumer<Button> addButtonFunction){
+	public GridLayout(int topStart, int width, int height, Font font, Consumer<Button> addButtonFunction){
 		Objects.requireNonNull(font);
 		this.topStart = topStart;
 		top = topStart + 20;
+		this.topOffset = 0;
 		this.width = width;
+		this.height = height;
 		this.font = font;
 		this.addButtonFunction = addButtonFunction;
 		labels = new ArrayList<>(4);
-		buttons = new ArrayList<>(8);
+		buttons = new ArrayList<>(4);
+	}
+	
+	public int getTopStart(){
+		return topStart + topOffset;
+	}
+	
+	public void addMessageRow(Component text, int padding){
+		addMessageRow(MultiLineLabel.create(this.font, text, this.width - 2*padding));
 	}
 	
 	public void addMessageRow(MultiLineLabel lb){
-		final int LABEL_MARGIN_BOTTOM = 12;
 		labels.add(new LablePos(lb, top));
 		int promptLines = lb.getLineCount() + 1;
 		int height = promptLines * 9;
 		
-		currentRowHeight = height + LABEL_MARGIN_BOTTOM;;
+		currentRowMargin = 12;
+		currentRowHeight = height;
 	}
 	
 	public void startRow(){
 		this.endRow();
-		top += currentRowHeight;
-		currentRowHeight = 0;
+		this.currentButtonRow = new ArrayList<>(8);
+		this.buttons.add(this.currentButtonRow);
+		
 	}
 	
 	public void endRow(){
-		final int BUTTON_SPACING = 10;
-		int count = buttons.size();
-		int rowWidth = buttons.stream().map(b -> b.width).reduce(0, (p, c) -> p+c) + (count-1) * BUTTON_SPACING;
-		int left = (width-rowWidth)/2;
-		
-		for (ButtonPos bp:buttons){
-			Button customButton = new Button(left, top, bp.width, bp.height, bp.component, bp.onPress);
-			customButton.setAlpha(bp.alpha);
-			addButtonFunction.accept(customButton);
-			
-			left += BUTTON_SPACING + bp.width;
-		};
-		buttons.clear();
+		lastRowMargin = currentRowMargin;
+		top += currentRowHeight + currentRowMargin;
+		currentRowHeight = 0;
+		currentRowMargin = 0;
 	}
+	
+	public void recenterVertically(){
+		int hg = (top - lastRowMargin) - topStart;
+		int targetTop = (height - hg)/2;
+		topOffset = targetTop - topStart;
+	}
+	
+	void finalizeLayout(){
+		final int BUTTON_SPACING = 10;
+		for (List<ButtonPos> row : this.buttons) {
+			int count = row.size();
+			int rowWidth = row.stream()
+										   .map(b -> b.width)
+										   .reduce(0, (p, c) -> p + c) + (count - 1) * BUTTON_SPACING;
+			int left = (width - rowWidth) / 2;
+			
+			for (ButtonPos bp : row) {
+				Button customButton = new Button(left, bp.top+topOffset, bp.width, bp.height, bp.component, bp.onPress);
+				customButton.setAlpha(bp.alpha);
+				addButtonFunction.accept(customButton);
+				
+				left += BUTTON_SPACING + bp.width;
+			}
+		}
+	}
+	
 	public void addButton(int width, int height, Component component, Button.OnPress onPress){
 		addButton(1.0f, width, height, component, onPress);
 	}
@@ -108,15 +141,14 @@ public class GridLayout {
 	}
 	
 	public void addButton(float alpha, int width, int height, Component component, Button.OnPress onPress){
-		final int BUTTON_MARGIN_BOTTOM = 6;
-		
-		currentRowHeight = Math.max(currentRowHeight, height + BUTTON_MARGIN_BOTTOM);
-		buttons.add(new ButtonPos(alpha, width, height, component, onPress));
+		currentRowHeight = Math.max(currentRowHeight, height);
+		currentRowMargin = 6;
+		currentButtonRow.add(new ButtonPos(alpha, top, width, height, component, onPress));
 	}
 	
 	public void render(PoseStack poseStack){
 		labels.forEach(lp -> {
-			lp.label.renderCentered(poseStack, this.width / 2, lp.top);
+			lp.label.renderCentered(poseStack, this.width / 2, lp.top + topOffset);
 		});
 	}
 }
diff --git a/src/main/java/ru/bclib/gui/GridScreen.java b/src/main/java/ru/bclib/gui/GridScreen.java
new file mode 100644
index 00000000..fb93cd7d
--- /dev/null
+++ b/src/main/java/ru/bclib/gui/GridScreen.java
@@ -0,0 +1,34 @@
+package ru.bclib.gui;
+
+import com.mojang.blaze3d.vertex.PoseStack;
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
+import net.minecraft.client.gui.screens.Screen;
+import net.minecraft.network.chat.Component;
+
+@Environment(EnvType.CLIENT)
+public abstract class GridScreen extends Screen {
+	protected GridLayout grid = null;
+	public final int topStart;
+	
+	public GridScreen(int topStart, Component title) {
+		super(title);
+		this.topStart = topStart;
+	}
+	
+	final protected void init() {
+		super.init();
+		this.grid = new GridLayout(topStart, this.width, this.height, this.font, this::addRenderableWidget);
+		initLayout();
+		grid.finalizeLayout();
+	}
+	
+	protected abstract void initLayout();
+	
+	public void render(PoseStack poseStack, int i, int j, float f) {
+		this.renderBackground(poseStack);
+		drawCenteredString(poseStack, this.font, this.title, grid.width / 2, grid.getTopStart(), 16777215);
+		if (grid!=null) grid.render(poseStack);
+		super.render(poseStack, i, j, f);
+	}
+}
diff --git a/src/main/java/ru/bclib/gui/screens/ConfirmFixScreen.java b/src/main/java/ru/bclib/gui/screens/ConfirmFixScreen.java
index 66fe98bc..8e6d44f7 100644
--- a/src/main/java/ru/bclib/gui/screens/ConfirmFixScreen.java
+++ b/src/main/java/ru/bclib/gui/screens/ConfirmFixScreen.java
@@ -14,37 +14,30 @@ import net.minecraft.resources.ResourceLocation;
 import org.jetbrains.annotations.Nullable;
 import ru.bclib.BCLib;
 import ru.bclib.gui.GridLayout;
+import ru.bclib.gui.GridScreen;
 
 @Environment(EnvType.CLIENT)
-public class ConfirmFixScreen extends Screen {
+public class ConfirmFixScreen extends GridScreen {
 	static final ResourceLocation BCLIB_LOGO_LOCATION = new ResourceLocation(BCLib.MOD_ID,
 		"icon.png");
 	@Nullable
 	private final Screen lastScreen;
-	protected final BackupConfirmScreen.Listener listener;
+	protected final ConfirmFixScreen.Listener listener;
 	private final Component description;
-	private MultiLineLabel message;
 	protected int id;
-	private GridLayout grid = null;
 	
-	public ConfirmFixScreen(@Nullable Screen screen, BackupConfirmScreen.Listener listener) {
-		super(new TranslatableComponent("bclib.datafixer.backupWarning.title"));
-		this.message = MultiLineLabel.EMPTY;
+	public ConfirmFixScreen(@Nullable Screen screen, ConfirmFixScreen.Listener listener) {
+		super(30, new TranslatableComponent("bclib.datafixer.backupWarning.title"));
 		this.lastScreen = screen;
 		this.listener = listener;
 		
 		this.description = new TranslatableComponent("bclib.datafixer.backupWarning.message");
 	}
 	
-	protected void init() {
-		super.init();
-		this.grid = new GridLayout(30, this.width, this.font, this::addRenderableWidget);
-		
-		final int BUTTON_WIDTH = 150;
-		final int BUTTON_SPACE = 10;
+	protected void initLayout() {
 		final int BUTTON_HEIGHT = 20;
 		
-		grid.addMessageRow(MultiLineLabel.create(this.font, this.description, this.width - 50));
+		grid.addMessageRow(this.description, 25);
 		
 		grid.startRow();
 		grid.addButton( BUTTON_HEIGHT, new TranslatableComponent("bclib.datafixer.backupWarning.backup"), (button) -> {
@@ -67,13 +60,6 @@ public class ConfirmFixScreen extends Screen {
 		grid.endRow();
 	}
 	
-	public void render(PoseStack poseStack, int i, int j, float f) {
-		this.renderBackground(poseStack);
-		drawCenteredString(poseStack, this.font, this.title, grid.width / 2, grid.topStart, 16777215);
-		if (grid!=null) grid.render(poseStack);
-		super.render(poseStack, i, j, f);
-	}
-	
 	public boolean shouldCloseOnEsc() {
 		return false;
 	}
@@ -89,6 +75,6 @@ public class ConfirmFixScreen extends Screen {
 	
 	@Environment(EnvType.CLIENT)
 	public interface Listener {
-		void proceed(boolean bl, boolean bl2);
+		void proceed(boolean createBackup, boolean applyPatches);
 	}
 }
diff --git a/src/main/java/ru/bclib/gui/screens/WarnBCLibVersionMismatch.java b/src/main/java/ru/bclib/gui/screens/WarnBCLibVersionMismatch.java
new file mode 100644
index 00000000..24a2ec0d
--- /dev/null
+++ b/src/main/java/ru/bclib/gui/screens/WarnBCLibVersionMismatch.java
@@ -0,0 +1,46 @@
+package ru.bclib.gui.screens;
+
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
+import net.minecraft.network.chat.CommonComponents;
+import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.TranslatableComponent;
+import ru.bclib.gui.GridScreen;
+
+@Environment(EnvType.CLIENT)
+public class WarnBCLibVersionMismatch extends GridScreen {
+	private final Component description;
+	private final Listener listener;
+	public WarnBCLibVersionMismatch(Listener listener) {
+		super(30, new TranslatableComponent("bclib.datafixer.bclibmissmatch.title"));
+		
+		this.description = new TranslatableComponent("bclib.datafixer.bclibmissmatch.message");
+		this.listener = listener;
+	}
+	
+	protected void initLayout() {
+		final int BUTTON_HEIGHT = 20;
+		
+		grid.addMessageRow(this.description, 25);
+		
+		grid.startRow();
+		grid.addButton( BUTTON_HEIGHT, CommonComponents.GUI_NO, (button) -> {
+			listener.proceed(false);
+		});
+		grid.addButton( BUTTON_HEIGHT, CommonComponents.GUI_YES, (button) -> {
+			listener.proceed(true);
+		});
+		
+		grid.endRow();
+		grid.recenterVertically();
+	}
+	
+	public boolean shouldCloseOnEsc() {
+		return false;
+	}
+	
+	@Environment(EnvType.CLIENT)
+	public interface Listener {
+		void proceed(boolean download);
+	}
+}
diff --git a/src/main/resources/assets/bclib/lang/en_us.json b/src/main/resources/assets/bclib/lang/en_us.json
index 6df95514..c4c8b0ec 100644
--- a/src/main/resources/assets/bclib/lang/en_us.json
+++ b/src/main/resources/assets/bclib/lang/en_us.json
@@ -4,5 +4,7 @@
 	"bclib.datafixer.backupWarning.message": "The Guardian detected, that the internals of the following Mods did change since this world was last played.\n\nWe can automatically change the world for you. If you continue without applying the changes the world may not load correct. Before you continue, you should create a Backup.",
 	"bclib.datafixer.backupWarning.backup": "Create Backup and Continue",
 	"bclib.datafixer.backupWarning.nofixes": "Continue Without Fixes",
-	"bclib.datafixer.backupWarning.continue": "Continue Without Backup"
+	"bclib.datafixer.backupWarning.continue": "Continue Without Backup",
+	"bclib.datafixer.bclibmissmatch.title": "Version Mismatch",
+	"bclib.datafixer.bclibmissmatch.message": "The Version of BCLib on the server and this client do not match. This will cause problems when playing.\n\nDo you want to automatically download the BCLib-Version from the server. You will need to delete the old version from your Mods Directory and restart the game."
 }
\ No newline at end of file

From 7bfe0b01cdde01b27bf1f40ac30665b31b1d00b0 Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Sat, 31 Jul 2021 13:51:39 +0200
Subject: [PATCH 06/24] Ability to send data when player first enters the level

---
 .../api/dataexchange/DataExchangeAPI.java     | 27 +++++++++++++-
 .../bclib/api/dataexchange/DataHandler.java   | 10 +++--
 .../dataexchange/DataHandlerDescriptor.java   | 10 +++--
 .../api/dataexchange/handler/HelloClient.java |  6 +--
 .../api/dataexchange/handler/HelloServer.java | 37 +++++++++++++++++++
 .../bclib/mixin/client/ClientLevelMixin.java  |  2 +
 6 files changed, 80 insertions(+), 12 deletions(-)
 create mode 100644 src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
 create mode 100644 src/main/java/ru/bclib/mixin/client/ClientLevelMixin.java

diff --git a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
index 73cac348..f354928d 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
@@ -3,8 +3,10 @@ package ru.bclib.api.dataexchange;
 import com.google.common.collect.Lists;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
+import net.fabricmc.fabric.api.client.networking.v1.ClientLoginConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
+import net.minecraft.client.Minecraft;
 import net.minecraft.network.FriendlyByteBuf;
 
 import java.util.HashSet;
@@ -34,7 +36,12 @@ public class DataExchangeAPI {
 	private void initClientside(){
 		if (client!=null) return;
 		client = new ConnectorClientside(this);
-		
+		ClientLoginConnectionEvents.INIT.register((a, b) ->{
+			System.out.println("INIT");
+		});
+		ClientLoginConnectionEvents.QUERY_START.register((a, b) ->{
+			System.out.println("INIT");
+		});
 		ClientPlayConnectionEvents.INIT.register(client::onPlayInit);
 		ClientPlayConnectionEvents.JOIN.register(client::onPlayReady);
 		ClientPlayConnectionEvents.DISCONNECT.register(client::onPlayDisconnect);
@@ -117,5 +124,21 @@ public class DataExchangeAPI {
 		}
 	}
 	
-	
+	/**
+	 * Automatically called before the player enters the world.
+	 * <p>
+	 * This will send all {@link DataHandler}-Objects that have {@link DataHandlerDescriptor#sendBeforeEnter} set to*
+	 * {@Code true},
+	 */
+	@Environment(EnvType.CLIENT)
+	public static void sendOnEnter(){
+		getInstance().descriptors.forEach((desc)-> {
+			if (desc.sendBeforeEnter){
+				DataHandler h = desc.JOIN_INSTANCE.get();
+				if (!h.getOriginatesOnServer()) {
+					getInstance().client.sendToServer(h);
+				}
+			}
+		});
+	}
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/DataHandler.java b/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
index f4a360b9..fb11bd25 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
@@ -1,7 +1,5 @@
 package ru.bclib.api.dataexchange;
 
-import io.netty.buffer.ByteBufUtil;
-import io.netty.util.CharsetUtil;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking;
@@ -44,7 +42,9 @@ public abstract class DataHandler {
 		client.execute(() -> runOnGameThread(client, null, true));
 	}
 	
+	private ServerPlayer lastMessageSender;
 	void receiveFromClient(MinecraftServer server, ServerPlayer player, ServerGamePacketListenerImpl handler, FriendlyByteBuf buf, PacketSender responseSender){
+		lastMessageSender = player;
 		deserializeFromIncomingData(buf, responseSender, false);
 		server.execute(() -> runOnGameThread(null, server, false));
 	}
@@ -53,11 +53,15 @@ public abstract class DataHandler {
 	}
 	
 	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient){
-	
 	}
 	
 	protected void serializeData(FriendlyByteBuf buf) {
+	}
 	
+	final protected boolean reply(DataHandler message, MinecraftServer server){
+		if (lastMessageSender==null) return false;
+		message.sendToClient(server, lastMessageSender);
+		return true;
 	}
 	
 	void sendToClient(MinecraftServer server){
diff --git a/src/main/java/ru/bclib/api/dataexchange/DataHandlerDescriptor.java b/src/main/java/ru/bclib/api/dataexchange/DataHandlerDescriptor.java
index 585a3725..99017fe4 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataHandlerDescriptor.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataHandlerDescriptor.java
@@ -6,21 +6,23 @@ import java.util.function.Supplier;
 
 public class DataHandlerDescriptor {
 	public DataHandlerDescriptor(ResourceLocation identifier, Supplier<DataHandler> instancer){
-		this(identifier, instancer, instancer, false);
+		this(identifier, instancer, instancer, false, false);
 	}
 	
-	public DataHandlerDescriptor(ResourceLocation identifier, Supplier<DataHandler> instancer, boolean sendOnJoin){
-		this(identifier, instancer, instancer, sendOnJoin);
+	public DataHandlerDescriptor(ResourceLocation identifier, Supplier<DataHandler> instancer, boolean sendOnJoin, boolean sendBeforeEnter){
+		this(identifier, instancer, instancer, sendOnJoin, sendBeforeEnter);
 	}
-	public DataHandlerDescriptor(ResourceLocation identifier, Supplier<DataHandler> receiv_instancer, Supplier<DataHandler> join_instancer, boolean sendOnJoin){
+	public DataHandlerDescriptor(ResourceLocation identifier, Supplier<DataHandler> receiv_instancer, Supplier<DataHandler> join_instancer, boolean sendOnJoin, boolean sendBeforeEnter){
 		this.INSTANCE = receiv_instancer;
 		this.JOIN_INSTANCE = join_instancer;
 		this.IDENTIFIER = identifier;
 		
 		this.sendOnJoin = sendOnJoin;
+		this.sendBeforeEnter = sendBeforeEnter;
 	}
 	
 	public final boolean sendOnJoin;
+	public final boolean sendBeforeEnter;
 	public final ResourceLocation IDENTIFIER;
 	public final Supplier<DataHandler> INSTANCE;
 	public final Supplier<DataHandler> JOIN_INSTANCE;
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index ef35015d..cfcf17c8 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -27,7 +27,7 @@ import java.util.Optional;
 import java.util.function.Consumer;
 
 public class HelloClient extends DataHandler {
-	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "hello_client"), HelloClient::new, true);
+	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "hello_client"), HelloClient::new, false, false);
 	
 	public HelloClient() {
 		super(DESCRIPTOR.IDENTIFIER, true);
@@ -42,7 +42,7 @@ public class HelloClient extends DataHandler {
 		return "0.0.0";
 	}
 	
-	protected static String getBCLibVersion(){
+	static String getBCLibVersion(){
 		return getModVersion(BCLib.MOD_ID);
 	}
 	
@@ -64,7 +64,7 @@ public class HelloClient extends DataHandler {
 	@Override
 	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
 		String localBclibVersion = getBCLibVersion();
-		BCLib.LOGGER.info("Hello Client received from BCLib. (client="+localBclibVersion+", server="+bclibVersion+")");
+		BCLib.LOGGER.info("Received Hello from Server. (client="+localBclibVersion+", server="+bclibVersion+")");
 		
 		if (DataFixerAPI.getModVersion(localBclibVersion) == DataFixerAPI.getModVersion(bclibVersion)){
 			showBCLibError(client);
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
new file mode 100644
index 00000000..13d1ce63
--- /dev/null
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
@@ -0,0 +1,37 @@
+package ru.bclib.api.dataexchange.handler;
+
+import net.fabricmc.fabric.api.networking.v1.PacketSender;
+import net.minecraft.client.Minecraft;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MinecraftServer;
+import ru.bclib.BCLib;
+import ru.bclib.api.dataexchange.DataHandler;
+import ru.bclib.api.dataexchange.DataHandlerDescriptor;
+import ru.bclib.api.datafixer.DataFixerAPI;
+
+public class HelloServer extends DataHandler {
+	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "hello_server"), HelloServer::new, false, true);
+	
+	protected String bclibVersion ="0.0.0";
+	public HelloServer() {
+		super(DESCRIPTOR.IDENTIFIER, false);
+	}
+	
+	@Override
+	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
+		bclibVersion = DataFixerAPI.getModVersion(buf.readInt());
+	}
+	
+	@Override
+	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
+		String localBclibVersion = HelloClient.getBCLibVersion();
+		BCLib.LOGGER.info("Received Hello from Server. (server="+localBclibVersion+", client="+bclibVersion+")");
+		reply(new HelloClient(), server);
+	}
+	
+	@Override
+	protected void serializeData(FriendlyByteBuf buf) {
+		buf.writeInt(DataFixerAPI.getModVersion(HelloClient.getBCLibVersion()));
+	}
+}
diff --git a/src/main/java/ru/bclib/mixin/client/ClientLevelMixin.java b/src/main/java/ru/bclib/mixin/client/ClientLevelMixin.java
new file mode 100644
index 00000000..26061eda
--- /dev/null
+++ b/src/main/java/ru/bclib/mixin/client/ClientLevelMixin.java
@@ -0,0 +1,2 @@
+package ru.bclib.mixin.client;public class ClientLevelMixin {
+}

