import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:libac_dart/nbt/NbtUtils.dart';
import 'package:libac_dart/nbt/Stream.dart';
import 'package:libac_dart/nbt/Tag.dart';
import 'package:libac_dart/nbt/impl/CompoundTag.dart';
import 'package:libac_dart/nbt/impl/ListTag.dart';
import 'package:libac_dart/nbt/impl/StringTag.dart';
import 'package:libac_dart/packets/packets.dart';
import 'package:libac_dart/utils/Hashing.dart';
import 'package:libac_dart/utils/IOTools.dart';
import 'package:libac_dart/utils/uuid/NbtUUID.dart';
import 'package:libac_dart/utils/uuid/UUID.dart';
import 'package:servermanager/statemachine.dart';
import 'package:servermanager/structs/SessionData.dart';
import 'package:servermanager/structs/credentials.dart';
import 'package:servermanager/structs/discordHookHelper.dart';
import 'package:servermanager/structs/settings.dart';

class ClientPackets {
  static void register() {
    PacketRegistry reg = PacketRegistry();
    reg.register(C2SLoginPacket(), () {
      return C2SLoginPacket();
    });
    reg.register(S2CLoginReply(), () {
      return S2CLoginReply();
    });
    reg.register(C2SRequestSettingsPacket(), () {
      return C2SRequestSettingsPacket();
    });
    reg.register(C2SUploadSettingsPacket(), () {
      return C2SUploadSettingsPacket();
    });
    reg.register(C2SRequestCreateBackup(), () {
      return C2SRequestCreateBackup();
    });
    reg.register(C2SRequestSnapshotList(), () {
      return C2SRequestSnapshotList();
    });
    reg.register(S2CSnapshotList(), () {
      return S2CSnapshotList();
    });
    reg.register(C2SRequestSnapshotDeletion(), () {
      return C2SRequestSnapshotDeletion();
    });
    reg.register(C2SRequestWorldRestore(), () {
      return C2SRequestWorldRestore();
    });
  }
}

class C2SLoginPacket implements IPacket {
  String username = "";
  String password = "";

  @override
  void decodeJson(String params) {
    fromJson(json.decode(params));
  }

  @override
  void decodeTag(Tag tag) {
    CompoundTag ct = tag.asCompoundTag();
    username = ct.get("username")!.asString();
    password = ct.get("password")!.asString();
  }

  @override
  NetworkDirection direction() {
    return NetworkDirection.ClientToServer;
  }

  @override
  String encodeJson() {
    return json.encode(toJson());
  }

  @override
  Tag encodeTag() {
    CompoundTag tag = CompoundTag();
    tag.put("username", StringTag.valueOf(username));
    tag.put("password", StringTag.valueOf(Hashing.sha256Hash(password)));

    return tag;
  }

  @override
  void fromJson(Map<String, dynamic> js) {
    username = js['username'] as String;
    password = js['password'] as String;
  }

  @override
  String getChannelID() {
    return "Login";
  }

  @override
  Future<PacketResponse> handleServerPacket() async {
    S2CResponse response = S2CResponse();
    S2CLoginReply loginReply = S2CLoginReply();

    // Attempt to log in.
    Settings settings = Settings();

    if (settings.superuser.login(username, password)) {
      settings.remoteLoginToken = UUID.generate(4);
      loginReply.valid = true;
      loginReply.token = settings.remoteLoginToken;

      settings.superuser.sendDiscordActionLog("Login Success");

      settings.loggedInUser = settings.superuser;
    } else {
      loginReply.valid = false;
    }

    // Properly handle the disabled account
    if (loginReply.valid && username == "_disabled") loginReply.valid = false;

    if (!loginReply.valid && settings.superuser.name != username) {
      // Check for a lower level user
      if (settings.inst!.admins.any((T) => T.name == username)) {
        User theUser =
            settings.inst!.admins.firstWhere((T) => T.name == username);
        if (theUser.login(username, password)) {
          settings.remoteLoginToken = UUID.generate(4);
          loginReply.valid = true;
          loginReply.token = settings.remoteLoginToken;

          theUser.sendDiscordActionLog("Login Success");

          settings.loggedInUser = theUser;
        } else {
          loginReply.valid = false;

          theUser.sendDiscordActionLog("Login Failed");
        }
      }
    }

    response.contents = loginReply.encodeTag().asCompoundTag();
    return PacketResponse(replyDataTag: response.encodeTag().asCompoundTag());
  }

  @override
  Map<String, dynamic> toJson() {
    return {"username": username, "password": Hashing.sha256Hash(password)};
  }

