using System;
using System.Collections;
using System.Collections.Generic;
using AibisDream.FixSystem;
using AibisDream.Framework;
using AibisDream.Kit;
using AibisDream.SaveSystem;
using AibisDream.UI;
using UnityEngine;

namespace AibisDream
{
    public class GameManager : Singleton<GameManager>, IGameManager
    {
        #region 运行状态与章节数据

        public GameLoopState state;

        private List<TalkSceneSO> _totalSceneSos;

        [Header("生产环境数据（一般不动）")] public TalkSceneSO firstTalkSo;

        [Header("存档恢复补充章节")]
        [SerializeField] private List<TalkSceneSO> additionalRestoreSceneSos = new();

        #endregion

        private const float MainMenuFadeDuration = 0.5f;

        private BindProperty<TalkSceneSO> _currentTalkSceneSo;
        public override void OnSingletonInit()
        {
            LoadAllSceneSos();
        }

        private void Start()
        {
            // 管理游戏开始时各部分的初始化
            SettingLoader.Init();
            SnapshotRegistry.EnsureInitialized();
            // 场景So事件注册
            _currentTalkSceneSo = new BindProperty<TalkSceneSO>();

            StartCoroutine(AppBootstrapCoroutine());
        }

        /// <summary>
        /// 启动主界面：先黑屏，待本地化与 UI 就绪后再淡出，避免玩家看到初始化过程。
        /// </summary>
        private IEnumerator AppBootstrapCoroutine()
        {
            var playTool = UIManager.Instance.GetPanel<PlayToolPanel>();
            UIManager.Instance.ShowPanel<PlayToolPanel>();
            playTool?.ApplyFadeScreenCovered(true);

            yield return LocalizationKit.WaitUntilReady();

            EnumEventSystem.Global.Send(GameLoopEnum.AppStart);

            yield return LocalizationKit.WaitForUIRefresh();

            if (playTool != null)
            {
                yield return playTool.FadeOutAsync(MainMenuFadeDuration);
            }
        }

        private void LoadAllSceneSos()
        {
            _totalSceneSos = new List<TalkSceneSO>();
            var visited = new HashSet<TalkSceneSO>();
            var current = firstTalkSo;

            while (current != null && !visited.Contains(current))
            {
                _totalSceneSos.Add(current);
                visited.Add(current);
                current = current.GetNextScene();
            }
        }

        #region 游戏循环

        public void StartNewGame()
        {
            // 游戏开始
            EnumEventSystem.Global.Send(GameLoopEnum.GameStart);
            // 重置屏幕效果
            ScreenEffectManager.Instance?.ResetSaturation();
            // 序列
            _currentTalkSceneSo.Value = firstTalkSo;
            StartCoroutine(LoadFirstScene());
        }

        public void StartWithLevel(TalkSceneSO sceneSo)
        {
            // 游戏开始
            EnumEventSystem.Global.Send(GameLoopEnum.GameStart);
            // 重置屏幕效果
            ScreenEffectManager.Instance?.ResetSaturation();

            _currentTalkSceneSo.Value = sceneSo;
            StartCoroutine(LoadFirstScene());
        }

        public void StartWithSaveFile(string fileName)
        {
            // 游戏开始
            EnumEventSystem.Global.Send(GameLoopEnum.GameStart);

            StartCoroutine(LoadFromSaveFile(fileName));
        }

        public void StartWithSlot(int slotIndex)
        {
            // 游戏开始
            EnumEventSystem.Global.Send(GameLoopEnum.GameStart);

            StartCoroutine(LoadFromSlot(slotIndex));
        }

        private IEnumerator LoadFromSaveFile(string fileName)
        {
            yield return SaveRestoreOrchestrator.RestoreFromFile(fileName);
        }

        private IEnumerator LoadFromSlot(int slotIndex)
        {
            yield return SaveRestoreOrchestrator.RestoreFromSlot(slotIndex);
        }

        private IEnumerator LoadFirstScene()
        {
            ChapterController.Instance.UnlockChapter(_currentTalkSceneSo.Value);
            yield return UIManager.Instance.GetPanel<PlayToolPanel>().FadeInAsync(0.5f);
            yield return SceneLoader.Instance.LoadSceneAsync(_currentTalkSceneSo.Value.firstSceneName);
            yield return WaitForSceneDialogueReady();
            DialogController.Instance.StartDialog(_currentTalkSceneSo.Value.yarnProject);
        }

