import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

import '../facade_controller.dart';
import '../helpers/events.dart';
import 'device_method.dart';
import 'cocos_widget.dart';
import 'cocos_widget_platform.dart';

class MobileCocosWidgetController extends CocosWidgetController {
  final MobileCocosWidgetState _cocosWidgetState;

  /// The cocosId for this controller
  final int cocosId;

  /// used for cancel the subscription
  StreamSubscription? _onCocosMessageSub,
      _onCocosSceneLoadedSub,
      _onCocosUnloadedSub;

  MobileCocosWidgetController._(this._cocosWidgetState,
      {required this.cocosId}) {
    _connectStreams(cocosId);
  }

  /// Initialize [CocosWidgetController] with [id]
  /// Mainly for internal use when instantiating a [CocosWidgetController] passed
  /// in [CocosWidget.onCocosCreated] callback.
  static Future<MobileCocosWidgetController> init(
      int id, MobileCocosWidgetState cocosWidgetState) async {
    await CocosWidgetPlatform.instance.init(id);
    return MobileCocosWidgetController._(
      cocosWidgetState,
      cocosId: id,
    );
  }

  @visibleForTesting
  MethodChannel? get channel {
    if (CocosWidgetPlatform.instance is MethodChannelCocosWidget) {
      return (CocosWidgetPlatform.instance as MethodChannelCocosWidget)
          .channel(cocosId);
    }
    return null;
  }

  void _connectStreams(int cocosId) {
    if (_cocosWidgetState.widget.onCocosMessage != null) {
      _onCocosMessageSub = CocosWidgetPlatform.instance
          .onCocosMessage(cocosId: cocosId)
          .listen((CocosMessageEvent e) =>
              _cocosWidgetState.widget.onCocosMessage!(e.value));
    }

    if (_cocosWidgetState.widget.onCocosSceneLoaded != null) {
      _onCocosSceneLoadedSub = CocosWidgetPlatform.instance
          .onCocosSceneLoaded(cocosId: cocosId)
          .listen((CocosSceneLoadedEvent e) =>
              _cocosWidgetState.widget.onCocosSceneLoaded!(e.value));
    }

    if (_cocosWidgetState.widget.onCocosUnloaded != null) {
      _onCocosUnloadedSub = CocosWidgetPlatform.instance
          .onCocosUnloaded(cocosId: cocosId)
          .listen((_) => _cocosWidgetState.widget.onCocosUnloaded!());
    }
  }

  /// Checks to see if cocos player is ready to be used
  /// Returns `true` if cocos player is ready.
  Future<bool?>? isReady() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.isReady(cocosId: cocosId);
    }
    return null;
  }

  /// Get the current pause state of the cocos player
  /// Returns `true` if cocos player is paused.
  Future<bool?>? isPaused() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.isPaused(cocosId: cocosId);
    }
    return null;
  }

  /// Get the current load state of the cocos player
  /// Returns `true` if cocos player is loaded.
  Future<bool?>? isLoaded() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.isLoaded(cocosId: cocosId);
    }
    return null;
  }

  /// Helper method to know if Cocos has been put in background mode (WIP) unstable
  /// Returns `true` if cocos player is in background.
  Future<bool?>? inBackground() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.inBackground(cocosId: cocosId);
    }
    return null;
  }

  /// Creates a cocos player if it's not already created. Please only call this if cocos is not ready,
  /// or is in unloaded state. Use [isLoaded] to check.
  /// Returns `true` if cocos player was created succesfully.
  Future<bool?>? create() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.createCocosPlayer(cocosId: cocosId);
    }
    return null;
  }

  /// Post message to cocos from flutter. This method takes in a string [message].
  /// The [gameObject] must match the name of an actual cocos game object in a scene at runtime, and the [methodName],
  /// must exist in a `MonoDevelop` `class` and also exposed as a method. [message] is an parameter taken by the method
  ///
  /// ```dart
  /// postMessage("GameManager", "openScene", "ThirdScene")
  /// ```
  Future<void>? postMessage(String gameObject, methodName, message) {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.postMessage(
        cocosId: cocosId,
        gameObject: gameObject,
        methodName: methodName,
        message: message,
      );
    }
    return null;
  }

  /// Post message to cocos from flutter. This method takes in a Json or map structure as the [message].
  /// The [gameObject] must match the name of an actual cocos game object in a scene at runtime, and the [methodName],
  /// must exist in a `MonoDevelop` `class` and also exposed as a method. [message] is an parameter taken by the method
  ///
  /// ```dart
  /// postJsonMessage("GameManager", "openScene", {"buildIndex": 3, "name": "ThirdScene"})
  /// ```
  Future<void>? postJsonMessage(
      String gameObject, String methodName, Map<String, dynamic> message) {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.postJsonMessage(
        cocosId: cocosId,
        gameObject: gameObject,
        methodName: methodName,
        message: message,
      );
    }
    return null;
  }

  /// Pause the cocos in-game player with this method
  Future<void>? pause() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.pausePlayer(cocosId: cocosId);
    }
    return null;
  }

  /// Resume the cocos in-game player with this method idf it is in a paused state
  Future<void>? resume() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.resumePlayer(cocosId: cocosId);
    }
    return null;
  }

  /// Sometimes you want to open cocos in it's own process and openInNativeProcess does just that.
  /// It works for Android and iOS is WIP
  Future<void>? openInNativeProcess() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.openInNativeProcess(cocosId: cocosId);
    }
    return null;
  }

  /// Unloads cocos player from th current process (Works on Android only for now)
  /// iOS is WIP. For more information please read [Cocos Docs](https://docs.cocos3d.com/2020.2/Documentation/Manual/CocosasaLibrary.html)
  Future<void>? unload() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.unloadPlayer(cocosId: cocosId);
    }
    return null;
  }

  /// Quits cocos player. Note that this kills the current flutter process, thus quiting the app
  Future<void>? quit() {
    if (!_cocosWidgetState.widget.enablePlaceholder) {
      return CocosWidgetPlatform.instance.quitPlayer(cocosId: cocosId);
    }
    return null;
  }

  /// cancel the subscriptions when dispose called
  void _cancelSubscriptions() {
    _onCocosMessageSub?.cancel();
    _onCocosSceneLoadedSub?.cancel();
    _onCocosUnloadedSub?.cancel();

    _onCocosMessageSub = null;
    _onCocosSceneLoadedSub = null;
    _onCocosUnloadedSub = null;
  }

  void dispose() {
    _cancelSubscriptions();
    CocosWidgetPlatform.instance.dispose(cocosId: cocosId);
  }
}