using System.Collections.Generic;
using System.Linq;
using Cysharp.Threading.Tasks;
using PhxhSDK;
using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;
using UnityEngine.ResourceManagement.ResourceProviders;
using UnityEngine.SceneManagement;

namespace Gameplay.SubSystems
{
    public class GameSceneManager : Singlenton<GameSceneManager>
    {
        public class SceneHandle
        {
            public Scene Scene { get; private set; }

            public SceneHandle(Scene scene)
            {
                Scene = scene;
            }

            public Camera SceneMainCamera => Scene.GetRootGameObjects()
                .FirstOrDefault(r => r.GetComponent<Camera>() != null)?.GetComponent<Camera>();
        }

        public enum EnumScene
        {
            GameStart, // 登录场景
            GameMain, // 主场景
            GameLevel // 关卡（战场）场景
        }

        public const string SCENE_PREFIX = "Assets/Scenes/";
        public const string START_SCENE_NAME = "StartScene";
        public const string LEVEL_SCENE_NAME = "LevelScene";
        public const string MAIN_SCENE_NAME = "MainScene";
        public const string SCENE_SUFFIX = ".unity";

        private Dictionary<string, AsyncOperationHandle<SceneInstance>> _sceneOpDic = new();

        public async UniTask<LoadingResult> ChangeScene(EnumScene enumScene)
        {
            string sceneName = SCENE_PREFIX;
            switch (enumScene)
            {
                case EnumScene.GameStart:
                    sceneName += START_SCENE_NAME;
                    break;
                case EnumScene.GameMain:
                    sceneName += MAIN_SCENE_NAME;
                    break;
                case EnumScene.GameLevel:
                    sceneName += LEVEL_SCENE_NAME;
                    break;
                default:
                    DebugUtil.LogError("{0}.ChangeScene, {1} has no scene name matched", GetType(), enumScene);
                    sceneName += START_SCENE_NAME;
                    break;
            }

            sceneName += SCENE_SUFFIX;
            await LoadSceneAsync(sceneName);

            return LoadingResult.Success;
        }


        public async UniTask<SceneHandle> LoadSceneAsync(string scenePath, LoadSceneMode mode = LoadSceneMode.Single)
        {
            if (string.IsNullOrEmpty(scenePath))
            {
                DebugUtil.LogError($"ScenePath is null!");
                return null;
            }

            if (mode == LoadSceneMode.Single)
                _sceneOpDic.Clear();

            if (!_sceneOpDic.TryGetValue(scenePath, out var op))
            {
                op = Addressables.LoadSceneAsync(scenePath, mode);
                _sceneOpDic.Add(scenePath, op);
            }

            await op.ToUniTask();
            return new(op.Result.Scene);
        }

        public async UniTask UnLoadSceneAsync(string scenePath)
        {
            if (string.IsNullOrEmpty(scenePath))
            {
                DebugUtil.LogError($"ScenePath is null!");
                return;
            }

            if (!_sceneOpDic.TryGetValue(scenePath, out var op))
            {
                Debug.LogError($"该场景没有被加载过 scenePath:{scenePath}");
                return;
            }

            _sceneOpDic.Remove(scenePath);
            await Addressables.UnloadSceneAsync(op).ToUniTask();
        }

        public float GetSceneLoadingProgress(string scenePath)
        {
            if (_sceneOpDic.TryGetValue(scenePath, out var op))
            {
                return op.PercentComplete;
            }

            return 0;
        }
        
        /// <summary>
        /// 打开UI预览场景，当某个UI需要单独渲染场景时使用(如PVP布阵，营地等)
        /// 此时场景中的相机会只渲染UI场景内的物件
        /// </summary>
        /// <param name="scenePath"></param>
        /// <param name="mode"></param>
        /// <returns></returns>
        public async UniTask<SceneHandle> LoadSceneForUIView(string scenePath,
            LoadSceneMode mode = LoadSceneMode.Single)
        {
            var sceneHandle = await LoadSceneAsync(scenePath, mode);
            if (sceneHandle == null)
            {
                return null;
            }

            var scene = sceneHandle.Scene;
            var groundLayer = LayerMask.NameToLayer("Ground");
            var UIViewLayer = LayerMask.NameToLayer("UIView");
            var UIViewMask = LayerMask.GetMask("UIView","Ground");
            //调整所有物品的层级
            var roots = scene.GetRootGameObjects();
            foreach (var root in roots)
            {
                //将所有gameObject设置为UIView层
                root.SetLayerEx(UIViewLayer,groundLayer);
            }

            //设置相机的culling mask
            foreach (var root in roots)
            {
                var cam = root.GetComponent<Camera>();
                if (!cam)
                    continue;
                cam.cullingMask = UIViewMask;
            }

            //设置光源culling mask
            var lights = Object.FindObjectsOfType<Light>();
            foreach (var light in lights)
            {
                if (light.gameObject.scene != scene)
                    continue;
                light.cullingMask = UIViewMask;
            }

            //切换全局GI
            SceneManager.SetActiveScene(scene);
            var result = new SceneHandle(scene);
            //CameraManager.Instance.AddCameraStack(sceneHandle.SceneMainCamera);
            sceneHandle.SceneMainCamera.targetTexture = CameraManager.Instance.MainCamera.targetTexture;
            return result;
        }
    }
}