  @override
  Future<void> handleClientPacket() async {}
}

class S2CLoginReply implements IPacket {
  bool valid = false;
  UUID token = UUID.ZERO;

  @override
  void decodeJson(String params) {
    fromJson(json.decode(params));
  }

  @override
  void decodeTag(Tag tag) {
    print("Decoding S2C LoginReply");
    StringBuilder sb = StringBuilder();
    Tag.writeStringifiedNamedTag(tag, sb, 0);

    print(sb);
    CompoundTag ct = tag as CompoundTag;
    if (ct.containsKey("valid")) valid = NbtUtils.readBoolean(ct, "valid");
    if (ct.containsKey("token")) {
      token = NbtUtils.readUUID(ct, "token").toUUID();
    }
  }

  @override
  NetworkDirection direction() {
    return NetworkDirection.ServerToClient;
  }

  @override
  String encodeJson() {
    return json.encode(toJson());
  }

  @override
  Tag encodeTag() {
    CompoundTag tag = CompoundTag();
    NbtUtils.writeBoolean(tag, "valid", valid);
    NbtUtils.writeUUID(tag, "token", NbtUUID.fromUUID(token));
    return tag;
  }

  @override
  void fromJson(Map<String, dynamic> js) {
    valid = js['valid'] as bool;
    token = UUID.parse(js['token'] as String);
  }

  @override
  String getChannelID() {
    return "LoginReply";
  }

  @override
  Future<void> handleClientPacket() async {
    // Handle login finalization related stuff
    Settings settings = Settings();
    settings.remoteLoginToken = token;
  }

  @override
  Future<PacketResponse> handleServerPacket() async {
    return PacketResponse.nil; // We only operate on the client
  }

  @override
  Map<String, dynamic> toJson() {
    return {"valid": valid, "token": token.toString()};
  }
}

class C2SRequestSettingsPacket implements IPacket {
  CompoundTag serverSettings = CompoundTag();

  @override
  void decodeJson(String params) {
    throw UnsupportedError("Json is unsupported by LibACNBT at this time");
  }

  @override
  void decodeTag(Tag tag) {
    CompoundTag ct = tag as CompoundTag;
    serverSettings = ct.get("settings")!.asCompoundTag();
  }

  @override
  NetworkDirection direction() {
    return NetworkDirection.ClientToServer;
  }

  @override
  String encodeJson() {
    return "";
  }

  @override
  Tag encodeTag() {
    CompoundTag ct = CompoundTag();
    ct.put("settings", Settings().serialize());

    return ct;
  }

  @override
  void fromJson(Map<String, dynamic> js) {}

  @override
  String getChannelID() {
    return "C2SRequestSettings";
  }

  @override
  Future<void> handleClientPacket() async {
    Settings settings = Settings();
    settings.deserialize(serverSettings);
    settings.server = false;
  }

  @override
  Future<PacketResponse> handleServerPacket() async {
    S2CResponse response = S2CResponse();
    Settings settings = Settings();

    serverSettings = settings.serialize();
    response.contents = encodeTag().asCompoundTag();

    return PacketResponse(replyDataTag: response.encodeTag().asCompoundTag());
  }

  @override
  Map<String, dynamic> toJson() {
    return {};
  }
}

class C2SUploadSettingsPacket implements IPacket {
  CompoundTag srvSettings = CompoundTag();
  bool performRestart = false;

  @override
  void decodeJson(String params) {}

  @override
  void decodeTag(Tag tag) {
    CompoundTag ct = tag.asCompoundTag();

    srvSettings = ct.get("settings")!.asCompoundTag();
    performRestart = NbtUtils.readBoolean(ct, "restart");
  }

  @override
  NetworkDirection direction() {
    return NetworkDirection.ClientToServer;
  }

  @override
  String encodeJson() {
    return "";
  }

  @override
  Tag encodeTag() {
    CompoundTag tag = CompoundTag();
    tag.put("settings", Settings().serialize());
    NbtUtils.writeBoolean(tag, "restart", performRestart);

    return tag;
  }

  @override
  void fromJson(Map<String, dynamic> js) {}

  @override
  String getChannelID() {
    return "C2SUploadSettings";
  }

  @override
  Future<void> handleClientPacket() async {
    // No client response or handling needed
  }

  @override
  Future<PacketResponse> handleServerPacket() async {
    Settings settings = Settings();

    CompoundTag currentSettings = settings.serialize();
    try {
      settings.deserialize(srvSettings);
      settings.Write();