        /// <summary>
        /// 等待新场景 Awake/Start 完成，并等待场景协调器（Fix / Subway / Outside 等）就绪后再开对话。
        /// </summary>
        private static IEnumerator WaitForSceneDialogueReady()
        {
            yield return null;

            if (SceneHasDialogueGate())
            {
                while (HasPendingDialogueGate())
                {
                    yield return null;
                }
            }
            else
            {
                yield return null;
            }
        }

        private static bool SceneHasDialogueGate()
        {
            return FixSystemCenter.Instance != null
                   || SubwayCenter.Instance != null
                   || OutsideCenter.Instance != null;
        }

        private static bool HasPendingDialogueGate()
        {
            if (FixSystemCenter.Instance is ISceneDialogueGate { IsDialogueReady: false })
            {
                return true;
            }

            if (SubwayCenter.Instance is ISceneDialogueGate { IsDialogueReady: false })
            {
                return true;
            }

            if (OutsideCenter.Instance is ISceneDialogueGate { IsDialogueReady: false })
            {
                return true;
            }

            return false;
        }

        public void PauseGame()
        {
            // 系统暂停
            Time.timeScale = 0;
            // 交互继续
            EnumEventSystem.Global.Send(GameLoopEnum.PauseGame);
            // 音频全部暂停
            AudioManager.Instance.PauseAll();
            // 关闭Dialog
            DialogUIManager.Instance.CloseCanvas();
        }

        public void ContinueGame()
        {
            // 系统继续
            Time.timeScale = 1;
            // 交互继续
            EnumEventSystem.Global.Send(GameLoopEnum.UnPauseGame);
            // 音频继续
            AudioManager.Instance.UnPauseAll();
            // 打开Dialog
            DialogUIManager.Instance.OpenCanvas();
        }

        public void QuitGame()
        {
            // 系统继续
            Time.timeScale = 1;
            // 重置屏幕效果
            ScreenEffectManager.Instance?.ResetSaturation();
            // 卸载当前场景
            StartCoroutine(RestartCoroutine());
        }

        public void QuitApp()
        {
            Application.Quit();
        }

        private IEnumerator RestartCoroutine()
        {
            var playTool = UIManager.Instance.GetPanel<PlayToolPanel>();
            UIManager.Instance.ShowPanel<PlayToolPanel>();
            if (playTool != null)
            {
                yield return playTool.FadeInAsync(MainMenuFadeDuration);
            }

            // 清理所有系统注册
            if (FixSystemCenter.SystemDic != null)
            {
                FixSystemCenter.SystemDic.Clear();
            }

            playTool?.ClearPresentationEffects();

            // 执行场景卸载等功能
            CameraKit.Instance.ResetCamera();
            yield return SceneLoader.Instance.UnloadSceneAsync();
            DialogController.Instance.StopDialog();

            yield return LocalizationKit.WaitUntilReady();

            EnumEventSystem.Global.Send(GameLoopEnum.GameQuit);
            // 音频继续
            AudioManager.Instance.UnPauseAll();
            // 打开Dialog
            DialogUIManager.Instance.OpenCanvas();
            // 关闭结束面板
            UIManager.Instance.HidePanel<EndPanel>();

            yield return LocalizationKit.WaitForUIRefresh();

            if (playTool != null)
            {
                yield return playTool.FadeOutAsync(MainMenuFadeDuration);
            }
        }

        #endregion

        #region 分辨率与屏幕模式

        public void SetScreenMode(string windowMode)
        {
            int targetWidth, targetHeight;
            switch (windowMode)
            {
                case "FullScreen":
                    targetWidth = Screen.currentResolution.width;
                    targetHeight = Screen.currentResolution.height;
                    Screen.SetResolution(targetWidth, targetHeight, FullScreenMode.FullScreenWindow);
                    break;
                case "Windowed":
                    targetWidth = 1920;
                    targetHeight = 1080;
                    Screen.SetResolution(targetWidth, targetHeight, FullScreenMode.Windowed);
                    break;
                case "MaximizedWindow":
                    targetWidth = Screen.currentResolution.width;
                    targetHeight = Screen.currentResolution.height;
                    // Windows上没有MaximizedWindow模式，所以用FullScreenWindow代替
                    Screen.SetResolution(targetWidth, targetHeight, FullScreenMode.FullScreenWindow);
                    break;
                default:
                    return;
            }

