using System;
using System.Collections.Generic;
using System.IO;
using UnityEngine;
using XWorld.Framework;

namespace XGame.MiniGame
{
    // IAssetLoader over 已下载的小游戏资源 AB（manifest.Assets）；首次 Load 时开全部包并缓存，退出统一卸载
    public sealed class MiniGameAssetLoader : IAssetLoader
    {
        private readonly string _localDir;
        private readonly List<string> _abNames;
        private readonly List<AssetBundle> _opened = new List<AssetBundle>();
        private bool _openedAll;

        public MiniGameAssetLoader(string localDir, MiniGameManifest manifest)
        { _localDir = localDir; _abNames = manifest.Assets; }

        // path: 打包时的资产路径（如 "Assets/MiniGames/RockPaperScissors/res/UI/Prefab/UI_RockPaperScissors.prefab"）
        // 或裸资产名（"UI_RockPaperScissors"）；找不到回调 null。
        public void Load(string path, Action<object> onLoaded)
        {
            EnsureOpened();
            foreach (var ab in _opened)
            {
                UnityEngine.Object obj = ab.LoadAsset(path);
                if (obj == null) obj = ab.LoadAsset(Path.GetFileNameWithoutExtension(path));
                if (obj != null) { onLoaded?.Invoke(obj); return; }
            }
            Debug.LogError("[MiniGameAssetLoader] 资产未找到: " + path);
            onLoaded?.Invoke(null);
        }

        // 小游戏退出时由 MiniGameHost 调用；true=连已实例化引用的资产一起卸
        public void UnloadAll()
        {
            foreach (var ab in _opened) if (ab != null) ab.Unload(true);
            _opened.Clear();
            _openedAll = false;
        }

        private void EnsureOpened()
        {
            if (_openedAll) return;
            _openedAll = true;
            foreach (var name in _abNames)
            {
                string p = _localDir + name;
                if (!File.Exists(p)) { Debug.LogError("[MiniGameAssetLoader] 资源 AB 缺失: " + p); continue; }
                var ab = MiniGamePlatform.LoadAssetBundle(p);
                if (ab == null) { Debug.LogError("[MiniGameAssetLoader] 资源 AB 打开失败: " + p); continue; }
                _opened.Add(ab);
            }
        }
    }
}