      DiscordHookHelper.sendWebHook(
          settings.inst!.discord,
          DiscordHookProps.ONLINE_ALERT,
          "Server Wrapper Settings",
          "Server wrapper settings have been updated.\n\n${performRestart ? "A restart has been requested" : "A restart is not needed"}");

      if (!performRestart) {
        return PacketResponse.nil;
      }

      // Send a webhook with all the mods listed
      String modListText = "";
      for (var entry in settings.inst!.mods) {
        if (entry.enabled) modListText += "${entry.mod_name}\n";
      }

      modListText = modListText.trim();
      if (modListText.isEmpty) {
        DiscordHookHelper.sendWebHook(
            settings.inst!.discord,
            DiscordHookProps.INACTIVE,
            "Mod List",
            "The Server is currently vanilla");
      } else {
        DiscordHookHelper.sendWebHook(settings.inst!.discord,
            DiscordHookProps.INACTIVE, "Mod List", modListText);
      }

      // Check if server is running, if not, stop immediately
      // If server is running, schedule restart for 1 minute and send a alert to all players, then perform stop or restart depending on if running in Pterodactyl Compatibility mode
      SessionData.shutdownMessage = "Server wrapper restart";
      SessionData.timer.apply(60);
      SessionData.CURRENT_INTERVAL = WarnIntervals.NONE;

      if (settings.subsys.currentState == States.Inactive) {
        Timer.periodic(Duration(seconds: 10), (timer) {
          SessionData.shutdownPending = true;
          // Stop packet server
          PacketServer.socket!.close();
          timer.cancel();
          exit(0);
        }); // We give time to allow the server to shut down gracefully.
      }

      return PacketResponse.nil;
    } catch (E) {
      settings.deserialize(currentSettings);
      return PacketResponse.nil;
    }
  }

  @override
  Map<String, dynamic> toJson() {
    return {};
  }
}

class C2SRequestCreateBackup implements IPacket {
  String fileName = ""; // File name of the backup

  @override
  void decodeJson(String params) {
    return; // Json not supported by this packet
  }

  @override
  void decodeTag(Tag tag) {
    if (tag is CompoundTag) {
      CompoundTag ct = tag.asCompoundTag();
      fileName = ct.get("name")!.asString();
    }
  }

  @override
  NetworkDirection direction() {
    return NetworkDirection.ClientToServer;
  }

  @override
  String encodeJson() {
    return "{}";
  }

  @override
  Tag encodeTag() {
    CompoundTag ct = CompoundTag();
    ct.put("name", StringTag.valueOf(fileName));

    return ct;
  }

  @override
  void fromJson(Map<String, dynamic> js) {}

  @override
  String getChannelID() {
    return "C2SRequestCreateBackup";
  }

  @override
  Future<void> handleClientPacket() async {
    // This is not handled on the client at all
  }

  @override
  Future<PacketResponse> handleServerPacket() async {
    // Copy the world file to the new destination
    Settings settings = Settings();

    File world = File(settings.getWorldGameDB());
    if (world.existsSync()) {
      // We're good!
      // Begin copy operations
      String destinationFile = "$fileName.db";
      PathHelper pth = PathHelper(pth: settings.getWorldSnapshotFolder())
          .resolve(destinationFile);
      world.copy(pth.build());

      settings.loggedInUser!
          .sendDiscordActionLog("Created a new backup named $fileName");
    }

    return PacketResponse.nil;
  }

  @override
  Map<String, dynamic> toJson() {
    return {};
  }
}

class C2SRequestSnapshotList implements IPacket {
  @override
  void decodeJson(String params) {}

  @override
  void decodeTag(Tag tag) {}

  @override
  NetworkDirection direction() {
    return NetworkDirection.ClientToServer;
  }

  @override
  String encodeJson() {
    return "{}";
  }

  @override
  Tag encodeTag() {
    return CompoundTag();
  }

  @override
  void fromJson(Map<String, dynamic> js) {}

  @override
  String getChannelID() {
    return "C2SRequestSnapshotList";
  }

  @override
  Future<void> handleClientPacket() async {}

  @override
  Future<PacketResponse> handleServerPacket() async {
    // Generate the list of all snapshot files
    Settings settings = Settings();

    List<String> snapshotFileNames = await settings.getWorldSnapshotFiles();
    S2CResponse response = S2CResponse();
    S2CSnapshotList snapshots = S2CSnapshotList();

    List<String> strippedFiles = [];
    for (String str in snapshotFileNames) {
      if (str.endsWith(".db")) {
        // add file name without db extension to the list

