ConanServerManager/lib/statemachine.dart

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

import 'package:libac_dart/packets/packets.dart';
import 'package:libac_dart/utils/IOTools.dart';
import 'package:servermanager/game.dart';
import 'package:servermanager/proton.dart';
import 'package:servermanager/structs/SessionData.dart';
import 'package:servermanager/structs/mod.dart';
import 'package:servermanager/structs/settings.dart';

enum States {
  Idle, // For when the state machine is waiting for a state change
  PreStart, // Backup task
  Starting, // For when the server is starting up
  ModUpdateCheck, // For when the mods are being checked in the jail folder against the live mods
  WarnPlayersNonIntrusive, // Gives a non-instrusive warning about the upcoming restart
  WarnPlayersIntrusive, // Sends a message intrusively about the upcoming restart
  FullStop, // Intends to set the inactive state, and immediately stops the server

  Inactive // The inactive state will be used for when the state machine is not supposed to be doing anything.
}

enum WarnType { Intrusive, NonIntrusive }

enum WarnIntervals {
  FIVE_SECONDS(
      seconds: 5, type: WarnType.NonIntrusive, warning: "Tiiiiiimber!"),
  TEN_SECONDS(
      seconds: 10,
      type: WarnType.Intrusive,
      warning: "The server has 10 seconds until restart"),
  TWENTY_SECONDS(
      seconds: 20,
      type: WarnType.Intrusive,
      warning: "The server is about to go down in 20 seconds"),
  THIRTY_SECONDS(
      seconds: 30,
      type: WarnType.NonIntrusive,
      warning: "The server will restart in 30 seconds"),
  ONE_MINUTE(
      seconds: 60,
      type: WarnType.NonIntrusive,
      warning: "The server will restart in 1 minute"),
  FIVE_MIN(
      seconds: (5 * 60),
      type: WarnType.NonIntrusive,
      warning: "The server will restart in 5 minutes"),
  TEN_MIN(
      seconds: (10 * 60),
      type: WarnType.NonIntrusive,
      warning: "The server will restart in 10 minutes"),
  ONE_HOUR(
      seconds: (1 * 60 * 60),
      type: WarnType.NonIntrusive,
      warning: "The server will restart in 1 hour"),
  TWO_HOURS(
      seconds: (2 * 60 * 60),
      type: WarnType.NonIntrusive,
      warning: "The server will restart in 2 hours"),
  NONE(
      seconds: 2147483647,
      type: WarnType.NonIntrusive,
      warning:
          ""); // int32 max value should never be possible, is more seconds than in a single day.

  final int seconds;
  final WarnType type;
  final String warning;

  const WarnIntervals(
      {required this.seconds, required this.type, required this.warning});
}

class StateMachine {
  static Process? PROC;
  static Completer<void> DeadProcKillswitch = Completer();

  void resetKillswitch() {
    DeadProcKillswitch = Completer();
  }

  static Future<void> monitorProcess() async {
    try {
      int code = await PROC!.exitCode;
      DeadProcKillswitch.complete();
    } catch (E) {
      DeadProcKillswitch.complete();
    }
  }

  var _currentState = States.Inactive;
  StreamController<States> _stateController = StreamController.broadcast();
  Stream<States> get stateChanges => _stateController.stream;

  States get currentState => _currentState;

  void changeState(States n) {
    _currentState = n;
    _stateController.add(n);
  }

  Future<void> runTask() async {
    if (currentState == States.Idle) {
      return; // Nothing to do here
    } else if (currentState == States.FullStop) {
      Settings settings = Settings();
      print("Sending shutdown command to server");
      await settings.sendRconCommand("shutdown");

      Timer.periodic(Duration(seconds: 30), (timer) {
        timer.cancel();

        print("Sending killswitch to server");