From 70cfdf0dd829c0407a665ac14a68bb9025fcd6a6 Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Sat, 31 Jul 2021 14:04:14 +0200
Subject: [PATCH 07/24] Display DataExchange Dialog

---
 src/main/java/ru/bclib/BCLib.java             |  2 ++
 .../api/dataexchange/handler/HelloClient.java |  1 -
 .../client/ClientboundLoginPacketMixin.java   | 20 +++++++++++++++++++
 .../java/ru/bclib/mixin/client/GameMixin.java | 18 +++++++++++++++++
 .../ru/bclib/mixin/client/MinecraftMixin.java |  5 +++++
 src/main/resources/bclib.mixins.client.json   |  1 +
 6 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/ru/bclib/mixin/client/ClientboundLoginPacketMixin.java
 create mode 100644 src/main/java/ru/bclib/mixin/client/GameMixin.java

diff --git a/src/main/java/ru/bclib/BCLib.java b/src/main/java/ru/bclib/BCLib.java
index da25b58f..7de687de 100644
--- a/src/main/java/ru/bclib/BCLib.java
+++ b/src/main/java/ru/bclib/BCLib.java
@@ -8,6 +8,7 @@ import ru.bclib.api.TagAPI;
 import ru.bclib.api.WorldDataAPI;
 import ru.bclib.api.dataexchange.DataExchangeAPI;
 import ru.bclib.api.dataexchange.handler.HelloClient;
+import ru.bclib.api.dataexchange.handler.HelloServer;
 import ru.bclib.config.Configs;
 import ru.bclib.recipes.CraftingRecipes;
 import ru.bclib.registry.BaseBlockEntities;
@@ -30,6 +31,7 @@ public class BCLib implements ModInitializer {
 		Configs.save();
 		
 		DataExchangeAPI.registerDescriptor(HelloClient.DESCRIPTOR);
+		DataExchangeAPI.registerDescriptor(HelloServer.DESCRIPTOR);
 	}
 	
 	public static boolean isDevEnvironment() {
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index cfcf17c8..6bdccd89 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -91,7 +91,6 @@ public class HelloClient extends DataHandler {
 	
 	@Environment(EnvType.CLIENT)
 	protected void showBCLibError(Minecraft client){
-		client.pauseGame(false);
 		BCLib.LOGGER.error("BCLib differs on client and server.");
 		client.setScreen(new WarnBCLibVersionMismatch((download) -> {
 			Minecraft.getInstance().setScreen((Screen)null);
diff --git a/src/main/java/ru/bclib/mixin/client/ClientboundLoginPacketMixin.java b/src/main/java/ru/bclib/mixin/client/ClientboundLoginPacketMixin.java
new file mode 100644
index 00000000..b25550cb
--- /dev/null
+++ b/src/main/java/ru/bclib/mixin/client/ClientboundLoginPacketMixin.java
@@ -0,0 +1,20 @@
+package ru.bclib.mixin.client;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.network.protocol.game.ClientGamePacketListener;
+import net.minecraft.network.protocol.game.ClientboundLoginPacket;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+import ru.bclib.api.dataexchange.DataExchangeAPI;
+
+@Mixin(ClientboundLoginPacket.class)
+public abstract class ClientboundLoginPacketMixin {
+	@Inject(method = "handle", cancellable = true, at=@At("HEAD"))
+	public void bclib_handle(ClientGamePacketListener clientGamePacketListener, CallbackInfo ci){
+		//cLevel.setBCLibDidSendHello();
+//		DataExchangeAPI.sendOnEnter();
+//		ci.cancel();
+	}
+}
diff --git a/src/main/java/ru/bclib/mixin/client/GameMixin.java b/src/main/java/ru/bclib/mixin/client/GameMixin.java
new file mode 100644
index 00000000..0753dd73
--- /dev/null
+++ b/src/main/java/ru/bclib/mixin/client/GameMixin.java
@@ -0,0 +1,18 @@
+package ru.bclib.mixin.client;
+
+import net.minecraft.client.Game;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+import ru.bclib.api.dataexchange.DataExchangeAPI;
+import ru.bclib.api.dataexchange.handler.HelloServer;
+
+@Mixin(Game.class)
+public class GameMixin {
+	
+	@Inject(method="onStartGameSession", at=@At("TAIL"))
+	public void bcliv_onStart(CallbackInfo ci){
+		DataExchangeAPI.send(new HelloServer());
+	}
+}
diff --git a/src/main/java/ru/bclib/mixin/client/MinecraftMixin.java b/src/main/java/ru/bclib/mixin/client/MinecraftMixin.java
index 7cfd889a..3401de2a 100644
--- a/src/main/java/ru/bclib/mixin/client/MinecraftMixin.java
+++ b/src/main/java/ru/bclib/mixin/client/MinecraftMixin.java
@@ -3,7 +3,9 @@ package ru.bclib.mixin.client;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.color.block.BlockColors;
 import net.minecraft.client.color.item.ItemColors;
+import net.minecraft.client.gui.screens.Screen;
 import net.minecraft.client.main.GameConfig;
+import net.minecraft.client.multiplayer.ClientLevel;
 import net.minecraft.core.Registry;
 import net.minecraft.core.RegistryAccess.RegistryHolder;
 import net.minecraft.world.level.LevelSettings;
@@ -16,6 +18,7 @@ import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.ModifyArg;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+import ru.bclib.api.dataexchange.DataExchangeAPI;
 import ru.bclib.api.datafixer.DataFixerAPI;
 import ru.bclib.interfaces.CustomColorProvider;
 
@@ -51,6 +54,8 @@ public abstract class MinecraftMixin {
 		if (levelID.startsWith(BCLIB_RECURSION)) {
 			levelID = levelID.substring(BCLIB_RECURSION.length());
 			recursiveCall = true;
+		} else {
+			DataExchangeAPI.prepareServerside();
 		}
 
 		final String recursiveLevelID = BCLIB_RECURSION + levelID;
diff --git a/src/main/resources/bclib.mixins.client.json b/src/main/resources/bclib.mixins.client.json
index 267fb2fb..037950d3 100644
--- a/src/main/resources/bclib.mixins.client.json
+++ b/src/main/resources/bclib.mixins.client.json
@@ -6,6 +6,7 @@
 	"client": [
 		"EnchantingTableBlockMixin",
 		"BackgroundRendererMixin",
+		"GameMixin",
 		"TextureAtlasMixin",
 		"ModelBakeryMixin",
 		"MinecraftMixin"

From 2ae840634a9234ed58b5d2dd088838e8174a1ae5 Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Sun, 1 Aug 2021 11:05:11 +0200
Subject: [PATCH 08/24] Fixed message

---
 .../java/ru/bclib/api/dataexchange/handler/HelloServer.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
index 13d1ce63..481139d5 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
@@ -26,7 +26,7 @@ public class HelloServer extends DataHandler {
 	@Override
 	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
 		String localBclibVersion = HelloClient.getBCLibVersion();
-		BCLib.LOGGER.info("Received Hello from Server. (server="+localBclibVersion+", client="+bclibVersion+")");
+		BCLib.LOGGER.info("Received Hello from Client. (server="+localBclibVersion+", client="+bclibVersion+")");
 		reply(new HelloClient(), server);
 	}
 	

From 589151af815c395614085bc4821fc8f3f5de77cb Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Thu, 5 Aug 2021 18:43:44 +0200
Subject: [PATCH 09/24] Call DataFixer on WorldData

---
 .../ru/bclib/api/datafixer/DataFixerAPI.java  |  7 ++++++
 .../bclib/api/datafixer/MigrationProfile.java | 22 ++++++++++++++++---
 .../java/ru/bclib/api/datafixer/Patch.java    | 17 +++++++++++---
 .../ru/bclib/api/datafixer/PatchFunction.java |  2 +-
 4 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java b/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
index dfdec8d7..b98a8931 100644
--- a/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
+++ b/src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java
@@ -254,6 +254,13 @@ public class DataFixerAPI {
 		players.parallelStream().forEach((file) -> fixPlayer(profile, state, file));
 
 		fixLevel(profile, state, new File(dir, "level.dat"));
+
+		try {
+			profile.patchWorldData();
+		} catch (PatchDidiFailException e){
+			state.didFail = true;
+			BCLib.LOGGER.error(e.getMessage());
+		}
 		
 		if (!state.didFail) {
 			profile.markApplied();
diff --git a/src/main/java/ru/bclib/api/datafixer/MigrationProfile.java b/src/main/java/ru/bclib/api/datafixer/MigrationProfile.java
index 8ad695b6..d58f793c 100644
--- a/src/main/java/ru/bclib/api/datafixer/MigrationProfile.java
+++ b/src/main/java/ru/bclib/api/datafixer/MigrationProfile.java
@@ -2,6 +2,7 @@ package ru.bclib.api.datafixer;
 
 import net.minecraft.nbt.CompoundTag;
 import org.jetbrains.annotations.NotNull;
+import ru.bclib.api.WorldDataAPI;
 
 import java.util.Collections;
 import java.util.HashMap;
@@ -11,10 +12,11 @@ import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
-class MigrationProfile {
+public class MigrationProfile {
 	final Set<String> mods;
 	final Map<String, String> idReplacements;
 	final List<PatchFunction<CompoundTag, Boolean>> levelPatchers;
+	final List<Patch> worldDataPatchers;
 	
 	private final CompoundTag config;
 	
@@ -28,6 +30,7 @@ class MigrationProfile {
 		
 		HashMap<String, String> replacements = new HashMap<String, String>();
 		List<PatchFunction<CompoundTag, Boolean>> levelPatches = new LinkedList<>();
+		List<Patch> worldDataPatches = new LinkedList<>();
 		for (String modID : mods) {
 			Patch.getALL()
 				 .stream()
@@ -37,6 +40,8 @@ class MigrationProfile {
 						 replacements.putAll(patch.getIDReplacements());
 						 if (patch.getLevelDatPatcher()!=null)
 							 levelPatches.add(patch.getLevelDatPatcher());
+						 if (patch.getWorldDataPatcher()!=null)
+							 worldDataPatches.add(patch);
 						 DataFixerAPI.LOGGER.info("Applying " + patch);
 					 }
 					 else {
@@ -47,6 +52,7 @@ class MigrationProfile {
 		
 		this.idReplacements = Collections.unmodifiableMap(replacements);
 		this.levelPatchers = Collections.unmodifiableList(levelPatches);
+		this.worldDataPatchers = Collections.unmodifiableList(worldDataPatches);
 	}
 	
 	final public void markApplied() {
@@ -66,7 +72,7 @@ class MigrationProfile {
 	}
 	
 	public boolean hasAnyFixes() {
-		return idReplacements.size() > 0 || levelPatchers.size() > 0;
+		return idReplacements.size() > 0 || levelPatchers.size() > 0 || worldDataPatchers.size() > 0;
 	}
 	
 	public boolean replaceStringFromIDs(@NotNull CompoundTag tag, @NotNull String key) {
@@ -87,8 +93,18 @@ class MigrationProfile {
 	public boolean patchLevelDat(@NotNull CompoundTag level) throws PatchDidiFailException {
 		boolean changed = false;
 		for (PatchFunction<CompoundTag, Boolean> f : levelPatchers) {
-			changed |= f.apply(level);
+			changed |= f.apply(level, this);
 		}
 		return changed;
 	}
+
+	public void patchWorldData() throws PatchDidiFailException {
+		for (Patch patch : worldDataPatchers) {
+			CompoundTag root = WorldDataAPI.getRootTag(patch.modID);
+			boolean changed = patch.getWorldDataPatcher().apply(root, this);
+			if (changed) {
+				WorldDataAPI.saveFile(patch.modID);
+			}
+		}
+	}
 }
diff --git a/src/main/java/ru/bclib/api/datafixer/Patch.java b/src/main/java/ru/bclib/api/datafixer/Patch.java
index 30db9b4c..e687f3a6 100644
--- a/src/main/java/ru/bclib/api/datafixer/Patch.java
+++ b/src/main/java/ru/bclib/api/datafixer/Patch.java
@@ -124,14 +124,25 @@ public abstract class Patch {
 	 * Return a {@link PatchFunction} that is called with the content of <i>level.dat</i>.
 	 * <p>
 	 * The function needs to return {@code true}, if changes were made to the data.
-	 * If an error occurs, the method shoudl throw a {@link PatchDidiFailException}
+	 * If an error occurs, the method should throw a {@link PatchDidiFailException}
 	 *
 	 * The default implementation of this method returns null.
 	 *
-	 * @return The returned function is called a {@code CompoundTag} that contains the
-	 * contents of <i>level.dat</i>
+	 * @return {@code true} if changes were applied and we need to save the data
 	 */
 	public PatchFunction<CompoundTag, Boolean> getLevelDatPatcher() { return null; }
+
+	/**
+	 * Return a {@link PatchFunction} that is called with the content from the
+	 * {@link ru.bclib.api.WorldDataAPI} for this Mod.
+	 * The function needs to return {@code true}, if changes were made to the data.
+	 * If an error occurs, the method should throw a {@link PatchDidiFailException}
+	 *
+	 * The default implementation of this method returns null.
+	 *
+	 * @return {@code true} if changes were applied and we need to save the data
+	 */
+	public PatchFunction<CompoundTag, Boolean> getWorldDataPatcher() { return null; }
 	
 	/**
 	 * Generates ready to use data for all currently registered patches. The list of
diff --git a/src/main/java/ru/bclib/api/datafixer/PatchFunction.java b/src/main/java/ru/bclib/api/datafixer/PatchFunction.java
index 77c70f6b..7d429d68 100644
--- a/src/main/java/ru/bclib/api/datafixer/PatchFunction.java
+++ b/src/main/java/ru/bclib/api/datafixer/PatchFunction.java
@@ -2,5 +2,5 @@ package ru.bclib.api.datafixer;
 
 @FunctionalInterface
 public interface PatchFunction<T, R> {
-	R apply(T t) throws PatchDidiFailException;
+	R apply(T t, MigrationProfile profile) throws PatchDidiFailException;
 }

From 16cbba6e76506664a8e0b72cb761671fba279044 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Thu, 5 Aug 2021 19:07:14 +0200
Subject: [PATCH 10/24] Preparing Config-Objects to automatically sync from
 Server to Client

---
 .../api/dataexchange/DataExchangeAPI.java     | 25 ++++++++++++++++++-
 src/main/java/ru/bclib/config/Config.java     | 16 +++++++-----
 .../java/ru/bclib/config/ConfigKeeper.java    | 10 ++++----
 .../java/ru/bclib/config/ConfigWriter.java    | 13 ++++------
 src/main/java/ru/bclib/config/PathConfig.java | 10 ++++----
 .../java/ru/bclib/config/SessionConfig.java   | 25 -------------------
 6 files changed, 49 insertions(+), 50 deletions(-)
 delete mode 100644 src/main/java/ru/bclib/config/SessionConfig.java

diff --git a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
index f354928d..e5e53187 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
@@ -6,12 +6,14 @@ import net.fabricmc.api.Environment;
 import net.fabricmc.fabric.api.client.networking.v1.ClientLoginConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
-import net.minecraft.client.Minecraft;
 import net.minecraft.network.FriendlyByteBuf;
 
+import java.io.File;
+import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Predicate;
 
 public class DataExchangeAPI {
 	private final static List<String> MODS = Lists.newArrayList();
@@ -19,6 +21,17 @@ public class DataExchangeAPI {
 	private ConnectorServerside server;
 	private ConnectorClientside client;
 	protected final Set<DataHandlerDescriptor> descriptors;
+
+	private static class AutoFileSyncEntry {
+		public final Predicate<Object> needTransfer;
+		public final File fileName;
+
+		private AutoFileSyncEntry(Predicate<Object> needTransfer, File fileName) {
+			this.needTransfer = needTransfer;
+			this.fileName = fileName;
+		}
+	}
+	protected final List<AutoFileSyncEntry> autoSyncFiles = new ArrayList<>(4);
 	
 	
 	private DataExchangeAPI(){
@@ -141,4 +154,14 @@ public class DataExchangeAPI {
 			}
 		});
 	}
+
+	/**
+	 * Registers a File for automatic client syncing.
+	 *
+	 * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
+	 * @param fileName The name of the File
+	 */
+	public static void addAutoSyncFile(Predicate<Object> needTransfer, File fileName){
+		DataExchangeAPI.getInstance().autoSyncFiles.add(new AutoFileSyncEntry(needTransfer, fileName));
+	}
 }
diff --git a/src/main/java/ru/bclib/config/Config.java b/src/main/java/ru/bclib/config/Config.java
index d5672efe..d49d802f 100644
--- a/src/main/java/ru/bclib/config/Config.java
+++ b/src/main/java/ru/bclib/config/Config.java
@@ -2,6 +2,7 @@ package ru.bclib.config;
 
 import org.jetbrains.annotations.Nullable;
 import ru.bclib.BCLib;
+import ru.bclib.api.dataexchange.DataExchangeAPI;
 import ru.bclib.config.ConfigKeeper.BooleanEntry;
 import ru.bclib.config.ConfigKeeper.Entry;
 import ru.bclib.config.ConfigKeeper.FloatEntry;
@@ -13,16 +14,19 @@ import java.io.File;
 
 public abstract class Config {
 	protected final ConfigKeeper keeper;
-	
+	protected final boolean autoSync;
 	protected abstract void registerEntries();
-	
-	public Config(String modID, String group) {
-		this(modID, group, null);
+
+	protected Config(String modID, String group) {
+		this(modID, group, true);
 	}
 	
-	protected Config(String modID, String group, File path) {
-		this.keeper = new ConfigKeeper(modID, group, path);
+	protected Config(String modID, String group, boolean autoSync) {
+		this.keeper = new ConfigKeeper(modID, group);
 		this.registerEntries();
+		this.autoSync = autoSync;
+
+		DataExchangeAPI.addAutoSyncFile((content)->{return false;}, keeper.getConfigFile());
 	}
 	
 	public void saveChanges() {
diff --git a/src/main/java/ru/bclib/config/ConfigKeeper.java b/src/main/java/ru/bclib/config/ConfigKeeper.java
index 12c1e75e..6c905d05 100644
--- a/src/main/java/ru/bclib/config/ConfigKeeper.java
+++ b/src/main/java/ru/bclib/config/ConfigKeeper.java
@@ -22,13 +22,13 @@ public final class ConfigKeeper {
 	private boolean changed = false;
 	
 	public ConfigKeeper(String modID, String group) {
-		this(modID, group, null);
-	}
-	
-	protected ConfigKeeper(String modID, String group, File path) {
-		this.writer = new ConfigWriter(modID, group, path);
+		this.writer = new ConfigWriter(modID, group);
 		this.configObject = writer.load();
 	}
+
+	File getConfigFile(){
+		return this.writer.getConfigFile();
+	}
 	
 	public void save() {
 		if (!changed) return;
diff --git a/src/main/java/ru/bclib/config/ConfigWriter.java b/src/main/java/ru/bclib/config/ConfigWriter.java
index 35739a71..3320ae7b 100644
--- a/src/main/java/ru/bclib/config/ConfigWriter.java
+++ b/src/main/java/ru/bclib/config/ConfigWriter.java
@@ -15,20 +15,17 @@ public class ConfigWriter {
 	private JsonObject configObject;
 	
 	public ConfigWriter(String modID, String configFile) {
-		this(modID, configFile, null);
-	}
-	
-	public ConfigWriter(String modID, String configFile, File configFolder) {
-		this.configFile = new File((configFolder == null ? GAME_CONFIG_DIR.resolve(modID).toFile() : new File(
-			configFolder,
-			modID
-		)), configFile + ".json");
+		this.configFile = new File(GAME_CONFIG_DIR.resolve(modID).toFile() , configFile + ".json");
 		File parent = this.configFile.getParentFile();
 		if (!parent.exists()) {
 			parent.mkdirs();
 		}
 		this.load();
 	}
+
+	File getConfigFile(){
+		return this.configFile;
+	}
 	
 	public JsonObject getConfig() {
 		return configObject;
diff --git a/src/main/java/ru/bclib/config/PathConfig.java b/src/main/java/ru/bclib/config/PathConfig.java
index ca9d960e..b10388bf 100644
--- a/src/main/java/ru/bclib/config/PathConfig.java
+++ b/src/main/java/ru/bclib/config/PathConfig.java
@@ -8,13 +8,13 @@ import ru.bclib.config.ConfigKeeper.IntegerRange;
 import java.io.File;
 
 public class PathConfig extends Config {
-	
-	public PathConfig(String modID, String group) {
-		this(modID, group, null);
+
+	public PathConfig(String modID, String group, boolean autoSync) {
+		super(modID, group, autoSync);
 	}
 	
