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

namespace BaseGames.EventChain
{
    // =====================================================================
    //  EventChainSO  ——  世界事件链数据（架构 14_NarrativeModule §9）
    // =====================================================================

    /// <summary>
    /// 世界事件链：描述"当全部 conditions 满足时，依序执行 actions"。
    /// 策划纯数据配置，无需程序员介入。
    /// 资产路径：Assets/ScriptableObjects/EventChains/Chain_{Context}.asset
    /// </summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/EventChain")]
    public class EventChainSO : ScriptableObject
    {
        [Header("基础")]
        public string  chainId;               // 全局唯一，如 "Chain_BossForest_Defeated"
        public bool    repeatable;            // false = 只触发一次（触发后存档记录）
        [Min(0f)]
        public float   actionDelay = 0f;      // 各 action 之间的延迟（秒），0 = 紧接着执行

        [Header("触发条件（全部满足才触发）")]
        public ChainCondition[] conditions;

        [Header("执行动作（顺序执行）")]
        public ChainAction[]    actions;
    }

    // =====================================================================
    //  ChainCondition 抽象基类 + 内置实现
    // =====================================================================

    /// <summary>
    /// 事件链触发条件抽象基类（Strategy + Observer 混合）。
    /// Register/Unregister 向 EventChainManager 的中继 C# 事件挂钩，
    /// IsMet() 被 EvaluateAll() 调用以检验是否满足触发条件。
    /// </summary>
    public abstract class ChainCondition : ScriptableObject
    {
        public abstract void Register(EventChainManager manager);
        public abstract void Unregister(EventChainManager manager);
        public abstract bool IsMet();
        /// <summary>
        /// 重置运行时瞬态状态（每次 EventChainManager.OnEnable 时调用）。
        /// ScriptableObject 是资产，_met 等字段会跨 PlayMode 会话残留；
        /// 显式重置确保每次进入游戏/切换场景时条件均从初始状态开始评估。
        /// </summary>
        public virtual void ResetState() { }
    }

    // ─── 内置条件 ──────────────────────────────────────────────────────────

    [CreateAssetMenu(menuName = "BaseGames/EventChain/Condition/BossDefeated")]
    public class BossDefeatedCondition : ChainCondition
    {
        public string bossId;
        private bool _met;
        public override void Register(EventChainManager m)   => m.OnBossDefeated   += Check;
        public override void Unregister(EventChainManager m) => m.OnBossDefeated   -= Check;
        public override bool IsMet() => _met;
        public override void ResetState() => _met = false;
        private void Check(string id) { if (id == bossId) _met = true; }
    }

    [CreateAssetMenu(menuName = "BaseGames/EventChain/Condition/FlagSet")]
    public class FlagSetCondition : ChainCondition
    {
        public string flagId;
        public override void Register(EventChainManager m)   { }  // 持续轮询，无需订阅
        public override void Unregister(EventChainManager m) { }
        public override bool IsMet() { var sm = ServiceLocator.GetOrDefault<ISaveService>(); return sm != null && sm.GetFlag(flagId); }
    }

    [CreateAssetMenu(menuName = "BaseGames/EventChain/Condition/AbilityUnlocked")]
    public class AbilityUnlockedCondition : ChainCondition
    {
        public string abilityId;
        private bool _met;
        public override void Register(EventChainManager m)   => m.OnAbilityUnlocked   += Check;
        public override void Unregister(EventChainManager m) => m.OnAbilityUnlocked   -= Check;
        public override bool IsMet() => _met;
        public override void ResetState() => _met = false;
        private void Check(string id) { if (id == abilityId) _met = true; }
    }

    [CreateAssetMenu(menuName = "BaseGames/EventChain/Condition/CollectibleCollected")]
    public class CollectibleCollectedCondition : ChainCondition
    {
        public string itemId;
        private bool _met;
        public override void Register(EventChainManager m)   => m.OnCollectiblePickedUp += Check;
        public override void Unregister(EventChainManager m) => m.OnCollectiblePickedUp -= Check;
        public override bool IsMet() => _met;
        public override void ResetState() => _met = false;
        private void Check(string id) { if (id == itemId) _met = true; }
    }

    [CreateAssetMenu(menuName = "BaseGames/EventChain/Condition/RoomEntered")]
    public class RoomEnteredCondition : ChainCondition
    {
        public string sceneName;
        private bool _met;
        public override void Register(EventChainManager m)   => m.OnRoomEntered   += Check;
        public override void Unregister(EventChainManager m) => m.OnRoomEntered   -= Check;
        public override bool IsMet() => _met;
        public override void ResetState() => _met = false;
        private void Check(string id) { if (id == sceneName) _met = true; }
    }

    [CreateAssetMenu(menuName = "BaseGames/EventChain/Condition/DialogueCompleted")]
    public class DialogueCompletedCondition : ChainCondition
    {
        public string npcId;
        private bool _met;
        public override void Register(EventChainManager m)   => m.OnDialogueCompleted += Check;
        public override void Unregister(EventChainManager m) => m.OnDialogueCompleted -= Check;
        public override bool IsMet() => _met;
        public override void ResetState() => _met = false;
        private void Check(string id) { if (id == npcId) _met = true; }
    }