        PROC!.kill(ProcessSignal.sigkill);
      });

      changeState(States.Inactive);
    } else if (currentState == States.Starting) {
      // Server startup in progress
      Settings settings = Settings();
      await settings.RunUpdate(valid: false);
      await doDownloadMods(false);

      settings.inst!.mods = await doScanMods(false);
      settings.Write();

      await settings.writeOutModListFile();

      var conanArgs = [
        "-RconEnabled=1",
        "-RconPassword=${settings.inst!.serverSettings.RconPassword}",
        "-RconPort=${settings.inst!.serverSettings.RconPort}",
        "-Port=${settings.inst!.serverSettings.GamePort}",
        "-QueryPort=${settings.inst!.serverSettings.QueryPort}",
        "-log",
        "-console"
      ];
      // Start the server now
      if (Platform.isWindows) {
        PROC = await Process.start(
            PathHelper.combine(
                settings.getServerPath(), "ConanSandboxServer.exe"),
            conanArgs,
            workingDirectory: settings.getServerPath());
      } else {
        runDetachedProton(
            PathHelper.combine(
                settings.getServerPath(), "ConanSandboxServer.exe"),
            conanArgs,
            settings.getServerPath());
      }

      changeState(States.Idle);
    } else if (currentState == States.PreStart) {
      // Perform Backup Task

      // Finally, allow the server to start up
      changeState(States.Starting);
    }
  }

  StateMachine() {
    stateChanges.listen((event) async {
      await runTask();
    });
  }

  Timer? task;

  /// You should only start this task once the server is ready to be started.
  /// This task will start the server on first-start
  ///
  /// It will monitor the states for shutdown, it will also monitor the process handle
  ///
  /// This is what runs the automatic restart timers as well. All state change logic that should happen automatically is contained in here.
  Future<void> startScheduler() async {
    Settings settings = Settings();
    SessionData.timer = settings.inst!.timer.time.copy();
    changeState(States.PreStart);

    resetKillswitch();
    SessionData.enableRestartTimer = settings.inst!.timer.enabled;

    // Schedule the server task
    task = Timer.periodic(Duration(seconds: 1), (timer) {
      switch (currentState) {
        case States.Inactive:
          {
            timer.cancel();

            //Settings settings = Settings();
            if (settings.inst!.pterodactylMode) {
              // Shut down the server processes now
              PacketServer.socket!.close();
            } else {
              resetKillswitch();
              SessionData.timer = settings.inst!.timer.time.copy();
              changeState(States.PreStart);
              SessionData.enableRestartTimer = settings.inst!.timer.enabled;
            }
            break;
          }
        case States.Idle:
          {
            // Restart timers and such
            SessionData.timer.tickDown();
            SessionData.operating_time.tickUp();
            SessionData.bumpModUpdateChecker();

            // Check if we should send an alert
            int sec = SessionData.timer.getTotalSeconds();
            WarnIntervals current = SessionData.CURRENT_INTERVAL;
            bool send = false;
            for (WarnIntervals WI in WarnIntervals.values) {
              if (WI.seconds <= sec && WI.seconds < current.seconds) {
                current = WI;
                send = true;

                break;
              }
            }

            if (send && SessionData.enableRestartTimer) {
              // Send the alert message
              SessionData.CURRENT_INTERVAL = current;
              if (current.type == WarnType.Intrusive) {
                settings.sendRconCommand("broadcast ${current.warning}");
              }
            }

            // Check Shutdown Pending
            if (SessionData.shutdownPending) {
              // Shut down the server
              changeState(States.FullStop);
              SessionData.shutdownPending = false;
            }

            // Check mod updates
            if (SessionData.shouldCheckModUpdates()) {
              Timer.periodic(Duration(seconds: 10), (timer) async {
                timer.cancel();
                SessionData.resetModUpdateChecker();

                await doDownloadMods(true);
                List<Mod> currentMods = await doScanMods(true);
                List<String> updatedMods = [];
                for (int i = 0; i < currentMods.length; i++) {
                  Mod currentMod = settings.inst!.mods[i];
                  Mod scannedMod = currentMods[i];

                  if (currentMod.mod_hash == scannedMod.mod_hash) {
                    // Mod is ok
                  } else {
                    // Mod is not ok
                    updatedMods.add("${scannedMod.mod_name}");
                  }
                }

                settings.sendRconCommand(
                    "broadcast The server will be going down for a restart in 5 minutes. The following mods have been updated: ${updatedMods.join(', ')}");
                SessionData.timer.apply((5 * 60));
                SessionData.enableRestartTimer = true;
              });
            }

            // Check Total Seconds
            if (SessionData.timer.getTotalSeconds() == 0 &&
                SessionData.enableRestartTimer) {
              SessionData.shutdownPending = true;
            }

            // Check Dead Process
            if (DeadProcKillswitch.isCompleted) {
              // Switch state
              changeState(States.FullStop); // This has the stop logic
            }

            break;
          }
        default:
          {
            break;
          }
      }
    });
  }
}