-	protected PathConfig(String modID, String group, File path) {
-		super(modID, group, path);
+	public PathConfig(String modID, String group) {
+		super(modID, group);
 	}
 	
 	@Override
diff --git a/src/main/java/ru/bclib/config/SessionConfig.java b/src/main/java/ru/bclib/config/SessionConfig.java
deleted file mode 100644
index 8ceff397..00000000
--- a/src/main/java/ru/bclib/config/SessionConfig.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package ru.bclib.config;
-
-import net.minecraft.server.level.ServerLevel;
-import net.minecraft.world.level.storage.LevelStorageSource;
-import ru.bclib.BCLib;
-
-import java.io.File;
-
-public class SessionConfig extends PathConfig {
-	private static File getWorldFolder(LevelStorageSource.LevelStorageAccess session, ServerLevel world) {
-		File dir = session.getDimensionPath(world.dimension());
-		if (!new File(dir, "level.dat").exists()) {
-			dir = dir.getParentFile();
-		}
-		return dir;
-	}
-	
-	public final File levelFolder;
-	
-	public SessionConfig(String modID, String group, LevelStorageSource.LevelStorageAccess session, ServerLevel world) {
-		super(modID, group, new File(getWorldFolder(session, world), BCLib.MOD_ID+"-config"));
-		
-		this.levelFolder = new File(getWorldFolder(session, world), BCLib.MOD_ID+"-config");
-	}
-}

From 9b92c6cbf28f18bb7390c1f16848f89edeef9366 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Thu, 5 Aug 2021 19:09:34 +0200
Subject: [PATCH 11/24] call `sendOnEnter`

---
 src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java | 2 +-
 src/main/java/ru/bclib/mixin/client/GameMixin.java           | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
index e5e53187..309dc291 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
@@ -140,7 +140,7 @@ public class DataExchangeAPI {
 	/**
 	 * Automatically called before the player enters the world.
 	 * <p>
-	 * This will send all {@link DataHandler}-Objects that have {@link DataHandlerDescriptor#sendBeforeEnter} set to*
+	 * This is automatically called by BCLib. It will send all {@link DataHandler}-Objects that have {@link DataHandlerDescriptor#sendBeforeEnter} set to*
 	 * {@Code true},
 	 */
 	@Environment(EnvType.CLIENT)
diff --git a/src/main/java/ru/bclib/mixin/client/GameMixin.java b/src/main/java/ru/bclib/mixin/client/GameMixin.java
index 0753dd73..940090b7 100644
--- a/src/main/java/ru/bclib/mixin/client/GameMixin.java
+++ b/src/main/java/ru/bclib/mixin/client/GameMixin.java
@@ -13,6 +13,6 @@ public class GameMixin {
 	
 	@Inject(method="onStartGameSession", at=@At("TAIL"))
 	public void bcliv_onStart(CallbackInfo ci){
-		DataExchangeAPI.send(new HelloServer());
+		DataExchangeAPI.sendOnEnter();
 	}
 }

From feee3514a928e20263774722ce623a4d2ab4efd7 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 08:23:23 +0200
Subject: [PATCH 12/24] Unpolute public API

---
 .../ru/bclib/api/dataexchange/Connector.java  |   8 +-
 .../api/dataexchange/ConnectorClientside.java |  20 +--
 .../api/dataexchange/ConnectorServerside.java |  20 +--
 .../api/dataexchange/DataExchangeAPI.java     | 106 ++------------
 .../dataexchange/handler/DataExchange.java    | 133 ++++++++++++++++++
 5 files changed, 172 insertions(+), 115 deletions(-)
 create mode 100644 src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java

diff --git a/src/main/java/ru/bclib/api/dataexchange/Connector.java b/src/main/java/ru/bclib/api/dataexchange/Connector.java
index 55a046a0..6f933489 100644
--- a/src/main/java/ru/bclib/api/dataexchange/Connector.java
+++ b/src/main/java/ru/bclib/api/dataexchange/Connector.java
@@ -1,16 +1,18 @@
 package ru.bclib.api.dataexchange;
 
+import ru.bclib.api.dataexchange.handler.DataExchange;
+
 import java.util.Set;
 
 abstract class Connector {
-	protected final DataExchangeAPI api;
+	protected final DataExchange api;
 	
-	Connector(DataExchangeAPI api) {
+	Connector(DataExchange api) {
 		this.api = api;
 	}
 	public abstract boolean onClient();
 	
 	protected Set<DataHandlerDescriptor> getDescriptors(){
-		return api.descriptors;
+		return api.getDescriptors();
 	}
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/ConnectorClientside.java b/src/main/java/ru/bclib/api/dataexchange/ConnectorClientside.java
index 2e34765f..3ed6fa1f 100644
--- a/src/main/java/ru/bclib/api/dataexchange/ConnectorClientside.java
+++ b/src/main/java/ru/bclib/api/dataexchange/ConnectorClientside.java
@@ -8,11 +8,15 @@ import net.minecraft.client.Minecraft;
 import net.minecraft.client.multiplayer.ClientPacketListener;
 import net.minecraft.network.FriendlyByteBuf;
 import ru.bclib.BCLib;
+import ru.bclib.api.dataexchange.handler.DataExchange;
 
+/**
+ * This is an internal class that handles a Clienetside players Connection to a Server
+ */
 @Environment(EnvType.CLIENT)
-class ConnectorClientside extends Connector {
+public class ConnectorClientside extends Connector {
 	private Minecraft client;
-	ConnectorClientside(DataExchangeAPI api) {
+	ConnectorClientside(DataExchange api) {
 		super(api);
 		this.client = null;
 	}
@@ -23,7 +27,7 @@ class ConnectorClientside extends Connector {
 		return true;
 	}
 	
-	protected void onPlayInit(ClientPacketListener handler, Minecraft client){
+	public void onPlayInit(ClientPacketListener handler, Minecraft client){
 		if (this.client!=null && this.client != client){
 			BCLib.LOGGER.warning("Client changed!");
 		}
@@ -34,8 +38,8 @@ class ConnectorClientside extends Connector {
 			});
 		}
 	}
-	
-	void onPlayReady(ClientPacketListener handler, PacketSender sender, Minecraft client){
+
+	public void onPlayReady(ClientPacketListener handler, PacketSender sender, Minecraft client){
 		for(DataHandlerDescriptor desc : getDescriptors()){
 			if (desc.sendOnJoin){
 				DataHandler h = desc.JOIN_INSTANCE.get();
@@ -45,8 +49,8 @@ class ConnectorClientside extends Connector {
 			}
 		}
 	}
-	
-	void onPlayDisconnect(ClientPacketListener handler, Minecraft client){
+
+	public void onPlayDisconnect(ClientPacketListener handler, Minecraft client){
 		for(DataHandlerDescriptor desc : getDescriptors()) {
 			ClientPlayNetworking.unregisterReceiver(desc.IDENTIFIER);
 		}
@@ -57,7 +61,7 @@ class ConnectorClientside extends Connector {
 		h.receiveFromServer(client, handler, buf, responseSender);
 	}
 	
-	void sendToServer(DataHandler h){
+	public void sendToServer(DataHandler h){
 		if (client==null){
 			throw new RuntimeException("[internal error] Client not initialized yet!");
 		}
diff --git a/src/main/java/ru/bclib/api/dataexchange/ConnectorServerside.java b/src/main/java/ru/bclib/api/dataexchange/ConnectorServerside.java
index b5d7e920..0a42a147 100644
--- a/src/main/java/ru/bclib/api/dataexchange/ConnectorServerside.java
+++ b/src/main/java/ru/bclib/api/dataexchange/ConnectorServerside.java
@@ -7,10 +7,14 @@ import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.server.network.ServerGamePacketListenerImpl;
 import ru.bclib.BCLib;
+import ru.bclib.api.dataexchange.handler.DataExchange;
 
-class ConnectorServerside extends Connector {
+/**
+ * This is an internal class that handles a Serverside Connection to a Client-Player
+ */
+public class ConnectorServerside extends Connector {
 	private MinecraftServer server;
-	ConnectorServerside(DataExchangeAPI api) {
+	ConnectorServerside(DataExchange api) {
 		super(api);
 		server = null;
 	}
@@ -20,7 +24,7 @@ class ConnectorServerside extends Connector {
 		return false;
 	}
 	
-	protected void onPlayInit(ServerGamePacketListenerImpl handler, MinecraftServer server){
+	public void onPlayInit(ServerGamePacketListenerImpl handler, MinecraftServer server){
 		if (this.server!=null && this.server != server){
 			BCLib.LOGGER.warning("Server changed!");
 		}
@@ -31,8 +35,8 @@ class ConnectorServerside extends Connector {
 			});
 		}
 	}
-	
-	void onPlayReady(ServerGamePacketListenerImpl handler, PacketSender sender, MinecraftServer server){
+
+	public void onPlayReady(ServerGamePacketListenerImpl handler, PacketSender sender, MinecraftServer server){
 		for(DataHandlerDescriptor desc : getDescriptors()){
 			if (desc.sendOnJoin){
 				DataHandler h = desc.JOIN_INSTANCE.get();
@@ -42,8 +46,8 @@ class ConnectorServerside extends Connector {
 			}
 		}
 	}
-	
-	void onPlayDisconnect(ServerGamePacketListenerImpl handler, MinecraftServer server){
+
+	public void onPlayDisconnect(ServerGamePacketListenerImpl handler, MinecraftServer server){
 		for(DataHandlerDescriptor desc : getDescriptors()){
 			ServerPlayNetworking.unregisterReceiver(handler, desc.IDENTIFIER);
 		}
@@ -54,7 +58,7 @@ class ConnectorServerside extends Connector {
 		h.receiveFromClient(server, player, handler, buf, responseSender);
 	}
 	
-	void sendToClient(DataHandler h){
+	public void sendToClient(DataHandler h){
 		if (server==null){
 			throw new RuntimeException("[internal error] Server not initialized yet!");
 		}
diff --git a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
index 309dc291..83d8ca53 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
@@ -7,68 +7,24 @@ import net.fabricmc.fabric.api.client.networking.v1.ClientLoginConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
 import net.minecraft.network.FriendlyByteBuf;
+import ru.bclib.api.dataexchange.handler.DataExchange;
 
 import java.io.File;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.function.Predicate;
 
-public class DataExchangeAPI {
+public class DataExchangeAPI extends DataExchange {
 	private final static List<String> MODS = Lists.newArrayList();
-	private static DataExchangeAPI instance;
-	private ConnectorServerside server;
-	private ConnectorClientside client;
-	protected final Set<DataHandlerDescriptor> descriptors;
 
-	private static class AutoFileSyncEntry {
-		public final Predicate<Object> needTransfer;
-		public final File fileName;
+	protected DataExchangeAPI() {
+		super((api) -> new ConnectorClientside(api), (api) -> new ConnectorServerside(api));
+	}
+
 
-		private AutoFileSyncEntry(Predicate<Object> needTransfer, File fileName) {
-			this.needTransfer = needTransfer;
-			this.fileName = fileName;
-		}
-	}
-	protected final List<AutoFileSyncEntry> autoSyncFiles = new ArrayList<>(4);
-	
-	
-	private DataExchangeAPI(){
-		descriptors = new HashSet<>();
-	}
-	
-	static DataExchangeAPI getInstance(){
-		if (instance==null){
-			instance = new DataExchangeAPI();
-		}
-		return instance;
-	}
-	
-	@Environment(EnvType.CLIENT)
-	private void initClientside(){
-		if (client!=null) return;
-		client = new ConnectorClientside(this);
-		ClientLoginConnectionEvents.INIT.register((a, b) ->{
-			System.out.println("INIT");
-		});
-		ClientLoginConnectionEvents.QUERY_START.register((a, b) ->{
-			System.out.println("INIT");
-		});
-		ClientPlayConnectionEvents.INIT.register(client::onPlayInit);
-		ClientPlayConnectionEvents.JOIN.register(client::onPlayReady);
-		ClientPlayConnectionEvents.DISCONNECT.register(client::onPlayDisconnect);
-	}
-	
-	private void initServerSide(){
-		if (server!=null) return;
-		server = new ConnectorServerside(this);
-		
-		ServerPlayConnectionEvents.INIT.register(server::onPlayInit);
-		ServerPlayConnectionEvents.JOIN.register(server::onPlayReady);
-		ServerPlayConnectionEvents.DISCONNECT.register(server::onPlayDisconnect);
-	}
-	
 	/**
 	 * Register a mod to participate in the DataExchange.
 	 *
@@ -91,34 +47,10 @@ public class DataExchangeAPI {
 	 * @param desc The Descriptor you want to add.
 	 */
 	public static void registerDescriptor(DataHandlerDescriptor desc){
-		DataExchangeAPI api = DataExchangeAPI.getInstance();
+		DataExchangeAPI api = DataExchange.getInstance();
 		api.descriptors.add(desc);
 	}
-	
-	
-	/**
-	 * Initializes all datastructures that need to exist in the client component.
-	 * <p>
-	 * This is automatically called by BCLib. You can register {@link DataHandler}-Objects before this Method is called
-	 */
-	@Environment(EnvType.CLIENT)
-	public static void prepareClientside(){
-		DataExchangeAPI api = DataExchangeAPI.getInstance();
-		api.initClientside();
-		
-	}
-	
-	/**
-	 * Initializes all datastructures that need to exist in the server component.
-	 * <p>
-	 * This is automatically called by BCLib. You can register {@link DataHandler}-Objects before this Method is called
-	 */
-	public static void prepareServerside(){
-		DataExchangeAPI api = DataExchangeAPI.getInstance();
-		api.initServerSide();
-	}
-	
-	
+
 	/**
 	 * Sends the Handler.
 	 * <p>
@@ -136,24 +68,6 @@ public class DataExchangeAPI {
 			DataExchangeAPI.getInstance().client.sendToServer(h);
 		}
 	}
-	
-	/**
-	 * Automatically called before the player enters the world.
-	 * <p>
-	 * This is automatically called by BCLib. It will send all {@link DataHandler}-Objects that have {@link DataHandlerDescriptor#sendBeforeEnter} set to*
-	 * {@Code true},
-	 */
-	@Environment(EnvType.CLIENT)
-	public static void sendOnEnter(){
-		getInstance().descriptors.forEach((desc)-> {
-			if (desc.sendBeforeEnter){
-				DataHandler h = desc.JOIN_INSTANCE.get();
-				if (!h.getOriginatesOnServer()) {
-					getInstance().client.sendToServer(h);
-				}
-			}
-		});
-	}
 
 	/**
 	 * Registers a File for automatic client syncing.
@@ -162,6 +76,6 @@ public class DataExchangeAPI {
 	 * @param fileName The name of the File
 	 */
 	public static void addAutoSyncFile(Predicate<Object> needTransfer, File fileName){
-		DataExchangeAPI.getInstance().autoSyncFiles.add(new AutoFileSyncEntry(needTransfer, fileName));
+		DataExchangeAPI.getInstance().addAutoSyncFileData(needTransfer, fileName);
 	}
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
new file mode 100644
index 00000000..138aedc9
--- /dev/null
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
@@ -0,0 +1,133 @@
+package ru.bclib.api.dataexchange.handler;
+
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
+import net.fabricmc.fabric.api.client.networking.v1.ClientLoginConnectionEvents;
+import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
+import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
+import ru.bclib.api.dataexchange.ConnectorClientside;
+import ru.bclib.api.dataexchange.ConnectorServerside;
+import ru.bclib.api.dataexchange.DataExchangeAPI;
+import ru.bclib.api.dataexchange.DataHandler;
+import ru.bclib.api.dataexchange.DataHandlerDescriptor;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.function.Predicate;
+import java.util.function.Supplier;
+
+abstract public class DataExchange {
+    private static class AutoFileSyncEntry {
+        public final Predicate<Object> needTransfer;
+        public final File fileName;
+
+        private AutoFileSyncEntry(Predicate<Object> needTransfer, File fileName) {
+            this.needTransfer = needTransfer;
+            this.fileName = fileName;
+        }
+    }
+
+    private static DataExchangeAPI instance;
+    protected static DataExchangeAPI getInstance(){
+        if (instance==null){
+            instance = new DataExchangeAPI();
+        }
+        return instance;
+    }
+
+    protected ConnectorServerside server;
+    protected ConnectorClientside client;
+    protected final Set<DataHandlerDescriptor> descriptors;
+    protected final List<AutoFileSyncEntry> autoSyncFiles = new ArrayList<>(4);
+
+    private final Function<DataExchange, ConnectorClientside> clientSupplier;
+    private final Function<DataExchange, ConnectorServerside> serverSupplier;
+
+    protected DataExchange(Function<DataExchange, ConnectorClientside> client, Function<DataExchange, ConnectorServerside> server){
+        descriptors = new HashSet<>();
+        this.clientSupplier = client;
+        this.serverSupplier = server;
+    }
+
+    public Set<DataHandlerDescriptor> getDescriptors() { return descriptors; }
+
+    @Environment(EnvType.CLIENT)
+    protected void initClientside(){
+        if (client!=null) return;
+        client = clientSupplier.apply(this);
+        ClientLoginConnectionEvents.INIT.register((a, b) ->{
+            System.out.println("INIT");
+        });
+        ClientLoginConnectionEvents.QUERY_START.register((a, b) ->{
+            System.out.println("INIT");
+        });
+        ClientPlayConnectionEvents.INIT.register(client::onPlayInit);
+        ClientPlayConnectionEvents.JOIN.register(client::onPlayReady);
+        ClientPlayConnectionEvents.DISCONNECT.register(client::onPlayDisconnect);
+    }
+
+    protected void initServerSide(){
+        if (server!=null) return;
+        server = serverSupplier.apply(this);
+
+        ServerPlayConnectionEvents.INIT.register(server::onPlayInit);
+        ServerPlayConnectionEvents.JOIN.register(server::onPlayReady);
+        ServerPlayConnectionEvents.DISCONNECT.register(server::onPlayDisconnect);
+    }
+
+    /**
+     * Initializes all datastructures that need to exist in the client component.
+     * <p>
+     * This is automatically called by BCLib. You can register {@link DataHandler}-Objects before this Method is called
+     */
+    @Environment(EnvType.CLIENT)
+    public void prepareClientside(){
+        DataExchangeAPI api = DataExchangeAPI.getInstance();
+        api.initClientside();
+
+    }
+
+    /**
+     * Initializes all datastructures that need to exist in the server component.
+     * <p>
+     * This is automatically called by BCLib. You can register {@link DataHandler}-Objects before this Method is called
+     */
+    public static void prepareServerside(){
+        DataExchange api = DataExchangeAPI.getInstance();
+        api.initServerSide();
+    }
+
+
+
+    /**
+     * Automatically called before the player enters the world.
+     * <p>
+     * This is automatically called by BCLib. It will send all {@link DataHandler}-Objects that have {@link DataHandlerDescriptor#sendBeforeEnter} set to*
+     * {@Code true},
+     */
+    @Environment(EnvType.CLIENT)
+    public static void sendOnEnter(){
+        getInstance().descriptors.forEach((desc)-> {
+            if (desc.sendBeforeEnter){
+                DataHandler h = desc.JOIN_INSTANCE.get();
+                if (!h.getOriginatesOnServer()) {
+                    getInstance().client.sendToServer(h);
+                }
+            }
+        });
+    }
+
+    /**
+     * Registers a File for automatic client syncing.
+     *
+     * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
+     * @param fileName The name of the File
+     */
+    protected void addAutoSyncFileData(Predicate<Object> needTransfer, File fileName){
+       autoSyncFiles.add(new AutoFileSyncEntry(needTransfer, fileName));
+    }
+}

From 8397ef7ccab910fc4e5f2b0c899b48ab9c6d37b4 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 09:33:11 +0200
Subject: [PATCH 13/24] Added FileHash Object

