using System;
using System.Collections;
using System.Collections.Generic;
using BaseGames.Core;
using BaseGames.Core.Events;
using UnityEngine;

namespace BaseGames.EventChain
{
    /// <summary>
    /// 世界事件链管理器（架构 14_NarrativeModule §10）。
    /// 订阅游戏各系统的 SO 事件频道，转发为中继 C# 事件供 ChainCondition.Register() 绑定。
    /// 每当收到新事件时，检查所有链的触发条件。
    /// </summary>
    public class EventChainManager : MonoBehaviour
    {
        [Header("所有事件链")]
        [SerializeField] private EventChainSO[] _chains;

        [Header("事件频道（中继）")]
        [SerializeField] private StringEventChannelSO  _onBossDefeated;        // EVT_EnemyDied（bossId）
        [SerializeField] private StringEventChannelSO  _onCollectiblePickedUp; // EVT_CollectiblePickup
        [SerializeField] private StringEventChannelSO  _onAbilityUnlocked;     // EVT_AbilityUnlocked
        [SerializeField] private StringEventChannelSO  _onRoomEntered;         // EVT_SceneLoaded
        [SerializeField] private StringEventChannelSO  _onDialogueCompleted;   // EVT_NpcDialogueCompleted

        // ── 中继 C# 事件，供 ChainCondition.Register() 订阅 ──────────────
        public event Action<string> OnBossDefeated;
        public event Action<string> OnCollectiblePickedUp;
        public event Action<string> OnAbilityUnlocked;
        public event Action<string> OnRoomEntered;
        public event Action<string> OnDialogueCompleted;
        /// <summary>链执行完成时广播 chainId（供 ChainCompletedCondition）。</summary>
        public event Action<string> OnChainCompleted;

#if UNITY_EDITOR
        /// <summary>
        /// Editor 专用静态事件：链执行完成时向编辑器窗口推送日志。
        /// 仅在编辑器构建中存在，不产生运行时开销。
        /// EventChainEditorWindow 在 OnEnable 中订阅此事件。
        /// </summary>
        public static event Action<string, string> OnChainExecutedInEditor;
#endif

        private readonly HashSet<string> _completedChains = new();
        private readonly CompositeDisposable _subs = new();

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

        private void Awake()
        {
            // 从存档恢复已完成链
            var sm = ServiceLocator.GetOrDefault<ISaveService>();
            if (sm != null)
                foreach (var id in sm.GetCompletedChains())
                    _completedChains.Add(id);
        }

        private void OnEnable()
        {
            _onBossDefeated?.Subscribe(id        => { OnBossDefeated?.Invoke(id);        EvaluateAll(); }).AddTo(_subs);
            _onCollectiblePickedUp?.Subscribe(id => { OnCollectiblePickedUp?.Invoke(id); EvaluateAll(); }).AddTo(_subs);
            _onAbilityUnlocked?.Subscribe(id     => { OnAbilityUnlocked?.Invoke(id);    EvaluateAll(); }).AddTo(_subs);
            _onRoomEntered?.Subscribe(id         => { OnRoomEntered?.Invoke(id);        EvaluateAll(); }).AddTo(_subs);
            _onDialogueCompleted?.Subscribe(id   => { OnDialogueCompleted?.Invoke(id);  EvaluateAll(); }).AddTo(_subs);

            // 向每个 Condition 注册中继事件
            // 先重置 SO 资产上的运行时状态，防止跨 PlayMode 会话或多场景加载时状态残留
            if (_chains == null) return;
            foreach (var chain in _chains)
                if (chain?.conditions != null)
                    foreach (var cond in chain.conditions)
                    {
                        cond?.ResetState();
                        cond?.Register(this);
                    }
        }

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

            if (_chains == null) return;
            foreach (var chain in _chains)
                if (chain?.conditions != null)
                    foreach (var cond in chain.conditions)
                        cond?.Unregister(this);
        }

        // ── 评估逻辑 ──────────────────────────────────────────────────────
        /// <summary>收到新事件时立即评估所有链条件（无帧延迟）。</summary>
        private void EvaluateAll() => DoEvaluateAll();

        private void DoEvaluateAll()
        {
            if (_chains == null) return;
            foreach (var chain in _chains)
            {
                if (chain == null) continue;
                if (!chain.repeatable && _completedChains.Contains(chain.chainId)) continue;

                bool allMet = true;
                if (chain.conditions != null)
                    foreach (var cond in chain.conditions)
                        if (cond != null && !cond.IsMet()) { allMet = false; break; }

                if (allMet) StartCoroutine(ExecuteChain(chain));
            }
        }

        private IEnumerator ExecuteChain(EventChainSO chain)
        {
            // 防重入：一次性链立即标记为已完成
            if (!chain.repeatable) _completedChains.Add(chain.chainId);

            if (chain.actions != null)
                foreach (var action in chain.actions)
                {
                    if (action == null) continue;
                    yield return action.ExecuteAsync(this);
                    if (chain.actionDelay > 0f)
                        yield return new WaitForSeconds(chain.actionDelay);
                }

            ServiceLocator.GetOrDefault<ISaveService>()?.SetChainCompleted(chain.chainId);
            OnChainCompleted?.Invoke(chain.chainId);
#if UNITY_EDITOR
            OnChainExecutedInEditor?.Invoke(chain.chainId, "执行完成");
#endif
        }
    }
}