        String trimmedFileName = str.trim().substring(0, str.trim().length - 3);
        strippedFiles.add(
            trimmedFileName.substring(trimmedFileName.lastIndexOf("/") + 1));
      } else {
        strippedFiles.add(str);
      }
    }

    snapshots.snapshotFileNames = strippedFiles;

    response.contents = snapshots.encodeTag().asCompoundTag();
    return PacketResponse(replyDataTag: response.encodeTag().asCompoundTag());
  }

  @override
  Map<String, dynamic> toJson() {
    return {};
  }
}

class S2CSnapshotList implements IPacket {
  List<String> snapshotFileNames = [];

  @override
  void decodeJson(String params) {}

  @override
  void decodeTag(Tag tag) {
    CompoundTag ct = tag.asCompoundTag();

    ListTag lst = ct.get("items") as ListTag;
    for (int i = 0; i < lst.size(); i++) {
      snapshotFileNames.add(lst.get(i).asString());
    }
  }

  @override
  NetworkDirection direction() {
    return NetworkDirection.ServerToClient;
  }

  @override
  String encodeJson() {
    return "[]";
  }

  @override
  Tag encodeTag() {
    CompoundTag ct = CompoundTag();

    ListTag lst = ListTag();
    for (String str in snapshotFileNames) {
      lst.add(StringTag.valueOf(str));
    }

    ct.put("items", lst);
    return ct;
  }

  @override
  void fromJson(Map<String, dynamic> js) {}

  @override
  String getChannelID() {
    return "S2CSnapshotList";
  }

  @override
  Future<void> handleClientPacket() async {
    // Oh hey, its us!
    // Put the list in the SessionData
    SessionData.IE_SNAPSHOTS = snapshotFileNames;
  }

  @override
  Future<PacketResponse> handleServerPacket() {
    throw UnimplementedError();
  }

  @override
  Map<String, dynamic> toJson() {
    return {};
  }
}

class C2SRequestSnapshotDeletion implements IPacket {
  String snapshotName = "";

  @override
  void decodeJson(String params) {}

  @override
  void decodeTag(Tag tag) {
    CompoundTag ct = tag.asCompoundTag();
    snapshotName = ct.get("name")!.asString();
  }

  @override
  NetworkDirection direction() {
    return NetworkDirection.ClientToServer;
  }

  @override
  String encodeJson() {
    return "{}";
  }

  @override
  Tag encodeTag() {
    CompoundTag ct = CompoundTag();
    ct.put("name", StringTag.valueOf(snapshotName));

    return ct;
  }

  @override
  void fromJson(Map<String, dynamic> js) {}

  @override
  String getChannelID() {
    return "C2SRequestSnapshotDeletion";
  }

  @override
  Future<void> handleClientPacket() async {}

  @override
  Future<PacketResponse> handleServerPacket() async {
    Settings settings = Settings();

    String correctedName = "$snapshotName.db";
    PathHelper ph = PathHelper(pth: settings.getWorldSnapshotFolder())
        .resolve(correctedName);
    ph.deleteFile();

    settings.loggedInUser!.sendDiscordActionLog(
        "Requested snapshot deletion of backup named: $snapshotName");

    return PacketResponse.nil;
  }

  @override
  Map<String, dynamic> toJson() {
    return {};
  }
}

class C2SRequestWorldRestore implements IPacket {
  String snapshot = "";

  @override
  void decodeJson(String params) {}

  @override
  void decodeTag(Tag tag) {
    CompoundTag ct = tag.asCompoundTag();
    snapshot = ct.get("name")!.asString();
  }

  @override
  NetworkDirection direction() {
    return NetworkDirection.ClientToServer;
  }

  @override
  String encodeJson() {
    return "{}";
  }

  @override
  Tag encodeTag() {
    CompoundTag ct = CompoundTag();
    ct.put("name", StringTag.valueOf(snapshot));

    return ct;
  }

  @override
  void fromJson(Map<String, dynamic> js) {}

  @override
  String getChannelID() {
    return "C2SRequestWorldRestore";
  }

  @override
  Future<void> handleClientPacket() async {}

  @override
  Future<PacketResponse> handleServerPacket() async {
    Settings settings = Settings();

    SessionData.isWorldRestore = true;
    SessionData.snapshotToRestore = snapshot;
    SessionData.shutdownMessage = "A backup restore has been requested";
    SessionData.timer.apply(30);
    SessionData.CURRENT_INTERVAL = WarnIntervals.NONE;

    settings.loggedInUser!.sendDiscordActionLog(
        "Requested world restore, and initiated a immediate restart. World restored: $snapshot");

    return PacketResponse.nil;
  }

  @override
  Map<String, dynamic> toJson() {
    return {};
  }
}