---
 .../ru/bclib/api/dataexchange/FileHash.java   | 151 ++++++++++++++++++
 1 file changed, 151 insertions(+)
 create mode 100644 src/main/java/ru/bclib/api/dataexchange/FileHash.java

diff --git a/src/main/java/ru/bclib/api/dataexchange/FileHash.java b/src/main/java/ru/bclib/api/dataexchange/FileHash.java
new file mode 100644
index 00000000..867aff49
--- /dev/null
+++ b/src/main/java/ru/bclib/api/dataexchange/FileHash.java
@@ -0,0 +1,151 @@
+package ru.bclib.api.dataexchange;
+
+import net.minecraft.network.FriendlyByteBuf;
+import org.jetbrains.annotations.NotNull;
+import ru.bclib.BCLib;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+import java.util.Objects;
+
+/**
+ * Calculates a hash based on the contents of a File.
+ * <p>
+ * A File-Hash contains the md5-sum of the File, as well as its size and byte-values from defined positions
+ * <p>
+ * You can compare instances using {@link #equals(Object)} to determine if two files are
+ * identical.
+ */
+public class FileHash {
+    /**
+     * The md5-hash of the file
+     */
+    @NotNull
+    public final byte[] md5;
+
+    /**
+     * The size (in bytes) of the input.
+     */
+    public final int size;
+
+    /**
+     * a value that is directly calculated from defined byte positions.
+     */
+    public final int value;
+
+    FileHash(byte[] md5, int size, int value) {
+        Objects.nonNull(md5);
+        this.md5 = md5;
+        this.size = size;
+        this.value = value;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%08x", size)
+            + "-"
+            + String.format("%08x", value)
+            + "-"
+            + getMd5String();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        FileHash that = (FileHash) o;
+        return size == that.size && value == that.value && Arrays.equals(md5, that.md5);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = Objects.hash(size, value);
+        result = 31 * result + Arrays.hashCode(md5);
+        return result;
+    }
+
+    /**
+     * Convert the md5-hash to a human readable string
+     * @return The converted String
+     */
+    public String getMd5String(){
+        return toHexString(md5);
+    }
+    /**
+     * Serializes the Object to a buffer
+     * @param buf The buffer to write to
+     */
+    public void writeString(FriendlyByteBuf buf) {
+        buf.writeInt(size);
+        buf.writeInt(value);
+        buf.writeByteArray(md5);
+    }
+
+    /**
+     *Deserialize a Buffer to a new {@link FileHash}-Object
+     * @param buf Thea buffer to read from
+     * @return The received String
+     */
+    public static FileHash readString(FriendlyByteBuf buf){
+        final int size = buf.readInt();
+        final int value = buf.readInt();
+        final byte[] md5 = buf.readByteArray();
+
+        return new FileHash(md5, size, value);
+    }
+
+    /**
+     * Converts a byte-array to a hex-string representation
+     * @param bytes The source array
+     * @return The resulting string, or an empty String if the input was {@code null}
+     */
+    public static String toHexString(byte[] bytes) {
+        if (bytes==null) return "";
+
+        StringBuilder sb = new StringBuilder();
+        for (byte b : bytes) {
+            sb.append(String.format("%02x", b));
+        }
+        return sb.toString();
+    }
+
+    /**
+     * Create a new {@link FileHash}.
+     * @param file The input file
+     * @return A new Instance. You can compare instances using {@link #equals(Object)} to determine if two files are
+     * identical.
+     */
+    public static FileHash createFromBinary(File file){
+        if (!file.exists()) return null;
+        final Path path = file.toPath();
+
+        int size = 0;
+        byte[] md5 = new byte[0];
+        int value = 0;
+
+        try {
+            byte[] data = Files.readAllBytes(path);
+
+            size = data.length;
+
+            value = size>0 ? (data[size/3] | (data [size/2]<<8) | (data [size/5]<<16)) : -1;
+            if (size>20) value |= data[20]<<24;
+
+            MessageDigest md = MessageDigest.getInstance("MD5");
+            md.update(data);
+            md5 = md.digest();
+
+            return new FileHash(md5, size, value);
+        } catch (IOException e) {
+            BCLib.LOGGER.error("Failed to read file: " + file);
+            return null;
+        } catch (NoSuchAlgorithmException e) {
+            BCLib.LOGGER.error("Unable to build hash for file: " + file);
+        }
+    }
+}

From 119e94520c8cf2ad36df067cbfd2e1301ce670ac Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 17:40:46 +0200
Subject: [PATCH 14/24] Compare files on client/server

---
 .../api/dataexchange/DataExchangeAPI.java     |  68 ++++++++-
 .../bclib/api/dataexchange/DataHandler.java   |  10 +-
 .../ru/bclib/api/dataexchange/FileHash.java   |  83 +++++++++--
 .../dataexchange/handler/DataExchange.java    | 134 ++++++++++++++++--
 .../api/dataexchange/handler/HelloClient.java |  68 +++++++--
 .../api/dataexchange/handler/HelloServer.java |  38 ++++-
 src/main/java/ru/bclib/config/Config.java     |   2 +-
 src/main/java/ru/bclib/util/Pair.java         |  11 ++
 src/main/java/ru/bclib/util/Triple.java       |  10 ++
 9 files changed, 371 insertions(+), 53 deletions(-)
 create mode 100644 src/main/java/ru/bclib/util/Pair.java
 create mode 100644 src/main/java/ru/bclib/util/Triple.java

diff --git a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
index 83d8ca53..e74a6b92 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
@@ -7,9 +7,14 @@ import net.fabricmc.fabric.api.client.networking.v1.ClientLoginConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
 import net.minecraft.network.FriendlyByteBuf;
+import ru.bclib.BCLib;
 import ru.bclib.api.dataexchange.handler.DataExchange;
 
 import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
@@ -20,7 +25,10 @@ import java.util.function.Predicate;
 public class DataExchangeAPI extends DataExchange {
 	private final static List<String> MODS = Lists.newArrayList();
 
-	protected DataExchangeAPI() {
+	/**
+	 * You should never need to create a custom instance of this Object.
+	 */
+	public DataExchangeAPI() {
 		super((api) -> new ConnectorClientside(api), (api) -> new ConnectorServerside(api));
 	}
 
@@ -47,8 +55,8 @@ public class DataExchangeAPI extends DataExchange {
 	 * @param desc The Descriptor you want to add.
 	 */
 	public static void registerDescriptor(DataHandlerDescriptor desc){
-		DataExchangeAPI api = DataExchange.getInstance();
-		api.descriptors.add(desc);
+		DataExchange api = DataExchange.getInstance();
+		api.getDescriptors().add(desc);
 	}
 
 	/**
@@ -72,10 +80,58 @@ public class DataExchangeAPI extends DataExchange {
 	/**
 	 * Registers a File for automatic client syncing.
 	 *
-	 * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
+	 * @param modID The ID of the calling Mod
 	 * @param fileName The name of the File
 	 */
-	public static void addAutoSyncFile(Predicate<Object> needTransfer, File fileName){
-		DataExchangeAPI.getInstance().addAutoSyncFileData(needTransfer, fileName);
+	public static void addAutoSyncFile(String modID, File fileName){
+		getInstance().addAutoSyncFileData(modID, fileName, false, FileHash.NEED_TRANSFER);
+	}
+
+	/**
+	 * Registers a File for automatic client syncing.
+	 *
+	 * @param modID The ID of the calling Mod
+	 * @param uniqueID A unique Identifier for the File. (see {@link ru.bclib.api.dataexchange.FileHash#uniqueID} for
+	 *                 Details
+	 * @param fileName The name of the File
+	 */
+	public static void addAutoSyncFile(String modID, String uniqueID, File fileName){
+		getInstance().addAutoSyncFileData(modID, uniqueID, fileName, false, FileHash.NEED_TRANSFER);
+	}
+
+	/**
+	 * Registers a File for automatic client syncing.
+	 *
+	 * @param modID The ID of the calling Mod
+	 * @param fileName The name of the File
+	 * @param requestContent When {@code true} the content of the file is requested for comparison. This will copy the
+	 *                       entire file from the client to the server.
+	 *                       <p>
+	 *                       You should only use this option, if you need to compare parts of the file in order to decide
+	 *                       If the File needs to be copied. Normally using the {@link ru.bclib.api.dataexchange.FileHash}
+	 *                       for comparison is sufficient.
+	 * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
+	 */
+	public static void addAutoSyncFile(String modID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer){
+		getInstance().addAutoSyncFileData(modID, fileName, requestContent, needTransfer);
+	}
+
+	/**
+	 * Registers a File for automatic client syncing.
+	 *
+	 * @param modID The ID of the calling Mod
+	 * @param uniqueID A unique Identifier for the File. (see {@link ru.bclib.api.dataexchange.FileHash#uniqueID} for
+	 *                 Details
+	 * @param fileName The name of the File
+	 * @param requestContent When {@code true} the content of the file is requested for comparison. This will copy the
+	 *                       entire file from the client to the server.
+	 *                       <p>
+	 *                       You should only use this option, if you need to compare parts of the file in order to decide
+	 *                       If the File needs to be copied. Normally using the {@link ru.bclib.api.dataexchange.FileHash}
+	 *                       for comparison is sufficient.
+	 * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
+	 */
+	public static void addAutoSyncFile(String modID, String uniqueID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer){
+		getInstance().addAutoSyncFileData(modID, uniqueID, fileName, requestContent, needTransfer);
 	}
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/DataHandler.java b/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
index fb11bd25..c9912843 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataHandler.java
@@ -48,16 +48,16 @@ public abstract class DataHandler {
 		deserializeFromIncomingData(buf, responseSender, false);
 		server.execute(() -> runOnGameThread(null, server, false));
 	}
-	
+
+	protected void serializeData(FriendlyByteBuf buf) {
+	}
+
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean isClient){
 	}
 	
 	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient){
 	}
-	
-	protected void serializeData(FriendlyByteBuf buf) {
-	}
-	
+
 	final protected boolean reply(DataHandler message, MinecraftServer server){
 		if (lastMessageSender==null) return false;
 		message.sendToClient(server, lastMessageSender);
diff --git a/src/main/java/ru/bclib/api/dataexchange/FileHash.java b/src/main/java/ru/bclib/api/dataexchange/FileHash.java
index 867aff49..44296b85 100644
--- a/src/main/java/ru/bclib/api/dataexchange/FileHash.java
+++ b/src/main/java/ru/bclib/api/dataexchange/FileHash.java
@@ -3,6 +3,7 @@ package ru.bclib.api.dataexchange;
 import net.minecraft.network.FriendlyByteBuf;
 import org.jetbrains.annotations.NotNull;
 import ru.bclib.BCLib;
+import ru.bclib.api.dataexchange.handler.DataExchange;
 
 import java.io.File;
 import java.io.IOException;
@@ -12,6 +13,7 @@ import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
 import java.util.Objects;
+import java.util.function.Predicate;
 
 /**
  * Calculates a hash based on the contents of a File.
@@ -38,11 +40,47 @@ public class FileHash {
      */
     public final int value;
 
-    FileHash(byte[] md5, int size, int value) {
+    /**
+     * A Unique ID for the referenced File.
+     * <p>
+     * Files with the same {@link #modID} need to have a unique IDs. Normally the filename from {@link #FileHash(String, File, byte[], int, int)}
+     * is used to generated that ID, but you can directly specify one using {@link #FileHash(String, String, byte[], int, int)}.
+     */
+    @NotNull
+    public final String uniqueID;
+
+    /**
+     * The ID of the Mod that is registering the File
+     */
+    @NotNull
+    public final String modID;
+
+    FileHash(String modID, File file, byte[] md5, int size, int value) {
+        this(modID, file.getName(), md5, size, value);
+    }
+
+    FileHash(String modID, String uniqueID, byte[] md5, int size, int value) {
+        Objects.nonNull(modID);
+        Objects.nonNull(uniqueID);
         Objects.nonNull(md5);
+
         this.md5 = md5;
         this.size = size;
         this.value = value;
+        this.modID = modID;
+        this.uniqueID = uniqueID;
+    }
+
+    private static int ERR_DOES_NOT_EXIST = -10;
+    private static int ERR_IO_ERROR = -20;
+    static FileHash createForEmpty(String modID, String uniqueID, int errCode){
+        return new FileHash(modID, uniqueID, new byte[0], 0, errCode);
+    }
+
+    final static DataExchange.NeedTransferPredicate NEED_TRANSFER = (clientHash, serverHash, content)-> !clientHash.equals(serverHash);
+
+    public boolean noFile() {
+        return md5.length == 0;
     }
 
     @Override
@@ -58,13 +96,13 @@ public class FileHash {
     public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
-        FileHash that = (FileHash) o;
-        return size == that.size && value == that.value && Arrays.equals(md5, that.md5);
+        FileHash fileHash = (FileHash) o;
+        return size == fileHash.size && value == fileHash.value && Arrays.equals(md5, fileHash.md5) && uniqueID.equals(fileHash.uniqueID) && modID.equals(fileHash.modID);
     }
 
     @Override
     public int hashCode() {
-        int result = Objects.hash(size, value);
+        int result = Objects.hash(size, value, uniqueID, modID);
         result = 31 * result + Arrays.hashCode(md5);
         return result;
     }
@@ -76,14 +114,17 @@ public class FileHash {
     public String getMd5String(){
         return toHexString(md5);
     }
+
     /**
      * Serializes the Object to a buffer
      * @param buf The buffer to write to
      */
-    public void writeString(FriendlyByteBuf buf) {
+    public void serialize(FriendlyByteBuf buf) {
         buf.writeInt(size);
         buf.writeInt(value);
         buf.writeByteArray(md5);
+        DataHandler.writeString(buf, modID);
+        DataHandler.writeString(buf, uniqueID);
     }
 
     /**
@@ -91,12 +132,14 @@ public class FileHash {
      * @param buf Thea buffer to read from
      * @return The received String
      */
-    public static FileHash readString(FriendlyByteBuf buf){
+    public static FileHash deserialize(FriendlyByteBuf buf){
         final int size = buf.readInt();
         final int value = buf.readInt();
         final byte[] md5 = buf.readByteArray();
+        final String modID = DataHandler.readString(buf);
+        final String uniqueID = DataHandler.readString(buf);
 
-        return new FileHash(md5, size, value);
+        return new FileHash(modID, uniqueID, md5, size, value);
     }
 
     /**
@@ -116,12 +159,28 @@ public class FileHash {
 
     /**
      * Create a new {@link FileHash}.
+     * <p>
+     * Will call {@link #create(String, File, String)} using the name of the File as {@code uniqueID}.
+     * @param modID ID of the calling Mod
      * @param file The input file
+     *
      * @return A new Instance. You can compare instances using {@link #equals(Object)} to determine if two files are
-     * identical.
+     * identical. Will return {@code null} when an error occurs or the File does not exist
      */
-    public static FileHash createFromBinary(File file){
-        if (!file.exists()) return null;
+    public static FileHash create(String modID, File file){
+        return create(modID, file, file.getName());
+    }
+
+    /**
+     * Create a new {@link FileHash}.
+     * @param modID ID of the calling Mod
+     * @param file The input file
+     * @param uniqueID The unique ID that is used for this File (see {@link FileHash#uniqueID} for Details.
+     * @return A new Instance. You can compare instances using {@link #equals(Object)} to determine if two files are
+     * identical. Will return {@code null} when an error occurs or the File does not exist
+     */
+    public static FileHash create(String modID, File file, String uniqueID){
+        if (!file.exists()) return createForEmpty(modID, uniqueID, ERR_DOES_NOT_EXIST);
         final Path path = file.toPath();
 
         int size = 0;
@@ -140,12 +199,14 @@ public class FileHash {
             md.update(data);
             md5 = md.digest();
 
-            return new FileHash(md5, size, value);
+            return new FileHash(modID, uniqueID, md5, size, value);
         } catch (IOException e) {
             BCLib.LOGGER.error("Failed to read file: " + file);
             return null;
         } catch (NoSuchAlgorithmException e) {
             BCLib.LOGGER.error("Unable to build hash for file: " + file);
         }
+
+        return createForEmpty(modID, uniqueID,  ERR_IO_ERROR);
     }
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
index 138aedc9..c0b87c11 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
@@ -5,29 +5,117 @@ import net.fabricmc.api.Environment;
 import net.fabricmc.fabric.api.client.networking.v1.ClientLoginConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
+import net.minecraft.network.FriendlyByteBuf;
 import ru.bclib.api.dataexchange.ConnectorClientside;
 import ru.bclib.api.dataexchange.ConnectorServerside;
 import ru.bclib.api.dataexchange.DataExchangeAPI;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
+import ru.bclib.api.dataexchange.FileHash;
+import ru.bclib.util.Pair;
+import ru.bclib.util.Triple;
 
 import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.function.Predicate;
-import java.util.function.Supplier;
 
 abstract public class DataExchange {
-    private static class AutoFileSyncEntry {
-        public final Predicate<Object> needTransfer;
-        public final File fileName;
+    @FunctionalInterface
+    public interface NeedTransferPredicate  {
+        public boolean test(FileHash clientHash, FileHash serverHash, byte[] content);
+    }
 
-        private AutoFileSyncEntry(Predicate<Object> needTransfer, File fileName) {
+    final static class AutoSyncTriple extends Triple<FileHash, byte[], DataExchange.AutoFileSyncEntry>{
+        public AutoSyncTriple(FileHash first, byte[] second, AutoFileSyncEntry third) {
+            super(first, second, third);
+        }
+    }
+    static class AutoFileSyncEntry {
+        public final NeedTransferPredicate needTransfer;
+        public final File fileName;
+        public final String modID;
+        public final String uniqueID;
+        public final boolean requestContent;
+        private FileHash hash;
+
+        AutoFileSyncEntry(String modID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer) {
+            this(modID, fileName.getName(), fileName, requestContent, needTransfer);
+        }
+
+        AutoFileSyncEntry(String modID, String uniqueID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer) {
             this.needTransfer = needTransfer;
             this.fileName = fileName;
+            this.modID = modID;
+            this.uniqueID = uniqueID;
+            this.requestContent = requestContent;
+        }
+
+        public FileHash getFileHash(){
+            if (hash == null) {
+                hash = FileHash.create(modID, fileName, uniqueID);
+            }
+            return hash;
+        }
+
+        public byte[] getContent(){
+            if (!fileName.exists()) return new byte[0];
+            final Path path = fileName.toPath();
+
+            try {
+                return Files.readAllBytes(path);
+            } catch (IOException e) {
+
+            }
+            return new byte[0];
+        }
+
+
+        public void serialize(FriendlyByteBuf buf){
+            getFileHash().serialize(buf);
+            buf.writeBoolean(requestContent);
+
+            if (requestContent) {
+                byte[] content = getContent();
+                buf.writeInt(content.length);
+                buf.writeByteArray(content);
+            }
+        }
+
+        public static AutoSyncTriple deserializeAndMatch(FriendlyByteBuf buf){
+            Pair<FileHash, byte[]> e = deserialize(buf);
+            AutoFileSyncEntry match = findMatching(e.first);
+            return new AutoSyncTriple(e.first, e.second, match);
+        }
+
+        public static Pair<FileHash, byte[]> deserialize(FriendlyByteBuf buf){
+            FileHash hash = FileHash.deserialize(buf);
+            boolean withContent = buf.readBoolean();
+            byte[] data = null;
+            if (withContent) {
+                int size = buf.readInt();
+                data = buf.readByteArray(size);
+            }
+
+            return new Pair(hash, data);
+        }
+
+        public static AutoFileSyncEntry findMatching(FileHash hash){
+            return DataExchange
+                    .getInstance()
+                    .autoSyncFiles
+                    .stream()
+                    .filter(asf -> asf.modID.equals(hash.modID) && asf.uniqueID.equals(hash.uniqueID))
+                    .findFirst()
+                    .orElse(null);
         }
     }
 
@@ -85,8 +173,8 @@ abstract public class DataExchange {
      * This is automatically called by BCLib. You can register {@link DataHandler}-Objects before this Method is called
      */
     @Environment(EnvType.CLIENT)
-    public void prepareClientside(){
-        DataExchangeAPI api = DataExchangeAPI.getInstance();
+    public static void prepareClientside(){
+        DataExchange api = DataExchange.getInstance();
         api.initClientside();
 
     }
@@ -97,7 +185,7 @@ abstract public class DataExchange {
      * This is automatically called by BCLib. You can register {@link DataHandler}-Objects before this Method is called
      */
     public static void prepareServerside(){
-        DataExchange api = DataExchangeAPI.getInstance();
+        DataExchange api = DataExchange.getInstance();
         api.initServerSide();
     }
 
