using BaseGames.Core.Events;
using BaseGames.Input;
using UnityEngine;
using UnityEngine.Playables;
using UnityEngine.Timeline;

namespace BaseGames.Cutscene
{
    /// <summary>
    /// Unity Timeline 过场动画封装（架构 14_NarrativeModule §11）。
    /// 负责播放/停止 CutsceneSO；切换 Action Map；广播过场开始/结束事件。
    /// </summary>
    [RequireComponent(typeof(PlayableDirector))]
    public class CutsceneManager : MonoBehaviour
    {
        [SerializeField] private InputReaderSO _inputReader;

        [Header("事件频道")]
        [SerializeField] private VoidEventChannelSO   _onCutsceneStarted;
        [SerializeField] private VoidEventChannelSO   _onCutsceneEnded;
        [SerializeField] private StringEventChannelSO _onPlayCutsceneById;  // 由 PlayCutsceneAction 触发

        [Header("过场素材库（PlayById 查找用）")]
        [SerializeField] private CutsceneSO[] _registeredCutscenes;

        private PlayableDirector _director;
        private readonly CompositeDisposable _subs = new();
        private System.Action _onCompletedCallback;

        /// <summary>是否正在播放过场。</summary>
        public bool IsPlaying => _director != null && _director.state == PlayState.Playing;

        // ── 生命周期 ──────────────────────────────────────────────────────

        private void Awake()
        {
            _director = GetComponent<PlayableDirector>();
        }

        private void OnEnable()
        {
            _onPlayCutsceneById?.Subscribe(PlayById).AddTo(_subs);
        }

        private void OnDisable()
        {
            _subs.Clear();
        }

        // ── 公开 API ──────────────────────────────────────────────────────

        /// <summary>通过 cutsceneId 查找并播放（供 PlayCutsceneAction 通过事件触发）。</summary>
        public void PlayById(string cutsceneId)
        {
            if (_registeredCutscenes == null) return;
            foreach (var cs in _registeredCutscenes)
                if (cs != null && cs.cutsceneId == cutsceneId) { PlayCutscene(cs); return; }

            Debug.LogWarning($"[CutsceneManager] 找不到 cutsceneId='{cutsceneId}'");
        }

        /// <summary>
        /// 播放指定过场 SO。
        /// <paramref name="onCompleted"/>：过场完全结束（PlayableDirector.stopped）后调用，
        /// 可用于写入存档 flag 等需要在播完后执行的逻辑。
        /// </summary>
        public void PlayCutscene(CutsceneSO cutscene, System.Action onCompleted = null)
        {
            if (cutscene == null || IsPlaying) return;
            _onCompletedCallback = onCompleted;
            _director.playableAsset = cutscene.Timeline;

            // 应用 Track → GameObject 绑定
            if (cutscene.Bindings != null && cutscene.Timeline != null)
            {
                var outputs = cutscene.Timeline.outputs;
                int idx = 0;
                foreach (var output in outputs)
                {
                    if (idx >= cutscene.Bindings.Length) break;
                    var binding = cutscene.Bindings[idx];
                    if (!string.IsNullOrEmpty(binding.trackName) && output.streamName == binding.trackName
                        && binding.target != null)
                    {
                        _director.SetGenericBinding(output.sourceObject, binding.target);
                    }
                    idx++;
                }
            }

            _director.stopped += OnCutsceneStopped;
            _director.Play();

            _inputReader?.EnableUIInput();
            _onCutsceneStarted?.Raise();
        }

        /// <summary>立即停止当前过场。</summary>
        public void StopCutscene()
        {
            if (_director != null) _director.Stop();
        }

        // ── 内部 ──────────────────────────────────────────────────────────

        private void OnCutsceneStopped(PlayableDirector director)
        {
            _director.stopped -= OnCutsceneStopped;
            _inputReader?.EnableGameplayInput();
            _onCutsceneEnded?.Raise();
            // 取出并调用完成回调（清空后调用，防止回调内再次触发 PlayCutscene 时覆盖）
            var cb = _onCompletedCallback;
            _onCompletedCallback = null;
            cb?.Invoke();
        }
    }
}