using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;

namespace SoulliesFramework.General
{
    /// <summary>
    /// 静态的Addressables资源加载器，负责加载和释放资源。
    /// 警告：此类不处理依赖关系，仅管理通过它加载的资源的生命周期。
    /// </summary>
    public static class AssetLoader
    {
        // 使用字典缓存已加载资源的句柄，Key为资源的Address。
        // 这样可以防止同一资源被重复加载，并方便我们后续释放。
        private static Dictionary<string, AsyncOperationHandle> CachedHandles = new Dictionary<string, AsyncOperationHandle>();
        
        public static List<T> LoadAssetsWithLabel<T>(string label) where T : Object
        {
            return Addressables.LoadAssetsAsync<T>(label, null).WaitForCompletion().ToList();
        }
        
        public static Task<IList<T>> LoadAssetsWithLabelAsync<T>(string label) where T : Object
        {
            return Addressables.LoadAssetsAsync<T>(label, null).Task;
        }
        
        public static T LoadAsset<T>(string address) where T : Object
        {
            return Addressables.LoadAssetAsync<T>(address).WaitForCompletion();
        }
        
        
        
        /// <summary>
        /// 异步加载指定类型的资源。
        /// </summary>
        /// <typeparam name="T">要加载的资源类型 (e.g., GameObject, Sprite, AudioClip)</typeparam>
        /// <param name="address">资源的Addressable地址</param>
        /// <returns>返回加载到的资源，如果失败则返回null</returns>
        public static async Task<T> LoadAssetAsync<T>(string address) where T : Object
        {
            // 1. 检查句柄是否已经被缓存
            if (CachedHandles.TryGetValue(address, out var handle))
            {
                // 如果句柄存在，直接返回其结果
                return handle.Result as T;
            }

            // 2. 如果没有缓存，则异步加载资源
            AsyncOperationHandle<T> newHandle = Addressables.LoadAssetAsync<T>(address);

            // 3. 等待加载完成
            T result = await newHandle.Task;

            // 4. 检查加载是否成功，如果成功则缓存句柄
            if (newHandle.Status == AsyncOperationStatus.Succeeded)
            {
                // 注意：我们缓存的是通用的句柄，而不是带泛型的句柄
                CachedHandles[address] = newHandle;
                return result;
            }
            else
            {
                Debug.LogError($"[AssetLoader] Failed to load asset at address: {address}");
                return null;
            }
        }

        /// <summary>
        /// 释放指定地址的资源。
        /// </summary>
        /// <param name="address">要释放资源的Addressable地址</param>
        public static void ReleaseAsset(string address)
        {
            if (CachedHandles.TryGetValue(address, out var handle))
            {
                // 从缓存中移除
                CachedHandles.Remove(address);
                // 释放句柄，这会减少资源的引用计数
                Addressables.Release(handle);
                Debug.Log($"[AssetLoader] Released asset: {address}");
            }
            else
            {
                Debug.LogWarning($"[AssetLoader] Tried to release an asset that was not loaded through this loader: {address}");
            }
        }

        /// <summary>
        /// 释放所有通过此类加载的资源。
        /// 通常在切换场景或退出游戏时调用。
        /// </summary>
        public static void ReleaseAllAssets()
        {
            foreach (var pair in CachedHandles)
            {
                Addressables.Release(pair.Value);
            }

            CachedHandles.Clear();
            Debug.Log("[AssetLoader] All cached assets released.");
        }
    }
}