@@ -124,10 +212,36 @@ abstract public class DataExchange {
     /**
      * Registers a File for automatic client syncing.
      *
+     * @param modID The ID of the calling Mod
      * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
      * @param fileName The name of the File
+     * @param requestContent When {@code true} the content of the file is requested for comparison. This will copy the
+     *                       entire file from the client to the server.
+     *                       <p>
+     *                       You should only use this option, if you need to compare parts of the file in order to decide
+     *                       If the File needs to be copied. Normally using the {@link ru.bclib.api.dataexchange.FileHash}
+     *                       for comparison is sufficient.
      */
-    protected void addAutoSyncFileData(Predicate<Object> needTransfer, File fileName){
-       autoSyncFiles.add(new AutoFileSyncEntry(needTransfer, fileName));
+    protected void addAutoSyncFileData(String modID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer){
+        autoSyncFiles.add(new AutoFileSyncEntry(modID, fileName, requestContent, needTransfer));
+    }
+
+    /**
+     * Registers a File for automatic client syncing.
+     *
+     * @param modID The ID of the calling Mod
+     * @param uniqueID A unique Identifier for the File. (see {@link ru.bclib.api.dataexchange.FileHash#uniqueID} for
+     *                 Details
+     * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
+     * @param fileName The name of the File
+     * @param requestContent When {@code true} the content of the file is requested for comparison. This will copy the
+     *                       entire file from the client to the server.
+     *                       <p>
+     *                       You should only use this option, if you need to compare parts of the file in order to decide
+     *                       If the File needs to be copied. Normally using the {@link ru.bclib.api.dataexchange.FileHash}
+     *                       for comparison is sufficient.
+     */
+    protected void addAutoSyncFileData(String modID, String uniqueID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer){
+       autoSyncFiles.add(new AutoFileSyncEntry(modID, uniqueID, fileName, requestContent, needTransfer));
     }
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index 6bdccd89..758ed4ae 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -7,7 +7,6 @@ import net.fabricmc.loader.api.FabricLoader;
 import net.fabricmc.loader.api.ModContainer;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.screens.Screen;
-import net.minecraft.client.gui.screens.worldselection.EditWorldScreen;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
@@ -15,10 +14,12 @@ import ru.bclib.BCLib;
 import ru.bclib.api.dataexchange.DataExchangeAPI;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
+import ru.bclib.api.dataexchange.FileHash;
 import ru.bclib.api.datafixer.DataFixerAPI;
-import ru.bclib.gui.screens.ConfirmFixScreen;
 import ru.bclib.gui.screens.WarnBCLibVersionMismatch;
+import ru.bclib.util.Triple;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -26,6 +27,11 @@ import java.util.Map.Entry;
 import java.util.Optional;
 import java.util.function.Consumer;
 
+/**
+ * Sent from the Server to the Client.
+ * <p>
+ * For Details refer to {@link HelloServer}
+ */
 public class HelloClient extends DataHandler {
 	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "hello_client"), HelloClient::new, false, false);
 	
@@ -45,20 +51,56 @@ public class HelloClient extends DataHandler {
 	static String getBCLibVersion(){
 		return getModVersion(BCLib.MOD_ID);
 	}
+
+	@Override
+	protected void serializeData(FriendlyByteBuf buf) {
+		final List<String> mods = DataExchangeAPI.registeredMods();
+
+		//write BCLibVersion (=protocol version)
+		buf.writeInt(DataFixerAPI.getModVersion(getBCLibVersion()));
+
+		//write Plugin Versions
+		buf.writeInt(mods.size());
+		for (String modID : mods) {
+			writeString(buf, modID);
+			buf.writeInt(DataFixerAPI.getModVersion(getModVersion(modID)));
+		}
+
+		//send config Data
+		final List<DataExchange.AutoFileSyncEntry> autoSyncFiles = DataExchange.getInstance().autoSyncFiles;
+		buf.writeInt(autoSyncFiles.size());
+		for (DataExchange.AutoFileSyncEntry entry : autoSyncFiles) {
+			System.out.println("Serializing " + entry.getFileHash());
+			entry.serialize(buf);
+		}
+	}
 	
 	String bclibVersion ="0.0.0";
 	Map<String, String> modVersion = new HashMap<>();
+	List<DataExchange.AutoSyncTriple> autoSyncedFiles = null;
 	@Override
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
+		//read BCLibVersion (=protocol version)
 		bclibVersion = DataFixerAPI.getModVersion(buf.readInt());
+
+		//read Plugin Versions
 		modVersion = new HashMap<>();
-		
 		int count = buf.readInt();
-		for (int i=0; i< count; i++){
+		for (int i=0; i< count; i++) {
 			String id = readString(buf);
 			String version = DataFixerAPI.getModVersion(buf.readInt());
 			modVersion.put(id, version);
 		}
+
+		//read config Data
+		count = buf.readInt();
+		autoSyncedFiles = new ArrayList<>(count);
+		for (int i=0; i< count; i++) {
+			System.out.println("Deserializing ");
+			DataExchange.AutoSyncTriple t = DataExchange.AutoFileSyncEntry.deserializeAndMatch(buf);
+			autoSyncedFiles.add(t);
+			System.out.println(t.first);
+		}
 	}
 	
 	@Override
@@ -75,17 +117,13 @@ public class HelloClient extends DataHandler {
 			String ver = getModVersion(e.getKey());
 			BCLib.LOGGER.info("    - " + e.getKey() + " (client="+ver+", server="+ver+")");
 		}
-	}
-	
-	@Override
-	protected void serializeData(FriendlyByteBuf buf) {
-		final List<String> mods = DataExchangeAPI.registeredMods();
-		buf.writeInt(DataFixerAPI.getModVersion(getBCLibVersion()));
-		
-		buf.writeInt(mods.size());
-		for (String modID : mods) {
-			writeString(buf, modID);
-			buf.writeInt(DataFixerAPI.getModVersion(getModVersion(modID)));
+
+		for (DataExchange.AutoSyncTriple e : autoSyncedFiles) {
+			if (e.third == null) {
+				BCLib.LOGGER.info("    - File " + e.first.modID + "." + e.first.uniqueID + ": Does not exist on client.");
+			} else if (e.third.needTransfer.test(e.third.getFileHash(), e.first, e.second)) {
+				BCLib.LOGGER.info("    - File " + e.first.modID + "." + e.first.uniqueID + ": Needs Transfer");
+			}
 		}
 	}
 	
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
index 481139d5..411de2b1 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
@@ -10,6 +10,34 @@ import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
 import ru.bclib.api.datafixer.DataFixerAPI;
 
+/**
+ * This message is sent once a player enters the world. It initiates a sequence of Messages that will sync files between both
+ * client and server.
+ * <p>
+ * <tab<le>
+ *     <tr>
+ *         <th>Server</th>
+ *         <th></th>
+ *         <th>Client</th>
+ *         <th></th>
+ *     </tr>
+ *     <tr>
+ *         <td colspan="4">Player enters World</td>
+ *     </tr>
+ *     <tr>
+ *         <td></td>
+ *         <td>&lt;--</td>
+ *         <td>{@link HelloServer}</td>
+ *         <td>Sends the current BLib-Version installed on the Client</td>
+ *     </tr>
+ *	   <tr>
+ *         <td>{@link HelloClient}</td>
+ *         <td>--&gt;</td>
+ *         <td></td>
+ *         <td>Sends the current BClIb-Version and the Version of all Plugins on the Server</td>
+ *     </tr>
+ * </table>
+ */
 public class HelloServer extends DataHandler {
 	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "hello_server"), HelloServer::new, false, true);
 	
@@ -17,6 +45,11 @@ public class HelloServer extends DataHandler {
 	public HelloServer() {
 		super(DESCRIPTOR.IDENTIFIER, false);
 	}
+
+	@Override
+	protected void serializeData(FriendlyByteBuf buf) {
+		buf.writeInt(DataFixerAPI.getModVersion(HelloClient.getBCLibVersion()));
+	}
 	
 	@Override
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
@@ -29,9 +62,4 @@ public class HelloServer extends DataHandler {
 		BCLib.LOGGER.info("Received Hello from Client. (server="+localBclibVersion+", client="+bclibVersion+")");
 		reply(new HelloClient(), server);
 	}
-	
-	@Override
-	protected void serializeData(FriendlyByteBuf buf) {
-		buf.writeInt(DataFixerAPI.getModVersion(HelloClient.getBCLibVersion()));
-	}
 }
diff --git a/src/main/java/ru/bclib/config/Config.java b/src/main/java/ru/bclib/config/Config.java
index d49d802f..d2280eb9 100644
--- a/src/main/java/ru/bclib/config/Config.java
+++ b/src/main/java/ru/bclib/config/Config.java
@@ -26,7 +26,7 @@ public abstract class Config {
 		this.registerEntries();
 		this.autoSync = autoSync;
 
-		DataExchangeAPI.addAutoSyncFile((content)->{return false;}, keeper.getConfigFile());
+		DataExchangeAPI.addAutoSyncFile(BCLib.MOD_ID, "CONFIG_"+modID+"_"+group, keeper.getConfigFile());
 	}
 	
 	public void saveChanges() {
diff --git a/src/main/java/ru/bclib/util/Pair.java b/src/main/java/ru/bclib/util/Pair.java
new file mode 100644
index 00000000..61ceb6eb
--- /dev/null
+++ b/src/main/java/ru/bclib/util/Pair.java
@@ -0,0 +1,11 @@
+package ru.bclib.util;
+
+public class Pair <A, B>{
+    public final A first;
+    public final B second;
+
+    public Pair(A first, B second) {
+        this.first = first;
+        this.second = second;
+    }
+}
diff --git a/src/main/java/ru/bclib/util/Triple.java b/src/main/java/ru/bclib/util/Triple.java
new file mode 100644
index 00000000..df88cf75
--- /dev/null
+++ b/src/main/java/ru/bclib/util/Triple.java
@@ -0,0 +1,10 @@
+package ru.bclib.util;
+
+public class Triple <A, B, C> extends Pair<A, B>{
+    public final C third;
+
+    public Triple(A first, B second, C third) {
+        super(first, second);
+        this.third = third;
+    }
+}

From 869dc762fad4c18ab324e3b47be83f66f8414975 Mon Sep 17 00:00:00 2001
From: Frank Bauer <developer@ambertation.de>
Date: Fri, 6 Aug 2021 19:19:49 +0200
Subject: [PATCH 15/24] Send file requests

---
 .../dataexchange/handler/DataExchange.java    | 19 ++++++
 .../api/dataexchange/handler/HelloClient.java | 42 ++++++++++---
 .../api/dataexchange/handler/HelloServer.java | 20 ++++++-
 .../dataexchange/handler/RequestFiles.java    | 60 +++++++++++++++++++
 .../api/dataexchange/handler/SendFiles.java   | 33 ++++++++++
 5 files changed, 163 insertions(+), 11 deletions(-)
 create mode 100644 src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
 create mode 100644 src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java

diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
index c0b87c11..fbaa3a75 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
@@ -33,11 +33,30 @@ abstract public class DataExchange {
     public interface NeedTransferPredicate  {
         public boolean test(FileHash clientHash, FileHash serverHash, byte[] content);
     }
+    
+    final static class AutoSyncID extends Pair<String, String>{
+        public AutoSyncID(String modID, String uniqueID) {
+            super(modID, uniqueID);
+        }
+        
+        public String getModID() { return this.first; }
+        public String getUniqueID() { return this.second; }
+    
+        @Override
+        public String toString() {
+            return first+"."+second;
+        }
+    }
 
     final static class AutoSyncTriple extends Triple<FileHash, byte[], DataExchange.AutoFileSyncEntry>{
         public AutoSyncTriple(FileHash first, byte[] second, AutoFileSyncEntry third) {
             super(first, second, third);
         }
+    
+        @Override
+        public String toString() {
+            return first.modID+"."+first.uniqueID;
+        }
     }
     static class AutoFileSyncEntry {
         public final NeedTransferPredicate needTransfer;
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index 758ed4ae..05176c16 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -14,10 +14,9 @@ import ru.bclib.BCLib;
 import ru.bclib.api.dataexchange.DataExchangeAPI;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
-import ru.bclib.api.dataexchange.FileHash;
+import ru.bclib.api.dataexchange.handler.DataExchange.AutoSyncID;
 import ru.bclib.api.datafixer.DataFixerAPI;
 import ru.bclib.gui.screens.WarnBCLibVersionMismatch;
-import ru.bclib.util.Triple;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -108,22 +107,35 @@ public class HelloClient extends DataHandler {
 		String localBclibVersion = getBCLibVersion();
 		BCLib.LOGGER.info("Received Hello from Server. (client="+localBclibVersion+", server="+bclibVersion+")");
 		
-		if (DataFixerAPI.getModVersion(localBclibVersion) == DataFixerAPI.getModVersion(bclibVersion)){
+		if (DataFixerAPI.getModVersion(localBclibVersion) != DataFixerAPI.getModVersion(bclibVersion)){
 			showBCLibError(client);
 			return;
 		}
 		
+		List<AutoSyncID> filesToRequest = new ArrayList<>(4);
+		
 		for (Entry<String, String> e : modVersion.entrySet()){
 			String ver = getModVersion(e.getKey());
 			BCLib.LOGGER.info("    - " + e.getKey() + " (client="+ver+", server="+ver+")");
 		}
-
+		
+		BCLib.LOGGER.info("Server offered Files to sync.");
 		for (DataExchange.AutoSyncTriple e : autoSyncedFiles) {
+			boolean willRequest = false;
 			if (e.third == null) {
-				BCLib.LOGGER.info("    - File " + e.first.modID + "." + e.first.uniqueID + ": Does not exist on client.");
+				filesToRequest.add(new AutoSyncID(e.first.modID, e.first.uniqueID));
+				willRequest = true;
+				BCLib.LOGGER.info("    - File " + e + ": Does not exist on client.");
 			} else if (e.third.needTransfer.test(e.third.getFileHash(), e.first, e.second)) {
-				BCLib.LOGGER.info("    - File " + e.first.modID + "." + e.first.uniqueID + ": Needs Transfer");
+				willRequest = true;
+				filesToRequest.add(new AutoSyncID(e.first.modID, e.first.uniqueID));
+				BCLib.LOGGER.info("    - File " + e + ": Needs Transfer");
 			}
+			
+			BCLib.LOGGER.info("    - " + e + ": " + (willRequest ? " (requesting)":""));
+		}
+		if (filesToRequest.size()>0) {
+			showDonwloadConfigs(client, filesToRequest);
 		}
 	}
 	
@@ -133,14 +145,28 @@ public class HelloClient extends DataHandler {
 		client.setScreen(new WarnBCLibVersionMismatch((download) -> {
 			Minecraft.getInstance().setScreen((Screen)null);
 			if (download){
-				requestDownloads((hadErrors)->{
+				requestBCLibDownload((hadErrors)->{
 					client.stop();
 				});
 			}
 		}));
 	}
 	
-	private void requestDownloads(Consumer<Boolean> whenFinished){
+	@Environment(EnvType.CLIENT)
+	protected void showDonwloadConfigs(Minecraft client, List<AutoSyncID> files){
+		requestFileDownloads((hadErrors)->{
+			client.stop();
+		}, files);
+	}
+	
+	private void requestBCLibDownload(Consumer<Boolean> whenFinished){
 		BCLib.LOGGER.warning("Starting download of BCLib");
+		whenFinished.accept(true);
+	}
+	
+	private void requestFileDownloads(Consumer<Boolean> whenFinished, List<AutoSyncID> files){
+		BCLib.LOGGER.info("Starting download of Files:" + files.size());
+		DataExchangeAPI.send(new RequestFiles(files));
+		whenFinished.accept(true);
 	}
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
index 4ffd91be..57fb5668 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloServer.java
@@ -1,8 +1,7 @@
 package ru.bclib.api.dataexchange.handler;
 
 import net.fabricmc.fabric.api.networking.v1.PacketSender;
-import net.fabricmc.loader.api.FabricLoader;
-import net.fabricmc.loader.api.ModContainer;
+import net.minecraft.client.Minecraft;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
@@ -12,6 +11,8 @@ import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
 import ru.bclib.api.datafixer.DataFixerAPI;
 
+import java.io.File;
+
 /**
  * This message is sent once a player enters the world. It initiates a sequence of Messages that will sync files between both
  * client and server.
@@ -36,7 +37,20 @@ import ru.bclib.api.datafixer.DataFixerAPI;
  *         <td>{@link HelloClient}</td>
  *         <td>--&gt;</td>
  *         <td></td>
- *         <td>Sends the current BClIb-Version and the Version of all Plugins on the Server</td>
+ *         <td>Sends the current BClIb-Version, the Version of all Plugins and data for all AutpoSync-Files
+ *         ({@link DataExchangeAPI#addAutoSyncFile(String, File)} on the Server</td>
+ *     </tr>
+ *     <tr>
+ *         <td></td>
+ *         <td>&lt;--</td>
+ *         <td>{@link RequestFiles}</td>
+ *         <td>Request missing or out of sync Files from the Server</td>
+ *     </tr>
+ *     <tr>
+ *         <td>{@link SendFiles}</td>
+ *         <td>--&gt;</td>
+ *         <td></td>
+ *         <td>Send Files from the Server to the Client</td>
  *     </tr>
  * </table>
  */
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
new file mode 100644
index 00000000..9a716055
--- /dev/null
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
@@ -0,0 +1,60 @@
+package ru.bclib.api.dataexchange.handler;
+
+import net.fabricmc.fabric.api.networking.v1.PacketSender;
+import net.minecraft.client.Minecraft;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MinecraftServer;
+import ru.bclib.BCLib;
+import ru.bclib.api.dataexchange.DataHandler;
+import ru.bclib.api.dataexchange.DataHandlerDescriptor;
+import ru.bclib.api.dataexchange.handler.DataExchange.AutoSyncID;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class RequestFiles extends DataHandler {
+	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "request_files"), RequestFiles::new, false, false);
+	
+	protected List<AutoSyncID> files;
+	private RequestFiles(){
+		this(null);
+	}
+	
+	public RequestFiles(List<AutoSyncID> files) {
+		super(DESCRIPTOR.IDENTIFIER, false);
+		this.files = files;
+	}
+	
+	@Override
+	protected void serializeData(FriendlyByteBuf buf) {
+		buf.writeInt(files.size());
+		
+		for (AutoSyncID a : files){
+			writeString(buf, a.getModID());
+			writeString(buf, a.getUniqueID());
+		}
+	}
+	
+	@Override
+	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
+		int size = buf.readInt();
+		files = new ArrayList<>(size);
+		
+		BCLib.LOGGER.info("Client requested " + size + " Files:");
+		for (int i=0; i<size; i++){
+			String modID = readString(buf);
+			String uID = readString(buf);
+			AutoSyncID asid = new AutoSyncID(modID, uID);
+			files.add(asid);
+			BCLib.LOGGER.info("    - " + asid);
+		}
+		
+		
+	}
+	
+	@Override
+	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
+	
+	}
+}
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
new file mode 100644
index 00000000..ecd7ef23
--- /dev/null
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
@@ -0,0 +1,33 @@
+package ru.bclib.api.dataexchange.handler;
+
+import net.fabricmc.fabric.api.networking.v1.PacketSender;
+import net.minecraft.client.Minecraft;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MinecraftServer;
+import ru.bclib.BCLib;
+import ru.bclib.api.dataexchange.DataHandler;
+import ru.bclib.api.dataexchange.DataHandlerDescriptor;
+
+public class SendFiles extends DataHandler {
+	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "send_files"), SendFiles::new, false, false);
+	
+	public SendFiles() {
+		super(DESCRIPTOR.IDENTIFIER, true);
+	}
+	
+	@Override
+	protected void serializeData(FriendlyByteBuf buf) {
+	
+	}
+	
+	@Override
+	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
+	
+	}
+	
+	@Override
+	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
+	
+	}
+}

From d01b7923aa4895d9ed1415b4f65db7dc71b05d6e Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 21:27:33 +0200
Subject: [PATCH 16/24] Receive requested file contents on client

---
 .../dataexchange/handler/DataExchange.java    | 43 ++++++++++++++++---
 .../dataexchange/handler/RequestFiles.java    |  8 +++-
 .../api/dataexchange/handler/SendFiles.java   | 30 +++++++++++--
 3 files changed, 70 insertions(+), 11 deletions(-)

diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
index fbaa3a75..a5b0a1d7 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
@@ -97,15 +97,27 @@ abstract public class DataExchange {
             return new byte[0];
         }
 
+        public void serializeContent(FriendlyByteBuf buf){
+            DataHandler.writeString(buf, modID);
+            DataHandler.writeString(buf, uniqueID);
+            serializeFileContent(buf);
+        }
+        public static Pair<AutoFileSyncEntry, byte[]> deserializeContent(FriendlyByteBuf buf){
+            final String modID = DataHandler.readString(buf);
+            final String uniqueID = DataHandler.readString(buf);
+            byte[] data = deserializeFileContent(buf);
 
+            AutoFileSyncEntry entry = AutoFileSyncEntry.findMatching(modID, uniqueID);
+            return new Pair<>(entry, data);
+        }
+
+        
         public void serialize(FriendlyByteBuf buf){
             getFileHash().serialize(buf);
             buf.writeBoolean(requestContent);
 
             if (requestContent) {
-                byte[] content = getContent();
-                buf.writeInt(content.length);
-                buf.writeByteArray(content);
+                serializeFileContent(buf);
             }
         }
 