    [CreateAssetMenu(menuName = "BaseGames/EventChain/Condition/ChainCompleted")]
    public class ChainCompletedCondition : ChainCondition
    {
        public string chainId;
        private bool _met;
        public override void Register(EventChainManager m)   => m.OnChainCompleted += Check;
        public override void Unregister(EventChainManager m) => m.OnChainCompleted -= Check;
        public override bool IsMet() => _met;
        public override void ResetState() => _met = false;
        private void Check(string id) { if (id == chainId) _met = true; }
    }

    // =====================================================================
    //  ChainAction 抽象基类 + 内置实现
    // =====================================================================

    /// <summary>
    /// 事件链执行动作抽象基类。ExecuteAsync 可即时返回或协程等待。
    /// </summary>
    public abstract class ChainAction : ScriptableObject
    {
        public abstract IEnumerator ExecuteAsync(MonoBehaviour runner);
    }

    // ─── 内置动作 ──────────────────────────────────────────────────────────

    /// <summary>打开门（发布 EVT_DoorOpened 事件）。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/OpenDoor")]
    public class OpenDoorAction : ChainAction
    {
        public string doorId;
        [SerializeField] private StringEventChannelSO _onDoorOpened;  // EVT_DoorOpened
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            _onDoorOpened?.Raise(doorId);
            yield break;
        }
    }

    /// <summary>设置/清除存档标志。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/SetFlag")]
    public class SetFlagAction : ChainAction
    {
        public string flagId;
        public bool   value = true;
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            ServiceLocator.GetOrDefault<ISaveService>()?.SetFlag(flagId, value);
            yield break;
        }
    }

    /// <summary>通知地图显示/标记区域（通过事件频道解耦，无直接 MapManager 依赖）。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/UpdateMap")]
    public class UpdateMapAction : ChainAction
    {
        public string regionId;
        [SerializeField] private StringEventChannelSO _onRevealRegion;  // EVT_RevealRegion → MapManager 订阅
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            _onRevealRegion?.Raise(regionId);
            yield break;
        }
    }

    /// <summary>播放过场动画，等待其结束再继续链。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/PlayCutscene")]
    public class PlayCutsceneAction : ChainAction
    {
        public string cutsceneId;
        [SerializeField] private StringEventChannelSO _onPlayCutscene;  // → CutsceneManager.PlayById
        [SerializeField] private VoidEventChannelSO   _onCutsceneEnded; // ← CutsceneManager 播完后 Raise
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            bool done = false;
            var sub = _onCutsceneEnded != null
                ? _onCutsceneEnded.Subscribe(() => done = true)
                : default(EventSubscription);
            _onPlayCutscene?.Raise(cutsceneId);
            yield return new WaitUntil(() => done);
            sub.Dispose();
        }
    }

    /// <summary>切换 NPC 对话（通过 EVT_NPCDialogueChange 广播，NPC 自行响应）。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/ChangeNPCDialogue")]
    public class ChangeNPCDialogueAction : ChainAction
    {
        public string npcId;
        public string newSequenceId;
        [SerializeField] private StringEventChannelSO _onNPCDialogueChange;  // EVT_NPCDialogueChange → NPC 订阅
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            _onNPCDialogueChange?.Raise($"{npcId}:{newSequenceId}");
            yield break;
        }
    }

    /// <summary>在场景中生成一个预制体。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/SpawnObject")]
    public class SpawnObjectAction : ChainAction
    {
        public GameObject prefab;
        public Vector3    position;
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            if (prefab != null)
                UnityEngine.Object.Instantiate(prefab, position, Quaternion.identity);
            yield break;
        }
    }

    /// <summary>等待指定秒数。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/Wait")]
    public class WaitAction : ChainAction
    {
        [Min(0f)]
        public float seconds;
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            yield return new WaitForSeconds(seconds);
        }
    }

    /// <summary>发布一个无负载 Void 事件频道。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/RaiseEvent")]
    public class RaiseEventAction : ChainAction
    {
        [SerializeField] private VoidEventChannelSO _eventChannel;
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            _eventChannel?.Raise();
            yield break;
        }
    }

    /// <summary>解锁能力（通过 EVT_AbilityUnlocked 事件广播，PlayerStats 响应）。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/UnlockAbility")]
    public class UnlockAbilityAction : ChainAction
    {
        public string abilityId;
        [SerializeField] private StringEventChannelSO _onAbilityUnlock;  // EVT_AbilityUnlocked
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            _onAbilityUnlock?.Raise(abilityId);
            yield break;
        }
    }

    /// <summary>切换背景音乐（通过 EVT_PlayBGM 事件广播）。</summary>
    [CreateAssetMenu(menuName = "BaseGames/EventChain/Action/PlayAudio")]
    public class PlayAudioAction : ChainAction
    {
        public string bgmKey;
        [SerializeField] private StringEventChannelSO _onPlayBGM;  // EVT_PlayBGM
        public override IEnumerator ExecuteAsync(MonoBehaviour runner)
        {
            _onPlayBGM?.Raise(bgmKey);
            yield break;
        }
    }
}