            StartCoroutine(WaitForResolutionAndUpdateViewport(
                targetWidth, targetHeight));
        }

        private IEnumerator WaitForResolutionAndUpdateViewport(
            int targetWidth, int targetHeight)
        {
            float timeout = Time.unscaledTime + 1f;
            while ((Screen.width != targetWidth || Screen.height != targetHeight)
                   && Time.unscaledTime < timeout)
            {
                yield return null;
            }

            EnumEventSystem.Global.Send(GameLoopEnum.ScreenResolutionChanged);
        }

        #endregion

        public IEnumerator NextSceneSo(string exitName = null)
        {
            var next = _currentTalkSceneSo.Value?.GetNextScene(exitName);
            if (next != null)
            {
                _currentTalkSceneSo.Value = next;
                ChapterController.Instance.UnlockChapter(_currentTalkSceneSo.Value);
                yield return UIManager.Instance.GetPanel<PlayToolPanel>().FadeInAsync();
                yield return SceneLoader.Instance.LoadSceneAsync(_currentTalkSceneSo.Value.firstSceneName);
                yield return WaitForSceneDialogueReady();
                DialogController.Instance.StartDialog(_currentTalkSceneSo.Value.yarnProject);
            }
            else
            {
                Debug.Log($"没有下个场景了 (exitName: {exitName})");
                yield return null;
            }
        }

        public List<TalkSceneSO> GetAllSceneSos()
        {
            return _totalSceneSos;
        }

        public bool SetSceneSoByName(string soName)
        {
            var sceneSo = _totalSceneSos?.Find(so => so != null && so.name == soName);
            sceneSo ??= additionalRestoreSceneSos?.Find(so => so != null && so.name == soName);

            if (sceneSo == null)
            {
                Debug.LogError($"[GameManager] 找不到章节 SO：{soName}");
                return false;
            }

            _currentTalkSceneSo.Value = sceneSo;
            return true;
        }

        public void StartDialog()
        {
            DialogController.Instance.LoadDialog(_currentTalkSceneSo.Value.yarnProject);
        }

        public TalkSceneSO GetCurrentTalkSceneSo()
        {
            return _currentTalkSceneSo?.Value;
        }

        public string GetSceneSoName()
        {
            return _currentTalkSceneSo.Value.name;
        }

        #region 事件处理

        private IUnRegister[] _unRegisters;

        private void OnEnable()
        {
            RegisterEvents();
        }

        private void OnDisable()
        {
            UnRegisterEvents();
        }

        private void RegisterEvents()
        {
            _unRegisters = new IUnRegister[6];

            _unRegisters[0] = EnumEventSystem.Global.Register(GameLoopEnum.GameStart, () => state.OnGame(true));
            _unRegisters[1] = EnumEventSystem.Global.Register(GameLoopEnum.PauseGame, () => state.OnPause(true));

            _unRegisters[2] = EnumEventSystem.Global.Register(GameLoopEnum.GameQuit, () => state.OnGame(false));
            _unRegisters[3] = EnumEventSystem.Global.Register(GameLoopEnum.UnPauseGame, () => state.OnPause(false));

            _unRegisters[4] = EnumEventSystem.Global.Register(InteractionEventEnum.DialogStart, () => state.OnDialog(true));
            _unRegisters[5] = EnumEventSystem.Global.Register(InteractionEventEnum.DialogEnd, () => state.OnDialog(false));
        }

        private void UnRegisterEvents()
        {
            foreach (var unRegister in _unRegisters)
            {
                unRegister.UnRegister();
            }
        }

        #endregion
    }

    /// <summary>
    /// GameManager应该包含什么功能？
    /// 1. 游戏状态管理。开始/暂停/结束
    /// 2. 全局设置 即SettingLoader
    /// 3. 场景管理 有SceneLoader类，暂无必要
    /// 4. 资源管理 似无必要
    /// 5. 时间管理 主要供暂停使用
    /// 6. 日志和调试 日志已有
    /// </summary>
    public interface IGameManager
    {
        #region 游戏循环相关

        public void StartNewGame();
        public void PauseGame();
        public void ContinueGame();
        public void QuitGame();
        public void QuitApp();

        #endregion
    }

    public struct GameLoopState
    {
        public bool isInGame;
        public bool isInDialog;
        public bool isInPause;

        public void OnGame(bool isInGame)
        {
            this.isInGame = isInGame;
        }

        public void OnPause(bool isInPause)
        {
            this.isInPause = isInPause;
        }

        public void OnDialog(bool isInDialog)
        {
            this.isInDialog = isInDialog;
        }

        public bool IsInputAvailable()
        {
            return isInGame && isInDialog && !isInPause;
        }
    }

}