@@ -120,19 +132,38 @@ abstract public class DataExchange {
             boolean withContent = buf.readBoolean();
             byte[] data = null;
             if (withContent) {
-                int size = buf.readInt();
-                data = buf.readByteArray(size);
+                data = deserializeFileContent(buf);
             }
 
             return new Pair(hash, data);
         }
 
+        private void serializeFileContent(FriendlyByteBuf buf) {
+            byte[] content = getContent();
+            buf.writeInt(content.length);
+            buf.writeByteArray(content);
+        }
+
+        private static byte[] deserializeFileContent(FriendlyByteBuf buf) {
+            byte[] data;
+            int size = buf.readInt();
+            data = buf.readByteArray(size);
+            return data;
+        }
+
         public static AutoFileSyncEntry findMatching(FileHash hash){
+            return findMatching(hash.modID, hash.uniqueID);
+        }
+        public static AutoFileSyncEntry findMatching(AutoSyncID aid){
+            return findMatching(aid.getModID(), aid.getUniqueID());
+        }
+
+        public static AutoFileSyncEntry findMatching(String modID, String uniqueID){
             return DataExchange
                     .getInstance()
                     .autoSyncFiles
                     .stream()
-                    .filter(asf -> asf.modID.equals(hash.modID) && asf.uniqueID.equals(hash.uniqueID))
+                    .filter(asf -> asf.modID.equals(modID) && asf.uniqueID.equals(uniqueID))
                     .findFirst()
                     .orElse(null);
         }
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
index 9a716055..77832369 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
@@ -12,6 +12,7 @@ import ru.bclib.api.dataexchange.handler.DataExchange.AutoSyncID;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 public class RequestFiles extends DataHandler {
 	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "request_files"), RequestFiles::new, false, false);
@@ -55,6 +56,11 @@ public class RequestFiles extends DataHandler {
 	
 	@Override
 	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
-	
+		List<DataExchange.AutoFileSyncEntry> syncEntries = files
+				.stream().map(asid -> DataExchange.AutoFileSyncEntry.findMatching(asid))
+				.filter(e -> e!=null)
+				.collect(Collectors.toList());
+
+		reply(new SendFiles(syncEntries), server);
 	}
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
index ecd7ef23..1e9afbe2 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
@@ -8,22 +8,44 @@ import net.minecraft.server.MinecraftServer;
 import ru.bclib.BCLib;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
+import ru.bclib.util.Pair;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
 
 public class SendFiles extends DataHandler {
 	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "send_files"), SendFiles::new, false, false);
-	
-	public SendFiles() {
+
+	protected List<DataExchange.AutoFileSyncEntry> files;
+	public SendFiles(){
+		this(null);
+	}
+	public SendFiles(List<DataExchange.AutoFileSyncEntry> files) {
 		super(DESCRIPTOR.IDENTIFIER, true);
+		this.files = files;
 	}
 	
 	@Override
 	protected void serializeData(FriendlyByteBuf buf) {
-	
+		List<DataExchange.AutoFileSyncEntry> existingFiles = files.stream().filter(e -> e.fileName.exists()).collect(Collectors.toList());
+		buf.writeInt(existingFiles.size());
+
+		for (DataExchange.AutoFileSyncEntry entry : existingFiles) {
+			entry.serializeContent(buf);
+		}
 	}
 	
 	@Override
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
-	
+		int size = buf.readInt();
+		List<Pair<DataExchange.AutoFileSyncEntry, byte[]>> receivedFiles = new ArrayList<>(size);
+		BCLib.LOGGER.info("Server sent " + size + " Files:");
+		for (int i=0; i<size; i++){
+			Pair<DataExchange.AutoFileSyncEntry, byte[]> p = DataExchange.AutoFileSyncEntry.deserializeContent(buf);
+			receivedFiles.add(p);
+			BCLib.LOGGER.info("    - " + p.first + " (" + p.second.length + " Bytes)");
+		}
 	}
 	
 	@Override

From 391ca845cfc017bd3a2a419f1c4b3137dc55b176 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 22:11:08 +0200
Subject: [PATCH 17/24] Adding more verbose message

---
 .../bclib/api/dataexchange/handler/SendFiles.java   | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
index 1e9afbe2..228a94a6 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
@@ -35,16 +35,21 @@ public class SendFiles extends DataHandler {
 			entry.serializeContent(buf);
 		}
 	}
-	
+
+	private List<Pair<DataExchange.AutoFileSyncEntry, byte[]>> receivedFiles;
 	@Override
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
 		int size = buf.readInt();
-		List<Pair<DataExchange.AutoFileSyncEntry, byte[]>> receivedFiles = new ArrayList<>(size);
+		receivedFiles = new ArrayList<>(size);
 		BCLib.LOGGER.info("Server sent " + size + " Files:");
 		for (int i=0; i<size; i++){
 			Pair<DataExchange.AutoFileSyncEntry, byte[]> p = DataExchange.AutoFileSyncEntry.deserializeContent(buf);
-			receivedFiles.add(p);
-			BCLib.LOGGER.info("    - " + p.first + " (" + p.second.length + " Bytes)");
+			if (p.first != null) {
+				receivedFiles.add(p);
+				BCLib.LOGGER.info("    - " + p.first + " (" + p.second.length + " Bytes)");
+			} else {
+				BCLib.LOGGER.error("    - Failed to receive File");
+			}
 		}
 	}
 	

From c28a566c78c7c89405ed6b9c928ae38e07368573 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 22:26:56 +0200
Subject: [PATCH 18/24] Fixed server crashes

---
 .../ru/bclib/api/dataexchange/DataExchangeAPI.java   | 10 +++++++++-
 .../bclib/api/dataexchange/handler/DataExchange.java | 12 +++++-------
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
index e74a6b92..eccbfa26 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
@@ -29,9 +29,17 @@ public class DataExchangeAPI extends DataExchange {
 	 * You should never need to create a custom instance of this Object.
 	 */
 	public DataExchangeAPI() {
-		super((api) -> new ConnectorClientside(api), (api) -> new ConnectorServerside(api));
+		super();
 	}
 
+	@Environment(EnvType.CLIENT)
+	protected ConnectorClientside clientSupplier(DataExchange api) {
+		return new ConnectorClientside(api);
+	}
+
+	protected ConnectorServerside serverSupplier(DataExchange api) {
+		return new ConnectorServerside(api);
+	}
 
 	/**
 	 * Register a mod to participate in the DataExchange.
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
index a5b0a1d7..9dcf7a7d 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
@@ -182,13 +182,11 @@ abstract public class DataExchange {
     protected final Set<DataHandlerDescriptor> descriptors;
     protected final List<AutoFileSyncEntry> autoSyncFiles = new ArrayList<>(4);
 
-    private final Function<DataExchange, ConnectorClientside> clientSupplier;
-    private final Function<DataExchange, ConnectorServerside> serverSupplier;
+    abstract protected ConnectorClientside clientSupplier(DataExchange api);
+    abstract protected ConnectorServerside serverSupplier(DataExchange api);
 
-    protected DataExchange(Function<DataExchange, ConnectorClientside> client, Function<DataExchange, ConnectorServerside> server){
+    protected DataExchange(){
         descriptors = new HashSet<>();
-        this.clientSupplier = client;
-        this.serverSupplier = server;
     }
 
     public Set<DataHandlerDescriptor> getDescriptors() { return descriptors; }
@@ -196,7 +194,7 @@ abstract public class DataExchange {
     @Environment(EnvType.CLIENT)
     protected void initClientside(){
         if (client!=null) return;
-        client = clientSupplier.apply(this);
+        client = clientSupplier(this);
         ClientLoginConnectionEvents.INIT.register((a, b) ->{
             System.out.println("INIT");
         });
@@ -210,7 +208,7 @@ abstract public class DataExchange {
 
     protected void initServerSide(){
         if (server!=null) return;
-        server = serverSupplier.apply(this);
+        server = serverSupplier(this);
 
         ServerPlayConnectionEvents.INIT.register(server::onPlayInit);
         ServerPlayConnectionEvents.JOIN.register(server::onPlayReady);

From 6883287c720fe4ec06a8667dabbc9c56da79a1ca Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 23:08:13 +0200
Subject: [PATCH 19/24] Finished first draft of File syncing

---
 src/main/java/ru/bclib/BCLib.java             | 14 ++++-
 .../api/dataexchange/DataExchangeAPI.java     | 11 +++-
 .../dataexchange/DataHandlerDescriptor.java   |  4 ++
 .../dataexchange/handler/DataExchange.java    |  7 +--
 .../api/dataexchange/handler/HelloClient.java | 16 ++++--
 .../dataexchange/handler/RequestFiles.java    | 21 +++++++-
 .../api/dataexchange/handler/SendFiles.java   | 53 +++++++++++++++++--
 .../gui/screens/ConfirmRestartScreen.java     | 49 +++++++++++++++++
 .../ru/bclib/gui/screens/SyncFilesScreen.java | 46 ++++++++++++++++
 .../resources/assets/bclib/lang/en_us.json    |  6 ++-
 10 files changed, 209 insertions(+), 18 deletions(-)
 create mode 100644 src/main/java/ru/bclib/gui/screens/ConfirmRestartScreen.java
 create mode 100644 src/main/java/ru/bclib/gui/screens/SyncFilesScreen.java

diff --git a/src/main/java/ru/bclib/BCLib.java b/src/main/java/ru/bclib/BCLib.java
index 7de687de..d284d125 100644
--- a/src/main/java/ru/bclib/BCLib.java
+++ b/src/main/java/ru/bclib/BCLib.java
@@ -7,8 +7,11 @@ import net.minecraft.resources.ResourceLocation;
 import ru.bclib.api.TagAPI;
 import ru.bclib.api.WorldDataAPI;
 import ru.bclib.api.dataexchange.DataExchangeAPI;
+import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.handler.HelloClient;
 import ru.bclib.api.dataexchange.handler.HelloServer;
+import ru.bclib.api.dataexchange.handler.RequestFiles;
+import ru.bclib.api.dataexchange.handler.SendFiles;
 import ru.bclib.config.Configs;
 import ru.bclib.recipes.CraftingRecipes;
 import ru.bclib.registry.BaseBlockEntities;
@@ -16,6 +19,9 @@ import ru.bclib.registry.BaseRegistry;
 import ru.bclib.util.Logger;
 import ru.bclib.world.surface.BCLSurfaceBuilders;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class BCLib implements ModInitializer {
 	public static final String MOD_ID = "bclib";
 	public static final Logger LOGGER = new Logger(MOD_ID);
@@ -30,8 +36,12 @@ public class BCLib implements ModInitializer {
 		WorldDataAPI.registerModCache(MOD_ID);
 		Configs.save();
 		
-		DataExchangeAPI.registerDescriptor(HelloClient.DESCRIPTOR);
-		DataExchangeAPI.registerDescriptor(HelloServer.DESCRIPTOR);
+		DataExchangeAPI.registerDescriptors(List.of(
+				HelloClient.DESCRIPTOR,
+				HelloServer.DESCRIPTOR,
+				RequestFiles.DESCRIPTOR,
+				SendFiles.DESCRIPTOR
+		));
 	}
 	
 	public static boolean isDevEnvironment() {
diff --git a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
index eccbfa26..e13faa0a 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
@@ -59,7 +59,7 @@ public class DataExchangeAPI extends DataExchange {
 	}
 	
 	/**
-	 * Add a new Descriptor for a DataHandler.
+	 * Add a new Descriptor for a {@link DataHandler}.
 	 * @param desc The Descriptor you want to add.
 	 */
 	public static void registerDescriptor(DataHandlerDescriptor desc){
@@ -67,6 +67,15 @@ public class DataExchangeAPI extends DataExchange {
 		api.getDescriptors().add(desc);
 	}
 
+	/**
+	 * Bulk-Add a Descriptors for your {@link DataHandler}-Objects.
+	 * @param desc The Descriptors you want to add.
+	 */
+	public static void registerDescriptors(List<DataHandlerDescriptor> desc){
+		DataExchange api = DataExchange.getInstance();
+		api.getDescriptors().addAll(desc);
+	}
+
 	/**
 	 * Sends the Handler.
 	 * <p>
diff --git a/src/main/java/ru/bclib/api/dataexchange/DataHandlerDescriptor.java b/src/main/java/ru/bclib/api/dataexchange/DataHandlerDescriptor.java
index 99017fe4..61860185 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataHandlerDescriptor.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataHandlerDescriptor.java
@@ -1,6 +1,10 @@
 package ru.bclib.api.dataexchange;
 
 import net.minecraft.resources.ResourceLocation;
+import ru.bclib.api.dataexchange.handler.HelloClient;
+import ru.bclib.api.dataexchange.handler.HelloServer;
+import ru.bclib.api.dataexchange.handler.RequestFiles;
+import ru.bclib.api.dataexchange.handler.SendFiles;
 
 import java.util.function.Supplier;
 
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
index 9dcf7a7d..9e4e66a9 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
@@ -97,10 +97,10 @@ abstract public class DataExchange {
             return new byte[0];
         }
 
-        public void serializeContent(FriendlyByteBuf buf){
+        public int serializeContent(FriendlyByteBuf buf){
             DataHandler.writeString(buf, modID);
             DataHandler.writeString(buf, uniqueID);
-            serializeFileContent(buf);
+            return serializeFileContent(buf);
         }
         public static Pair<AutoFileSyncEntry, byte[]> deserializeContent(FriendlyByteBuf buf){
             final String modID = DataHandler.readString(buf);
@@ -138,10 +138,11 @@ abstract public class DataExchange {
             return new Pair(hash, data);
         }
 
-        private void serializeFileContent(FriendlyByteBuf buf) {
+        private int serializeFileContent(FriendlyByteBuf buf) {
             byte[] content = getContent();
             buf.writeInt(content.length);
             buf.writeByteArray(content);
+            return content.length;
         }
 
         private static byte[] deserializeFileContent(FriendlyByteBuf buf) {
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index 05176c16..73e50045 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -16,6 +16,7 @@ import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
 import ru.bclib.api.dataexchange.handler.DataExchange.AutoSyncID;
 import ru.bclib.api.datafixer.DataFixerAPI;
+import ru.bclib.gui.screens.SyncFilesScreen;
 import ru.bclib.gui.screens.WarnBCLibVersionMismatch;
 
 import java.util.ArrayList;
@@ -134,8 +135,10 @@ public class HelloClient extends DataHandler {
 			
 			BCLib.LOGGER.info("    - " + e + ": " + (willRequest ? " (requesting)":""));
 		}
+
 		if (filesToRequest.size()>0) {
 			showDonwloadConfigs(client, filesToRequest);
+			return;
 		}
 	}
 	
@@ -154,9 +157,13 @@ public class HelloClient extends DataHandler {
 	
 	@Environment(EnvType.CLIENT)
 	protected void showDonwloadConfigs(Minecraft client, List<AutoSyncID> files){
-		requestFileDownloads((hadErrors)->{
-			client.stop();
-		}, files);
+		client.setScreen(new SyncFilesScreen((download) -> {
+			Minecraft.getInstance().setScreen((Screen)null);
+			if (download){
+				requestFileDownloads(files);
+			}
+		}));
+
 	}
 	
 	private void requestBCLibDownload(Consumer<Boolean> whenFinished){
@@ -164,9 +171,8 @@ public class HelloClient extends DataHandler {
 		whenFinished.accept(true);
 	}
 	
-	private void requestFileDownloads(Consumer<Boolean> whenFinished, List<AutoSyncID> files){
+	private void requestFileDownloads(List<AutoSyncID> files){
 		BCLib.LOGGER.info("Starting download of Files:" + files.size());
 		DataExchangeAPI.send(new RequestFiles(files));
-		whenFinished.accept(true);
 	}
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
index 77832369..5c584780 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
@@ -12,10 +12,12 @@ import ru.bclib.api.dataexchange.handler.DataExchange.AutoSyncID;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.UUID;
 import java.util.stream.Collectors;
 
 public class RequestFiles extends DataHandler {
 	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "request_files"), RequestFiles::new, false, false);
+	static String currentToken = "";
 	
 	protected List<AutoSyncID> files;
 	private RequestFiles(){
@@ -29,6 +31,9 @@ public class RequestFiles extends DataHandler {
 	
 	@Override
 	protected void serializeData(FriendlyByteBuf buf) {
+		newToken();
+		writeString(buf, currentToken);
+
 		buf.writeInt(files.size());
 		
 		for (AutoSyncID a : files){
@@ -36,9 +41,11 @@ public class RequestFiles extends DataHandler {
 			writeString(buf, a.getUniqueID());
 		}
 	}
-	
+
+	String receivedToken = "";
 	@Override
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
+		receivedToken = readString(buf);
 		int size = buf.readInt();
 		files = new ArrayList<>(size);
 		
@@ -61,6 +68,16 @@ public class RequestFiles extends DataHandler {
 				.filter(e -> e!=null)
 				.collect(Collectors.toList());
 
-		reply(new SendFiles(syncEntries), server);
+		reply(new SendFiles(syncEntries, receivedToken), server);
+	}
+
+
+
+	public static void newToken(){
+		currentToken =  UUID.randomUUID().toString();
+	}
+
+	static {
+		newToken();
 	}
 }
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
index 228a94a6..c7bb084c 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
@@ -1,44 +1,67 @@
 package ru.bclib.api.dataexchange.handler;
 
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
 import net.fabricmc.fabric.api.networking.v1.PacketSender;
 import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.screens.Screen;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
 import ru.bclib.BCLib;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
+import ru.bclib.gui.screens.ConfirmRestartScreen;
+import ru.bclib.gui.screens.SyncFilesScreen;
 import ru.bclib.util.Pair;
 
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.OpenOption;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.UUID;
 import java.util.stream.Collectors;
 
 public class SendFiles extends DataHandler {
 	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "send_files"), SendFiles::new, false, false);
 
 	protected List<DataExchange.AutoFileSyncEntry> files;
+	private String token = "";
 	public SendFiles(){
-		this(null);
+		this(null, "");
 	}
-	public SendFiles(List<DataExchange.AutoFileSyncEntry> files) {
+	public SendFiles(List<DataExchange.AutoFileSyncEntry> files, String token) {
 		super(DESCRIPTOR.IDENTIFIER, true);
 		this.files = files;
+		this.token = token;
 	}
 	
 	@Override
 	protected void serializeData(FriendlyByteBuf buf) {
 		List<DataExchange.AutoFileSyncEntry> existingFiles = files.stream().filter(e -> e.fileName.exists()).collect(Collectors.toList());
+		writeString(buf, token);
 		buf.writeInt(existingFiles.size());
 
+		BCLib.LOGGER.info("Sending " + existingFiles.size() + " Files to Client:");
 		for (DataExchange.AutoFileSyncEntry entry : existingFiles) {
-			entry.serializeContent(buf);
+			int length = entry.serializeContent(buf);
+			BCLib.LOGGER.info("    - " + entry + " (" + length + " Bytes)");
 		}
 	}
 
 	private List<Pair<DataExchange.AutoFileSyncEntry, byte[]>> receivedFiles;
 	@Override
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
+		token = readString(buf);
+		if (!token.equals(RequestFiles.currentToken)) {
+			BCLib.LOGGER.error("Unrequested File Transfer!");
+			receivedFiles = new ArrayList<>(0);
+			return;
+		}
+
 		int size = buf.readInt();
 		receivedFiles = new ArrayList<>(size);
 		BCLib.LOGGER.info("Server sent " + size + " Files:");
@@ -55,6 +78,28 @@ public class SendFiles extends DataHandler {
 	
