using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.ResourceProviders;
using UnityEngine.SceneManagement;
using Debug = UnityEngine.Debug;
using Object = UnityEngine.Object;

// ReSharper disable Unity.LoadSceneWrongIndex

namespace BITKit.SceneManagement
{
	[Serializable]
	public class SceneServiceSingleton : SceneServiceImplement
	{
		protected override ISceneService _sceneServiceImplementation => SceneService.Singleton;
	}
	[Serializable]
	public class SceneServiceSingletonProxy:ISceneService
	{
		private ISceneService _sceneServiceImplementation => SceneService.Singleton;
		public bool InitializeMainSceneOnLoad=>SceneService.Singleton.InitializeMainSceneOnLoad;
		public UniTask LoadSceneAsync(string sceneName, CancellationToken cancellationToken,
			LoadSceneMode loadSceneMode = LoadSceneMode.Additive, bool activateOnLoad = true)=>SceneService.Singleton.LoadSceneAsync(sceneName,cancellationToken,loadSceneMode,activateOnLoad);

		public UniTask UnloadSceneAsync(string sceneName, CancellationToken cancellationToken)
		{
			return _sceneServiceImplementation.UnloadSceneAsync(sceneName, cancellationToken);
		}

		public event Action<string> OnLoadScene
		{
			add => SceneService.OnLoadScene += value;
			remove => SceneService.OnLoadScene -= value;
		}
		public event Action<string, float> OnSceneLoadProgress
		{
			add => SceneService.OnSceneLoadProgress += value;
			remove => SceneService.OnSceneLoadProgress -= value;
		}
		public event Action<string> OnSceneLoaded
		{
			add => SceneService.OnSceneLoaded += value;
			remove => SceneService.OnSceneLoaded -= value;
		}

		public event Action<string> OnUnloadScene
		{
			add => _sceneServiceImplementation.OnUnloadScene += value;
			remove => _sceneServiceImplementation.OnUnloadScene -= value;
		}

		public event Action<string> OnSceneUnloaded
		{
			add => _sceneServiceImplementation.OnSceneUnloaded += value;
			remove => _sceneServiceImplementation.OnSceneUnloaded -= value;
		}
	}

	public class SceneService : MonoBehaviour,ISceneService
	{
		#if UNITY_EDITOR
		public static bool AllowInitialize=true;
		[RuntimeInitializeOnLoadMethod]
		private static void Initialize()
		{
			OnLoadScene =null;
			OnSceneLoadProgress = null;
			OnSceneLoaded = null;
			if (AllowInitialize && SceneManager.sceneCount is not 0)
			{
				SceneManager.LoadSceneAsync(0);
			}
			
		}
#endif
		public static event Action<string> OnLoadScene;
		public static event Action<string, float> OnSceneLoadProgress;
		public static event Action<string> OnSceneLoaded;
		internal static SceneService Singleton;
#if UNITY_EDITOR
		[SerializeField] private Optional<float> allowLoadDelay;
#endif
		[SerializeField] private Optional<string> allowLoadMainScene;
		
		private CancellationToken _cancellationToken;
		private readonly List<SceneInstance> _loadedObjects = new();
		private void Awake()
		{
			Singleton = this;
			_cancellationToken = gameObject.GetCancellationTokenOnDestroy();
		}
		private void Start()
		{
			if (allowLoadMainScene.Allow is false) return;
			LoadSceneAsync(allowLoadMainScene.Value,_cancellationToken,LoadSceneMode.Single,false).Forget();
		}
		public bool InitializeMainSceneOnLoad => true;
		public async UniTask LoadSceneAsync(string sceneName,CancellationToken cancellationToken, LoadSceneMode loadSceneMode = LoadSceneMode.Additive,
			bool activateOnLoad = true)
		{
			try
			{
				var stopwatchWatcher = new Stopwatch();
				stopwatchWatcher.Start();
				BIT4Log.Log<SceneService>($"正在加载场景:{sceneName}");
				OnLoadScene?.Invoke(sceneName);
				
#if UNITY_EDITOR
				if (allowLoadDelay.Allow)
				{
					var progress = 0f;
					while (progress < allowLoadDelay.Value)
					{
						OnSceneLoadProgress?.Invoke(sceneName, progress +=1/allowLoadDelay.Value * Time.deltaTime);
						cancellationToken.ThrowIfCancellationRequested();
						await UniTask.NextFrame(cancellationToken);
					}
				}
#endif
				var asyncOperation = Addressables.LoadSceneAsync(sceneName, loadSceneMode, activateOnLoad);
				while (asyncOperation.IsDone is false)
				{
					await UniTask.NextFrame(cancellationToken);
					var progress = asyncOperation.PercentComplete;
					OnSceneLoadProgress?.Invoke(sceneName,progress);
				}
				OnSceneLoadProgress?.Invoke(sceneName, 1);
				await Task.Delay(100, cancellationToken);
				OnSceneLoaded?.Invoke(sceneName);
				stopwatchWatcher.Stop();
				if (activateOnLoad is false)
				{
					asyncOperation.Result.ActivateAsync().ToUniTask(cancellationToken: cancellationToken).Forget();
					_loadedObjects.Add(asyncOperation.Result);
				}
				BIT4Log.Log<SceneService>($"场景:{sceneName}加载完成,耗时:{stopwatchWatcher.ElapsedMilliseconds}ms");
			}
			catch (OperationCanceledException)
			{
				
			}
		}

		public async UniTask UnloadSceneAsync(string sceneName, CancellationToken cancellationToken)
		{
			await UniTask.SwitchToMainThread();
			OnUnloadScene?.Invoke(sceneName);
			foreach (var x in _loadedObjects)
			{
				await Addressables.UnloadSceneAsync(x);
			}
			OnSceneUnloaded?.Invoke(sceneName);
		}

		event  Action<string> ISceneService.OnLoadScene
		{
			add=>OnLoadScene+=value;
			remove=>OnLoadScene-=value;
		}

		event Action<string, float> ISceneService.OnSceneLoadProgress
		{
			add=>OnSceneLoadProgress+=value;
			remove => OnSceneLoadProgress -= value;
		}

		event Action<string> ISceneService.OnSceneLoaded
		{
			add=>OnSceneLoaded+=value;
			remove => OnSceneLoaded -= value;
		}

		public event Action<string> OnUnloadScene;
		public event Action<string> OnSceneUnloaded;
	}

}