using System;
using System.Threading.Tasks;
using UnityEngine;
using BaseGames.Core;
using BaseGames.Core.Events;
using BaseGames.Core.Save;

namespace BaseGames.World
{
    /// <summary>
    /// 存档点（也是复活点）。
    /// 玩家互动后：恢复 HP → 写入存档（场景、出生点 ID、世界状态）→ 广播激活事件。
    /// 传送点（快速旅行面板）是独立的 TeleportStation 组件，不在此处处理。
    ///
    /// 继承 SaveableMonoBehaviour 以自动向 ISaveableRegistry 注册/注销，
    /// 确保 GameSaveManager 在 SaveAsync/LoadAsync 时回调本组件。
    ///
    /// OnSave 仅在 _isActivated=true 时写入复活字段，
    /// 防止自动存档期间未激活的存档点覆盖玩家的正确复活位置。
    /// </summary>
    public class SavePoint : SaveableMonoBehaviour, IInteractable
    {
        [Header("Config")]
        [SerializeField] private string _savePointId;
        [SerializeField] private bool   _restoreSpring = true;

        [Header("Event Channels - Listen")]
        [Tooltip("EVT_SceneLoaded — 用于追踪当前场景名，写入 Player.Scene")]
        [SerializeField] private StringEventChannelSO _onSceneLoaded;

        [Header("Event Channels - Raise")]
        [SerializeField] private StringEventChannelSO _onSavePointActivated;

        private bool   _isActivated;
        private string _currentSceneName;

        private readonly CompositeDisposable _subs = new();

        protected override void OnEnable()
        {
            base.OnEnable(); // 向 ISaveableRegistry 注册，确保 OnSave/OnLoad 被回调
            _onSceneLoaded?.Subscribe(OnSceneLoaded).AddTo(_subs);
        }

        protected override void OnDisable()
        {
            base.OnDisable(); // 从 ISaveableRegistry 注销
            _subs.Clear();
        }

        private void OnSceneLoaded(string sceneName) => _currentSceneName = sceneName;

        // ── IInteractable ──────────────────────────────────────────────────────
        public bool   CanInteract    => true;
        public string InteractPrompt => _isActivated ? "休息" : "激活";

        public void Interact(Transform player)
        {
            _isActivated = true;

            var restorer = player.GetComponentInChildren<IRestoreOnSave>();
            if (restorer != null)
            {
                restorer.FullRestore();
                if (_restoreSpring) restorer.RestoreSpring();
            }

            _onSavePointActivated?.Raise(_savePointId);

            // 触发存档：OnSave() 由 SaveAsync 回调所有 ISaveable，包含本组件
            var svc = ServiceLocator.GetOrDefault<ISaveService>();
            if (svc != null)
                RunFireAndForget(svc.SaveAsync(svc.ActiveSlot));
            else
                Debug.LogWarning("[SavePoint] ISaveService 未注册，跳过存档。", this);
        }

        public void OnPlayerEnterRange(Transform player) { }
        public void OnPlayerExitRange() { }

        // ── ISaveable（通过 SaveableMonoBehaviour 注册）────────────────────────
        public bool IsActivated => _isActivated;
        public void SetActivated(bool val) => _isActivated = val;

        public override void OnSave(SaveData data)
        {
            // 仅在本存档点已激活（玩家坐过）时更新复活字段。
            // 自动存档也会触发此方法，必须守卫以防止覆盖玩家真正的复活位置。
            if (!_isActivated) return;

            if (!string.IsNullOrEmpty(_currentSceneName))
                data.Player.Scene = _currentSceneName;
            if (!string.IsNullOrEmpty(_savePointId))
                data.Meta.SavePointId = _savePointId;

            if (!string.IsNullOrEmpty(_savePointId)
                && !data.World.ActivatedSavePoints.Contains(_savePointId))
                data.World.ActivatedSavePoints.Add(_savePointId);
        }

        public override void OnLoad(SaveData data)
        {
            _isActivated = !string.IsNullOrEmpty(_savePointId)
                && data.World.ActivatedSavePoints.Contains(_savePointId);
        }

        private static async void RunFireAndForget(Task task)
        {
            try { await task; }
            catch (Exception e)
            {
                Debug.LogError($"[SavePoint] 存档失败: {e.Message}\n{e.StackTrace}");
            }
        }
    }
}