 	@Override
 	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
-	
+		BCLib.LOGGER.info("Writing Files:");
+		for (Pair<DataExchange.AutoFileSyncEntry, byte[]> entry : receivedFiles) {
+			final DataExchange.AutoFileSyncEntry e = entry.first;
+			final byte[] data = entry.second;
+			Path path = e.fileName.toPath();
+			BCLib.LOGGER.info("    - Writing " + path + " (" + data.length + " Bytes)");
+			try {
+				Files.write(path, data);
+			} catch (IOException ioException) {
+				BCLib.LOGGER.error("    --> Writing "+e.fileName+" failed: " + ioException);
+			}
+		}
+
+		showConfirmRestart(client);
+	}
+
+	@Environment(EnvType.CLIENT)
+	protected void showConfirmRestart(Minecraft client){
+		client.setScreen(new ConfirmRestartScreen(() -> {
+			Minecraft.getInstance().setScreen((Screen)null);
+			client.stop();
+		}));
+
 	}
 }
diff --git a/src/main/java/ru/bclib/gui/screens/ConfirmRestartScreen.java b/src/main/java/ru/bclib/gui/screens/ConfirmRestartScreen.java
new file mode 100644
index 00000000..09c12cbf
--- /dev/null
+++ b/src/main/java/ru/bclib/gui/screens/ConfirmRestartScreen.java
@@ -0,0 +1,49 @@
+package ru.bclib.gui.screens;
+
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
+import net.minecraft.network.chat.CommonComponents;
+import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.TranslatableComponent;
+import ru.bclib.gui.GridScreen;
+
+
+@Environment(EnvType.CLIENT)
+public class ConfirmRestartScreen extends GridScreen {
+    private final Component description;
+    private final ConfirmRestartScreen.Listener listener;
+
+    public ConfirmRestartScreen(ConfirmRestartScreen.Listener listener) {
+        this(listener, null);
+    }
+
+    public ConfirmRestartScreen(ConfirmRestartScreen.Listener listener, Component message) {
+        super(30, new TranslatableComponent("bclib.datafixer.confirmrestart.title"));
+
+        this.description = message==null?new TranslatableComponent("bclib.datafixer.confirmrestart.message"):message;
+        this.listener = listener;
+    }
+
+    protected void initLayout() {
+        final int BUTTON_HEIGHT = 20;
+
+        grid.addMessageRow(this.description, 25);
+
+        grid.startRow();
+        grid.addButton( BUTTON_HEIGHT, CommonComponents.GUI_PROCEED, (button) -> {
+            listener.proceed();
+        });
+
+        grid.endRow();
+        grid.recenterVertically();
+    }
+
+    public boolean shouldCloseOnEsc() {
+        return false;
+    }
+
+    @Environment(EnvType.CLIENT)
+    public interface Listener {
+        void proceed();
+    }
+}
diff --git a/src/main/java/ru/bclib/gui/screens/SyncFilesScreen.java b/src/main/java/ru/bclib/gui/screens/SyncFilesScreen.java
new file mode 100644
index 00000000..11505bf4
--- /dev/null
+++ b/src/main/java/ru/bclib/gui/screens/SyncFilesScreen.java
@@ -0,0 +1,46 @@
+package ru.bclib.gui.screens;
+
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
+import net.minecraft.network.chat.CommonComponents;
+import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.TranslatableComponent;
+import ru.bclib.gui.GridScreen;
+
+@Environment(EnvType.CLIENT)
+public class SyncFilesScreen extends GridScreen {
+    private final Component description;
+    private final SyncFilesScreen.Listener listener;
+    public SyncFilesScreen(SyncFilesScreen.Listener listener) {
+        super(30, new TranslatableComponent("bclib.datafixer.syncfiles.title"));
+
+        this.description = new TranslatableComponent("bclib.datafixer.syncfiles.message");
+        this.listener = listener;
+    }
+
+    protected void initLayout() {
+        final int BUTTON_HEIGHT = 20;
+
+        grid.addMessageRow(this.description, 25);
+
+        grid.startRow();
+        grid.addButton( BUTTON_HEIGHT, CommonComponents.GUI_NO, (button) -> {
+            listener.proceed(false);
+        });
+        grid.addButton( BUTTON_HEIGHT, CommonComponents.GUI_YES, (button) -> {
+            listener.proceed(true);
+        });
+
+        grid.endRow();
+        grid.recenterVertically();
+    }
+
+    public boolean shouldCloseOnEsc() {
+        return false;
+    }
+
+    @Environment(EnvType.CLIENT)
+    public interface Listener {
+        void proceed(boolean download);
+    }
+}
diff --git a/src/main/resources/assets/bclib/lang/en_us.json b/src/main/resources/assets/bclib/lang/en_us.json
index c4c8b0ec..09d1436f 100644
--- a/src/main/resources/assets/bclib/lang/en_us.json
+++ b/src/main/resources/assets/bclib/lang/en_us.json
@@ -6,5 +6,9 @@
 	"bclib.datafixer.backupWarning.nofixes": "Continue Without Fixes",
 	"bclib.datafixer.backupWarning.continue": "Continue Without Backup",
 	"bclib.datafixer.bclibmissmatch.title": "Version Mismatch",
-	"bclib.datafixer.bclibmissmatch.message": "The Version of BCLib on the server and this client do not match. This will cause problems when playing.\n\nDo you want to automatically download the BCLib-Version from the server. You will need to delete the old version from your Mods Directory and restart the game."
+	"bclib.datafixer.bclibmissmatch.message": "The Version of BCLib on the server and this client do not match. This will cause problems when playing.\n\nDo you want to automatically download the BCLib-Version from the server. You will need to delete the old version from your Mods Directory and restart the game.",
+	"bclib.datafixer.syncfiles.title": "Mismatching (Config-)Files",
+	"bclib.datafixer.syncfiles.message": "Some Files on the Server doe not match the versions on the client.\n\nDo you want to replace the local versions with the ones from the server?",
+	"bclib.datafixer.confirmrestart.title": "Restart Required",
+	"bclib.datafixer.confirmrestart.message": "The requested files were processed. You need o restart Minecraft now."
 }
\ No newline at end of file

From 3438c86de2e4d9e7cf2dd3c35d8a5f6fa0f533a2 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 23:20:39 +0200
Subject: [PATCH 20/24] Refactor

---
 .../ru/bclib/api/dataexchange/FileHash.java   |  22 +--
 .../handler/AutoFileSyncEntry.java            | 123 +++++++++++++
 .../dataexchange/handler/DataExchange.java    | 164 ++++--------------
 .../api/dataexchange/handler/HelloClient.java |  12 +-
 .../dataexchange/handler/RequestFiles.java    |  10 +-
 .../api/dataexchange/handler/SendFiles.java   |  20 +--
 6 files changed, 182 insertions(+), 169 deletions(-)
 create mode 100644 src/main/java/ru/bclib/api/dataexchange/handler/AutoFileSyncEntry.java

diff --git a/src/main/java/ru/bclib/api/dataexchange/FileHash.java b/src/main/java/ru/bclib/api/dataexchange/FileHash.java
index 44296b85..848a9104 100644
--- a/src/main/java/ru/bclib/api/dataexchange/FileHash.java
+++ b/src/main/java/ru/bclib/api/dataexchange/FileHash.java
@@ -23,7 +23,7 @@ import java.util.function.Predicate;
  * You can compare instances using {@link #equals(Object)} to determine if two files are
  * identical.
  */
-public class FileHash {
+public class FileHash extends DataExchange.AutoSyncID {
     /**
      * The md5-hash of the file
      */
@@ -40,35 +40,19 @@ public class FileHash {
      */
     public final int value;
 
-    /**
-     * A Unique ID for the referenced File.
-     * <p>
-     * Files with the same {@link #modID} need to have a unique IDs. Normally the filename from {@link #FileHash(String, File, byte[], int, int)}
-     * is used to generated that ID, but you can directly specify one using {@link #FileHash(String, String, byte[], int, int)}.
-     */
-    @NotNull
-    public final String uniqueID;
 
-    /**
-     * The ID of the Mod that is registering the File
-     */
-    @NotNull
-    public final String modID;
 
     FileHash(String modID, File file, byte[] md5, int size, int value) {
         this(modID, file.getName(), md5, size, value);
     }
 
     FileHash(String modID, String uniqueID, byte[] md5, int size, int value) {
-        Objects.nonNull(modID);
-        Objects.nonNull(uniqueID);
+        super(modID, uniqueID);
         Objects.nonNull(md5);
 
         this.md5 = md5;
         this.size = size;
         this.value = value;
-        this.modID = modID;
-        this.uniqueID = uniqueID;
     }
 
     private static int ERR_DOES_NOT_EXIST = -10;
@@ -85,7 +69,7 @@ public class FileHash {
 
     @Override
     public String toString() {
-        return String.format("%08x", size)
+        return super.toString()+": "+String.format("%08x", size)
             + "-"
             + String.format("%08x", value)
             + "-"
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/AutoFileSyncEntry.java b/src/main/java/ru/bclib/api/dataexchange/handler/AutoFileSyncEntry.java
new file mode 100644
index 00000000..8ac37878
--- /dev/null
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/AutoFileSyncEntry.java
@@ -0,0 +1,123 @@
+package ru.bclib.api.dataexchange.handler;
+
+import net.minecraft.network.FriendlyByteBuf;
+import ru.bclib.api.dataexchange.DataHandler;
+import ru.bclib.api.dataexchange.FileHash;
+import ru.bclib.util.Pair;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+class AutoFileSyncEntry extends DataExchange.AutoSyncID {
+    public final DataExchange.NeedTransferPredicate needTransfer;
+    public final File fileName;
+    public final boolean requestContent;
+    private FileHash hash;
+
+    AutoFileSyncEntry(String modID, File fileName, boolean requestContent, DataExchange.NeedTransferPredicate needTransfer) {
+        this(modID, fileName.getName(), fileName, requestContent, needTransfer);
+    }
+
+    AutoFileSyncEntry(String modID, String uniqueID, File fileName, boolean requestContent, DataExchange.NeedTransferPredicate needTransfer) {
+        super(modID, uniqueID);
+        this.needTransfer = needTransfer;
+        this.fileName = fileName;
+        this.requestContent = requestContent;
+    }
+
+    public FileHash getFileHash() {
+        if (hash == null)
+        {
+            hash = FileHash.create(modID, fileName, uniqueID);
+        }
+        return hash;
+    }
+
+    public byte[] getContent() {
+        if (!fileName.exists()) return new byte[0];
+        final Path path = fileName.toPath();
+
+        try {
+            return Files.readAllBytes(path);
+        } catch (IOException e) {
+
+        }
+        return new byte[0];
+    }
+
+    public int serializeContent(FriendlyByteBuf buf) {
+        DataHandler.writeString(buf, modID);
+        DataHandler.writeString(buf, uniqueID);
+        return serializeFileContent(buf);
+    }
+
+    public static Pair<AutoFileSyncEntry, byte[]> deserializeContent(FriendlyByteBuf buf) {
+        final String modID = DataHandler.readString(buf);
+        final String uniqueID = DataHandler.readString(buf);
+        byte[] data = deserializeFileContent(buf);
+
+        AutoFileSyncEntry entry = AutoFileSyncEntry.findMatching(modID, uniqueID);
+        return new Pair<>(entry, data);
+    }
+
+
+    public void serialize(FriendlyByteBuf buf) {
+        getFileHash().serialize(buf);
+        buf.writeBoolean(requestContent);
+
+        if (requestContent) {
+            serializeFileContent(buf);
+        }
+    }
+
+    public static DataExchange.AutoSyncTriple deserializeAndMatch(FriendlyByteBuf buf) {
+        Pair<FileHash, byte[]> e = deserialize(buf);
+        AutoFileSyncEntry match = findMatching(e.first);
+        return new DataExchange.AutoSyncTriple(e.first, e.second, match);
+    }
+
+    public static Pair<FileHash, byte[]> deserialize(FriendlyByteBuf buf) {
+        FileHash hash = FileHash.deserialize(buf);
+        boolean withContent = buf.readBoolean();
+        byte[] data = null;
+        if (withContent) {
+            data = deserializeFileContent(buf);
+        }
+
+        return new Pair(hash, data);
+    }
+
+    private int serializeFileContent(FriendlyByteBuf buf) {
+        byte[] content = getContent();
+        buf.writeInt(content.length);
+        buf.writeByteArray(content);
+        return content.length;
+    }
+
+    private static byte[] deserializeFileContent(FriendlyByteBuf buf) {
+        byte[] data;
+        int size = buf.readInt();
+        data = buf.readByteArray(size);
+        return data;
+    }
+
+    public static AutoFileSyncEntry findMatching(FileHash hash) {
+        return findMatching(hash.modID, hash.uniqueID);
+    }
+
+    public static AutoFileSyncEntry findMatching(DataExchange.AutoSyncID aid) {
+        return findMatching(aid.modID, aid.uniqueID);
+    }
+
+    public static AutoFileSyncEntry findMatching(String modID, String uniqueID) {
+        return DataExchange
+                .getInstance()
+                .autoSyncFiles
+                .stream()
+                .filter(asf -> asf.modID.equals(modID) && asf.uniqueID.equals(uniqueID))
+                .findFirst()
+                .orElse(null);
+    }
+}
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
index 9e4e66a9..3db0c347 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/DataExchange.java
@@ -5,7 +5,7 @@ import net.fabricmc.api.Environment;
 import net.fabricmc.fabric.api.client.networking.v1.ClientLoginConnectionEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
-import net.minecraft.network.FriendlyByteBuf;
+import org.jetbrains.annotations.NotNull;
 import ru.bclib.api.dataexchange.ConnectorClientside;
 import ru.bclib.api.dataexchange.ConnectorServerside;
 import ru.bclib.api.dataexchange.DataExchangeAPI;
@@ -16,17 +16,11 @@ import ru.bclib.util.Pair;
 import ru.bclib.util.Triple;
 
 import java.io.File;
-import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
-import java.util.function.BiFunction;
-import java.util.function.Function;
-import java.util.function.Predicate;
 
 abstract public class DataExchange {
     @FunctionalInterface
@@ -34,21 +28,50 @@ abstract public class DataExchange {
         public boolean test(FileHash clientHash, FileHash serverHash, byte[] content);
     }
     
-    final static class AutoSyncID extends Pair<String, String>{
+    public static class AutoSyncID {
+        /**
+         * A Unique ID for the referenced File.
+         * <p>
+         * Files with the same {@link #modID} need to have a unique IDs. Normally the filename from {@link #FileHash(String, File, byte[], int, int)}
+         * is used to generated that ID, but you can directly specify one using {@link #FileHash(String, String, byte[], int, int)}.
+         */
+        @NotNull
+        public final String uniqueID;
+
+        /**
+         * The ID of the Mod that is registering the File
+         */
+        @NotNull
+        public final String modID;
+
         public AutoSyncID(String modID, String uniqueID) {
-            super(modID, uniqueID);
+            Objects.nonNull(modID);
+            Objects.nonNull(uniqueID);
+
+            this.modID = modID;
+            this.uniqueID = uniqueID;
         }
-        
-        public String getModID() { return this.first; }
-        public String getUniqueID() { return this.second; }
     
         @Override
         public String toString() {
-            return first+"."+second;
+            return modID+"."+uniqueID;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            AutoSyncID that = (AutoSyncID) o;
+            return uniqueID.equals(that.uniqueID) && modID.equals(that.modID);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(uniqueID, modID);
         }
     }
 
-    final static class AutoSyncTriple extends Triple<FileHash, byte[], DataExchange.AutoFileSyncEntry>{
+    final static class AutoSyncTriple extends Triple<FileHash, byte[], AutoFileSyncEntry>{
         public AutoSyncTriple(FileHash first, byte[] second, AutoFileSyncEntry third) {
             super(first, second, third);
         }
@@ -58,117 +81,6 @@ abstract public class DataExchange {
             return first.modID+"."+first.uniqueID;
         }
     }
-    static class AutoFileSyncEntry {
-        public final NeedTransferPredicate needTransfer;
-        public final File fileName;
-        public final String modID;
-        public final String uniqueID;
-        public final boolean requestContent;
-        private FileHash hash;
-
-        AutoFileSyncEntry(String modID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer) {
-            this(modID, fileName.getName(), fileName, requestContent, needTransfer);
-        }
-
-        AutoFileSyncEntry(String modID, String uniqueID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer) {
-            this.needTransfer = needTransfer;
-            this.fileName = fileName;
-            this.modID = modID;
-            this.uniqueID = uniqueID;
-            this.requestContent = requestContent;
-        }
-
-        public FileHash getFileHash(){
-            if (hash == null) {
-                hash = FileHash.create(modID, fileName, uniqueID);
-            }
-            return hash;
-        }
-
-        public byte[] getContent(){
-            if (!fileName.exists()) return new byte[0];
-            final Path path = fileName.toPath();
-
-            try {
-                return Files.readAllBytes(path);
-            } catch (IOException e) {
-
-            }
-            return new byte[0];
-        }
-
-        public int serializeContent(FriendlyByteBuf buf){
-            DataHandler.writeString(buf, modID);
-            DataHandler.writeString(buf, uniqueID);
-            return serializeFileContent(buf);
-        }
-        public static Pair<AutoFileSyncEntry, byte[]> deserializeContent(FriendlyByteBuf buf){
-            final String modID = DataHandler.readString(buf);
-            final String uniqueID = DataHandler.readString(buf);
-            byte[] data = deserializeFileContent(buf);
-
-            AutoFileSyncEntry entry = AutoFileSyncEntry.findMatching(modID, uniqueID);
-            return new Pair<>(entry, data);
-        }
-
-        
-        public void serialize(FriendlyByteBuf buf){
-            getFileHash().serialize(buf);
-            buf.writeBoolean(requestContent);
-
-            if (requestContent) {
-                serializeFileContent(buf);
-            }
-        }
-
-        public static AutoSyncTriple deserializeAndMatch(FriendlyByteBuf buf){
-            Pair<FileHash, byte[]> e = deserialize(buf);
-            AutoFileSyncEntry match = findMatching(e.first);
-            return new AutoSyncTriple(e.first, e.second, match);
-        }
-
-        public static Pair<FileHash, byte[]> deserialize(FriendlyByteBuf buf){
-            FileHash hash = FileHash.deserialize(buf);
-            boolean withContent = buf.readBoolean();
-            byte[] data = null;
-            if (withContent) {
-                data = deserializeFileContent(buf);
-            }
-
-            return new Pair(hash, data);
-        }
-
-        private int serializeFileContent(FriendlyByteBuf buf) {
-            byte[] content = getContent();
-            buf.writeInt(content.length);
-            buf.writeByteArray(content);
-            return content.length;
-        }
-
-        private static byte[] deserializeFileContent(FriendlyByteBuf buf) {
-            byte[] data;
-            int size = buf.readInt();
-            data = buf.readByteArray(size);
-            return data;
-        }
-
-        public static AutoFileSyncEntry findMatching(FileHash hash){
-            return findMatching(hash.modID, hash.uniqueID);
-        }
-        public static AutoFileSyncEntry findMatching(AutoSyncID aid){
-            return findMatching(aid.getModID(), aid.getUniqueID());
-        }
-
-        public static AutoFileSyncEntry findMatching(String modID, String uniqueID){
-            return DataExchange
-                    .getInstance()
-                    .autoSyncFiles
-                    .stream()
-                    .filter(asf -> asf.modID.equals(modID) && asf.uniqueID.equals(uniqueID))
-                    .findFirst()
-                    .orElse(null);
-        }
-    }
 
     private static DataExchangeAPI instance;
     protected static DataExchangeAPI getInstance(){
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index 73e50045..d6a840dd 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -67,10 +67,10 @@ public class HelloClient extends DataHandler {
 		}
 
 		//send config Data
-		final List<DataExchange.AutoFileSyncEntry> autoSyncFiles = DataExchange.getInstance().autoSyncFiles;
+		final List<AutoFileSyncEntry> autoSyncFiles = DataExchange.getInstance().autoSyncFiles;
 		buf.writeInt(autoSyncFiles.size());
-		for (DataExchange.AutoFileSyncEntry entry : autoSyncFiles) {
-			System.out.println("Serializing " + entry.getFileHash());
+		for (AutoFileSyncEntry entry : autoSyncFiles) {
+			//System.out.println("Serializing " + entry.getFileHash());
 			entry.serialize(buf);
 		}
 	}
@@ -96,10 +96,10 @@ public class HelloClient extends DataHandler {
 		count = buf.readInt();
 		autoSyncedFiles = new ArrayList<>(count);
 		for (int i=0; i< count; i++) {
-			System.out.println("Deserializing ");
-			DataExchange.AutoSyncTriple t = DataExchange.AutoFileSyncEntry.deserializeAndMatch(buf);
+			//System.out.println("Deserializing ");
+			DataExchange.AutoSyncTriple t = AutoFileSyncEntry.deserializeAndMatch(buf);
 			autoSyncedFiles.add(t);
-			System.out.println(t.first);
+			//System.out.println(t.first);
 		}
 	}
 	
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
index 5c584780..7a2430d2 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/RequestFiles.java
@@ -37,8 +37,8 @@ public class RequestFiles extends DataHandler {
 		buf.writeInt(files.size());
 		
 		for (AutoSyncID a : files){
-			writeString(buf, a.getModID());
-			writeString(buf, a.getUniqueID());
+			writeString(buf, a.modID);
+			writeString(buf, a.uniqueID);
 		}
 	}
 
