using UnityEngine;
using BaseGames.Core;
using BaseGames.Core.Events;
using BaseGames.Core.Save;

namespace BaseGames.Progression
{
    /// <summary>
    /// 进程锁（架构 09_ProgressionModule §12）。
    /// 单向/永久性阻挡，需满足特定条件（击败 Boss）才能解锁。
    /// 通过 ServiceLocator.GetOrDefault&lt;SaveManager&gt;() 读取进度，订阅 BossDefeated 事件实时响应。
    /// </summary>
    public class ProgressLock : MonoBehaviour, ISaveable
    {
        [Header("解锁条件")]
        [SerializeField] private string _requiredBossId;   // 空 = 不检查 Boss
        [SerializeField] private string _requiredItemId;   // 空 = 不检查道具（P1 预留）

        [Header("物理表现")]
        [SerializeField] private GameObject _lockedVisuals;    // 锁住状态视觉
        [SerializeField] private GameObject _unlockedVisuals;  // 开启状态视觉（可 null）
        [SerializeField] private Collider2D _blockCollider;

        [Header("存档")]
        [SerializeField] private string _lockId;   // 唯一 ID，存档记录开启状态

        [Header("Event Channels")]
        [SerializeField] private StringEventChannelSO _onBossDefeated;  // EVT_BossDefeated

        private readonly CompositeDisposable _subs = new();
        private bool _isUnlocked;

        private void Awake()
        {
            ServiceLocator.GetOrDefault<ISaveableRegistry>()?.Register(this);
        }

        private void OnDestroy()
        {
            ServiceLocator.GetOrDefault<ISaveableRegistry>()?.Unregister(this);
        }

        private void Start()
        {
            ApplyState(CheckUnlocked());
        }

        private void OnEnable()
        {
            _onBossDefeated?.Subscribe(OnBossDefeated).AddTo(_subs);
        }

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

        private void OnBossDefeated(string bossId)
        {
            if (!string.IsNullOrEmpty(_requiredBossId) && bossId != _requiredBossId) return;
            if (CheckUnlocked()) ApplyState(true);
        }

        // ── ISaveable ─────────────────────────────────────────────────────────
        public void OnSave(SaveData data)
        {
            if (_isUnlocked && !string.IsNullOrEmpty(_lockId)
                && !data.World.OpenedDoors.Contains(_lockId))
                data.World.OpenedDoors.Add(_lockId);
        }

        public void OnLoad(SaveData data)
        {
            // 状态由 CheckUnlocked() 读取 IsDoorOpened(从 SaveData.OpenedDoors)，应于 Start() 和 OnBossDefeated() 重新评估
        }

        private bool CheckUnlocked()
        {
            var sm = ServiceLocator.GetOrDefault<ISaveService>();
            if (sm == null) return false;

            if (!string.IsNullOrEmpty(_requiredBossId) && !sm.IsBossDefeated(_requiredBossId))
                return false;

            return string.IsNullOrEmpty(_lockId) || sm.IsDoorOpened(_lockId);
        }

        private void ApplyState(bool unlocked)
        {
            _isUnlocked = unlocked;
            if (_blockCollider    != null) _blockCollider.enabled = !unlocked;
            if (_lockedVisuals    != null) _lockedVisuals.SetActive(!unlocked);
            if (_unlockedVisuals  != null) _unlockedVisuals.SetActive(unlocked);
        }
    }
}