@@ -63,16 +63,14 @@ public class RequestFiles extends DataHandler {
 	
 	@Override
 	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
-		List<DataExchange.AutoFileSyncEntry> syncEntries = files
-				.stream().map(asid -> DataExchange.AutoFileSyncEntry.findMatching(asid))
+		List<AutoFileSyncEntry> syncEntries = files
+				.stream().map(asid -> AutoFileSyncEntry.findMatching(asid))
 				.filter(e -> e!=null)
 				.collect(Collectors.toList());
 
 		reply(new SendFiles(syncEntries, receivedToken), server);
 	}
 
-
-
 	public static void newToken(){
 		currentToken =  UUID.randomUUID().toString();
 	}
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
index c7bb084c..df74449e 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
@@ -12,28 +12,24 @@ import ru.bclib.BCLib;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
 import ru.bclib.gui.screens.ConfirmRestartScreen;
-import ru.bclib.gui.screens.SyncFilesScreen;
 import ru.bclib.util.Pair;
 
 import java.io.IOException;
 import java.nio.file.Files;
-import java.nio.file.OpenOption;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.UUID;
 import java.util.stream.Collectors;
 
 public class SendFiles extends DataHandler {
 	public static DataHandlerDescriptor DESCRIPTOR = new DataHandlerDescriptor(new ResourceLocation(BCLib.MOD_ID, "send_files"), SendFiles::new, false, false);
 
-	protected List<DataExchange.AutoFileSyncEntry> files;
+	protected List<AutoFileSyncEntry> files;
 	private String token = "";
 	public SendFiles(){
 		this(null, "");
 	}
-	public SendFiles(List<DataExchange.AutoFileSyncEntry> files, String token) {
+	public SendFiles(List<AutoFileSyncEntry> files, String token) {
 		super(DESCRIPTOR.IDENTIFIER, true);
 		this.files = files;
 		this.token = token;
@@ -41,18 +37,18 @@ public class SendFiles extends DataHandler {
 	
 	@Override
 	protected void serializeData(FriendlyByteBuf buf) {
-		List<DataExchange.AutoFileSyncEntry> existingFiles = files.stream().filter(e -> e.fileName.exists()).collect(Collectors.toList());
+		List<AutoFileSyncEntry> existingFiles = files.stream().filter(e -> e.fileName.exists()).collect(Collectors.toList());
 		writeString(buf, token);
 		buf.writeInt(existingFiles.size());
 
 		BCLib.LOGGER.info("Sending " + existingFiles.size() + " Files to Client:");
-		for (DataExchange.AutoFileSyncEntry entry : existingFiles) {
+		for (AutoFileSyncEntry entry : existingFiles) {
 			int length = entry.serializeContent(buf);
 			BCLib.LOGGER.info("    - " + entry + " (" + length + " Bytes)");
 		}
 	}
 
-	private List<Pair<DataExchange.AutoFileSyncEntry, byte[]>> receivedFiles;
+	private List<Pair<AutoFileSyncEntry, byte[]>> receivedFiles;
 	@Override
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
 		token = readString(buf);
@@ -66,7 +62,7 @@ public class SendFiles extends DataHandler {
 		receivedFiles = new ArrayList<>(size);
 		BCLib.LOGGER.info("Server sent " + size + " Files:");
 		for (int i=0; i<size; i++){
-			Pair<DataExchange.AutoFileSyncEntry, byte[]> p = DataExchange.AutoFileSyncEntry.deserializeContent(buf);
+			Pair<AutoFileSyncEntry, byte[]> p = AutoFileSyncEntry.deserializeContent(buf);
 			if (p.first != null) {
 				receivedFiles.add(p);
 				BCLib.LOGGER.info("    - " + p.first + " (" + p.second.length + " Bytes)");
@@ -79,8 +75,8 @@ public class SendFiles extends DataHandler {
 	@Override
 	protected void runOnGameThread(Minecraft client, MinecraftServer server, boolean isClient) {
 		BCLib.LOGGER.info("Writing Files:");
-		for (Pair<DataExchange.AutoFileSyncEntry, byte[]> entry : receivedFiles) {
-			final DataExchange.AutoFileSyncEntry e = entry.first;
+		for (Pair<AutoFileSyncEntry, byte[]> entry : receivedFiles) {
+			final AutoFileSyncEntry e = entry.first;
 			final byte[] data = entry.second;
 			Path path = e.fileName.toPath();
 			BCLib.LOGGER.info("    - Writing " + path + " (" + data.length + " Bytes)");

From 4d3f7aa34bb93630e4e820051ab79bb3a145eda6 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 23:29:41 +0200
Subject: [PATCH 21/24] Api cleanup

---
 .../api/dataexchange/DataExchangeAPI.java     | 245 +++++++++---------
 1 file changed, 127 insertions(+), 118 deletions(-)

diff --git a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
index e13faa0a..e6029146 100644
--- a/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
+++ b/src/main/java/ru/bclib/api/dataexchange/DataExchangeAPI.java
@@ -23,132 +23,141 @@ import java.util.function.Function;
 import java.util.function.Predicate;
 
 public class DataExchangeAPI extends DataExchange {
-	private final static List<String> MODS = Lists.newArrayList();
+    private final static List<String> MODS = Lists.newArrayList();
 
-	/**
-	 * You should never need to create a custom instance of this Object.
-	 */
-	public DataExchangeAPI() {
-		super();
-	}
+    /**
+     * You should never need to create a custom instance of this Object.
+     */
+    public DataExchangeAPI() {
+        super();
+    }
 
-	@Environment(EnvType.CLIENT)
-	protected ConnectorClientside clientSupplier(DataExchange api) {
-		return new ConnectorClientside(api);
-	}
+    @Environment(EnvType.CLIENT)
+    protected ConnectorClientside clientSupplier(DataExchange api) {
+        return new ConnectorClientside(api);
+    }
 
-	protected ConnectorServerside serverSupplier(DataExchange api) {
-		return new ConnectorServerside(api);
-	}
+    protected ConnectorServerside serverSupplier(DataExchange api) {
+        return new ConnectorServerside(api);
+    }
 
-	/**
-	 * Register a mod to participate in the DataExchange.
-	 *
-	 * @param modID - {@link String} modID.
-	 */
-	public static void registerMod(String modID) {
-		MODS.add(modID);
-	}
-	
-	/**
-	 * Returns the IDs of all registered Mods.
-	 * @return List of modIDs
-	 */
-	public static List<String> registeredMods(){
-		return MODS;
-	}
-	
-	/**
-	 * Add a new Descriptor for a {@link DataHandler}.
-	 * @param desc The Descriptor you want to add.
-	 */
-	public static void registerDescriptor(DataHandlerDescriptor desc){
-		DataExchange api = DataExchange.getInstance();
-		api.getDescriptors().add(desc);
-	}
+    /**
+     * Register a mod to participate in the DataExchange.
+     *
+     * @param modID - {@link String} modID.
+     */
+    public static void registerMod(String modID) {
+        MODS.add(modID);
+    }
 
-	/**
-	 * Bulk-Add a Descriptors for your {@link DataHandler}-Objects.
-	 * @param desc The Descriptors you want to add.
-	 */
-	public static void registerDescriptors(List<DataHandlerDescriptor> desc){
-		DataExchange api = DataExchange.getInstance();
-		api.getDescriptors().addAll(desc);
-	}
+    /**
+     * Returns the IDs of all registered Mods.
+     *
+     * @return List of modIDs
+     */
+    public static List<String> registeredMods() {
+        return MODS;
+    }
 
-	/**
-	 * Sends the Handler.
-	 * <p>
-	 * Depending on what the result of {@link DataHandler#getOriginatesOnServer()}, the Data is sent from the server
-	 * to the client (if {@code true}) or the other way around.
-	 * <p>
-	 * The method {@link DataHandler#serializeData(FriendlyByteBuf)} is called just before the data is sent. You should
-	 * use this method to add the Data you need to the communication.
-	 * @param h The Data that you want to send
-	 */
-	public static void send(DataHandler h){
-		if (h.getOriginatesOnServer()){
-			DataExchangeAPI.getInstance().server.sendToClient(h);
-		} else {
-			DataExchangeAPI.getInstance().client.sendToServer(h);
-		}
-	}
+    /**
+     * Add a new Descriptor for a {@link DataHandler}.
+     *
+     * @param desc The Descriptor you want to add.
+     */
+    public static void registerDescriptor(DataHandlerDescriptor desc) {
+        DataExchange api = DataExchange.getInstance();
+        api.getDescriptors().add(desc);
+    }
 
-	/**
-	 * Registers a File for automatic client syncing.
-	 *
-	 * @param modID The ID of the calling Mod
-	 * @param fileName The name of the File
-	 */
-	public static void addAutoSyncFile(String modID, File fileName){
-		getInstance().addAutoSyncFileData(modID, fileName, false, FileHash.NEED_TRANSFER);
-	}
+    /**
+     * Bulk-Add a Descriptors for your {@link DataHandler}-Objects.
+     *
+     * @param desc The Descriptors you want to add.
+     */
+    public static void registerDescriptors(List<DataHandlerDescriptor> desc) {
+        DataExchange api = DataExchange.getInstance();
+        api.getDescriptors().addAll(desc);
+    }
 
-	/**
-	 * Registers a File for automatic client syncing.
-	 *
-	 * @param modID The ID of the calling Mod
-	 * @param uniqueID A unique Identifier for the File. (see {@link ru.bclib.api.dataexchange.FileHash#uniqueID} for
-	 *                 Details
-	 * @param fileName The name of the File
-	 */
-	public static void addAutoSyncFile(String modID, String uniqueID, File fileName){
-		getInstance().addAutoSyncFileData(modID, uniqueID, fileName, false, FileHash.NEED_TRANSFER);
-	}
+    /**
+     * Sends the Handler.
+     * <p>
+     * Depending on what the result of {@link DataHandler#getOriginatesOnServer()}, the Data is sent from the server
+     * to the client (if {@code true}) or the other way around.
+     * <p>
+     * The method {@link DataHandler#serializeData(FriendlyByteBuf)} is called just before the data is sent. You should
+     * use this method to add the Data you need to the communication.
+     *
+     * @param h The Data that you want to send
+     */
+    public static void send(DataHandler h) {
+        if (h.getOriginatesOnServer()) {
+            DataExchangeAPI.getInstance().server.sendToClient(h);
+        } else {
+            DataExchangeAPI.getInstance().client.sendToServer(h);
+        }
+    }
 
-	/**
-	 * Registers a File for automatic client syncing.
-	 *
-	 * @param modID The ID of the calling Mod
-	 * @param fileName The name of the File
-	 * @param requestContent When {@code true} the content of the file is requested for comparison. This will copy the
-	 *                       entire file from the client to the server.
-	 *                       <p>
-	 *                       You should only use this option, if you need to compare parts of the file in order to decide
-	 *                       If the File needs to be copied. Normally using the {@link ru.bclib.api.dataexchange.FileHash}
-	 *                       for comparison is sufficient.
-	 * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
-	 */
-	public static void addAutoSyncFile(String modID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer){
-		getInstance().addAutoSyncFileData(modID, fileName, requestContent, needTransfer);
-	}
+    /**
+     * Registers a File for automatic client syncing.
+     *
+     * @param modID    The ID of the calling Mod
+     * @param fileName The name of the File
+     */
+    public static void addAutoSyncFile(String modID, File fileName) {
+        getInstance().addAutoSyncFileData(modID, fileName, false, FileHash.NEED_TRANSFER);
+    }
 
-	/**
-	 * Registers a File for automatic client syncing.
-	 *
-	 * @param modID The ID of the calling Mod
-	 * @param uniqueID A unique Identifier for the File. (see {@link ru.bclib.api.dataexchange.FileHash#uniqueID} for
-	 *                 Details
-	 * @param fileName The name of the File
-	 * @param requestContent When {@code true} the content of the file is requested for comparison. This will copy the
-	 *                       entire file from the client to the server.
-	 *                       <p>
-	 *                       You should only use this option, if you need to compare parts of the file in order to decide
-	 *                       If the File needs to be copied. Normally using the {@link ru.bclib.api.dataexchange.FileHash}
-	 *                       for comparison is sufficient.
-	 * @param needTransfer If the predicate returns true, the file needs to get copied to the server.
-	 */
-	public static void addAutoSyncFile(String modID, String uniqueID, File fileName, boolean requestContent, NeedTransferPredicate needTransfer){
-		getInstance().addAutoSyncFileData(modID, uniqueID, fileName, requestContent, needTransfer);
-	}
+    /**
+     * Registers a File for automatic client syncing.
+     * <p>
+     * The file is synced of the {@link FileHash} on client and server are not equal. This method will not copy the
+     * configs content from the client to the server.
+     *
+     * @param modID    The ID of the calling Mod
+     * @param uniqueID A unique Identifier for the File. (see {@link ru.bclib.api.dataexchange.FileHash#uniqueID} for
+     *                 Details
+     * @param fileName The name of the File
+     */
+    public static void addAutoSyncFile(String modID, String uniqueID, File fileName) {
+        getInstance().addAutoSyncFileData(modID, uniqueID, fileName, false, FileHash.NEED_TRANSFER);
+    }
+
+    /**
+     * Registers a File for automatic client syncing.
+     * <p>
+     * The content of the file is requested for comparison. This will copy the
+     * entire file from the client to the server.
+     * <p>
+     * You should only use this option, if you need to compare parts of the file in order to decide
+     * if the File needs to be copied. Normally using the {@link ru.bclib.api.dataexchange.FileHash}
+     * for comparison is sufficient.
+     *
+     * @param modID          The ID of the calling Mod
+     * @param fileName       The name of the File
+     * @param needTransfer   If the predicate returns true, the file needs to get copied to the server.
+     */
+    public static void addAutoSyncFile(String modID, File fileName, NeedTransferPredicate needTransfer) {
+        getInstance().addAutoSyncFileData(modID, fileName, true, needTransfer);
+    }
+
+    /**
+     * Registers a File for automatic client syncing.
+     * <p>
+     * The content of the file is requested for comparison. This will copy the
+     * entire file from the client to the server.
+     * <p>
+     * You should only use this option, if you need to compare parts of the file in order to decide
+     * if the File needs to be copied. Normally using the {@link ru.bclib.api.dataexchange.FileHash}
+     * for comparison is sufficient.
+     *
+     * @param modID          The ID of the calling Mod
+     * @param uniqueID       A unique Identifier for the File. (see {@link ru.bclib.api.dataexchange.FileHash#uniqueID} for
+     *                       Details
+     * @param fileName       The name of the File
+     * @param needTransfer   If the predicate returns true, the file needs to get copied to the server.
+     */
+    public static void addAutoSyncFile(String modID, String uniqueID, File fileName, NeedTransferPredicate needTransfer) {
+        getInstance().addAutoSyncFileData(modID, uniqueID, fileName, true, needTransfer);
+    }
 }

From 5bff609fb65316839cb9f1f12972843df5c61fb1 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 23:38:40 +0200
Subject: [PATCH 22/24] Invalidate request token

---
 src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
index df74449e..eed481d8 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
@@ -57,6 +57,7 @@ public class SendFiles extends DataHandler {
 			receivedFiles = new ArrayList<>(0);
 			return;
 		}
+		RequestFiles.newToken();
 
 		int size = buf.readInt();
 		receivedFiles = new ArrayList<>(size);

From 5c11fb5424e2942d8086dd3dd12a7ac61eb61580 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Fri, 6 Aug 2021 23:49:15 +0200
Subject: [PATCH 23/24] Invalidate tokens on fail

---
 src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
index eed481d8..05d71930 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
@@ -53,6 +53,7 @@ public class SendFiles extends DataHandler {
 	protected void deserializeFromIncomingData(FriendlyByteBuf buf, PacketSender responseSender, boolean fromClient) {
 		token = readString(buf);
 		if (!token.equals(RequestFiles.currentToken)) {
+			RequestFiles.newToken();
 			BCLib.LOGGER.error("Unrequested File Transfer!");
 			receivedFiles = new ArrayList<>(0);
 			return;

From ace3156fb25d44ed115a6f18198a4e527f8dada6 Mon Sep 17 00:00:00 2001
From: Frank <developer@ambertation.de>
Date: Sat, 7 Aug 2021 00:18:27 +0200
Subject: [PATCH 24/24] Additional Log output

---
 .../api/dataexchange/handler/AutoFileSyncEntry.java  |  5 +++--
 .../bclib/api/dataexchange/handler/HelloClient.java  | 10 +++++++---
 .../ru/bclib/api/dataexchange/handler/SendFiles.java | 12 ++++++++++--
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/AutoFileSyncEntry.java b/src/main/java/ru/bclib/api/dataexchange/handler/AutoFileSyncEntry.java
index 8ac37878..4211b3f8 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/AutoFileSyncEntry.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/AutoFileSyncEntry.java
@@ -4,6 +4,7 @@ import net.minecraft.network.FriendlyByteBuf;
 import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.FileHash;
 import ru.bclib.util.Pair;
+import ru.bclib.util.Triple;
 
 import java.io.File;
 import java.io.IOException;
@@ -53,13 +54,13 @@ class AutoFileSyncEntry extends DataExchange.AutoSyncID {
         return serializeFileContent(buf);
     }
 
-    public static Pair<AutoFileSyncEntry, byte[]> deserializeContent(FriendlyByteBuf buf) {
+    public static Triple<AutoFileSyncEntry, byte[], DataExchange.AutoSyncID> deserializeContent(FriendlyByteBuf buf) {
         final String modID = DataHandler.readString(buf);
         final String uniqueID = DataHandler.readString(buf);
         byte[] data = deserializeFileContent(buf);
 
         AutoFileSyncEntry entry = AutoFileSyncEntry.findMatching(modID, uniqueID);
-        return new Pair<>(entry, data);
+        return new Triple<>(entry, data, new DataExchange.AutoSyncID(modID, uniqueID));
     }
 
 
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
index d6a840dd..2fe5ff2b 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/HelloClient.java
@@ -54,16 +54,19 @@ public class HelloClient extends DataHandler {
 
 	@Override
 	protected void serializeData(FriendlyByteBuf buf) {
+		final String vbclib = getBCLibVersion();
+		BCLib.LOGGER.info("Sending Hello to Client. (server="+vbclib+")");
 		final List<String> mods = DataExchangeAPI.registeredMods();
 
 		//write BCLibVersion (=protocol version)
-		buf.writeInt(DataFixerAPI.getModVersion(getBCLibVersion()));
-
+		buf.writeInt(DataFixerAPI.getModVersion(vbclib));
 		//write Plugin Versions
 		buf.writeInt(mods.size());
 		for (String modID : mods) {
 			writeString(buf, modID);
-			buf.writeInt(DataFixerAPI.getModVersion(getModVersion(modID)));
+			final String ver = getModVersion(modID);
+			buf.writeInt(DataFixerAPI.getModVersion(ver));
+			BCLib.LOGGER.info("    - Listing Mod " + modID + " v" + ver);
 		}
 
 		//send config Data
@@ -72,6 +75,7 @@ public class HelloClient extends DataHandler {
 		for (AutoFileSyncEntry entry : autoSyncFiles) {
 			//System.out.println("Serializing " + entry.getFileHash());
 			entry.serialize(buf);
+			BCLib.LOGGER.info("    - Offering File " + entry);
 		}
 	}
 	
diff --git a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
index 05d71930..7742f523 100644
--- a/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
+++ b/src/main/java/ru/bclib/api/dataexchange/handler/SendFiles.java
@@ -13,7 +13,9 @@ import ru.bclib.api.dataexchange.DataHandler;
 import ru.bclib.api.dataexchange.DataHandlerDescriptor;
 import ru.bclib.gui.screens.ConfirmRestartScreen;
 import ru.bclib.util.Pair;
+import ru.bclib.util.Triple;
 
+import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -38,6 +40,12 @@ public class SendFiles extends DataHandler {
 	@Override
 	protected void serializeData(FriendlyByteBuf buf) {
 		List<AutoFileSyncEntry> existingFiles = files.stream().filter(e -> e.fileName.exists()).collect(Collectors.toList());
+		/*
+		//this will try to send a file that was not registered or requested by the client
+		existingFiles.add(new AutoFileSyncEntry("none", new File("D:\\MinecraftPlugins\\BetterNether\\run\\server.properties"),true,(a, b, content) -> {
+			System.out.println("Got Content:" + content.length);
+			return true;
+		}));*/
 		writeString(buf, token);
 		buf.writeInt(existingFiles.size());
 
@@ -64,12 +72,12 @@ public class SendFiles extends DataHandler {
 		receivedFiles = new ArrayList<>(size);
 		BCLib.LOGGER.info("Server sent " + size + " Files:");
 		for (int i=0; i<size; i++){
-			Pair<AutoFileSyncEntry, byte[]> p = AutoFileSyncEntry.deserializeContent(buf);
+			Triple<AutoFileSyncEntry, byte[], DataExchange.AutoSyncID> p = AutoFileSyncEntry.deserializeContent(buf);
 			if (p.first != null) {
 				receivedFiles.add(p);
 				BCLib.LOGGER.info("    - " + p.first + " (" + p.second.length + " Bytes)");
 			} else {
-				BCLib.LOGGER.error("    - Failed to receive File");
+				BCLib.LOGGER.error("   - Failed to receive File " +p.third+ ", possibly sent from a Mod that is not installed on the client.");
 			}
 		}
 	}