using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.Networking;
using XFramework;

public static  class OutSpriteLoader 
{

    public static Dictionary<string, Sprite> loadedSpriteDic = new Dictionary<string, Sprite>();
    public static Dictionary<string, Texture2D> loadedTextureDic = new Dictionary<string, Texture2D>();

    //public async Task<Texture> LoadTexture(string path) 
    //{
    //    //if (OutTextureManager.loadedTexture.ContainsKey(path))
    //    //    loadedAction?.Invoke(OutTextureManager.loadedTexture[path]);
    //    //else
    //    //{
    //        var request = UnityWebRequestTexture.GetTexture(path);
    //        await request;
    //        Texture texture=null;
    //        if (DownloadHandlerTexture.GetContent(request) != null)
    //        {
    //            texture = DownloadHandlerTexture.GetContent(request);
    //            OutTextureManager.loadedTexture.Add(path, texture);
    //        }
    //        else
    //        {
    //            Debug.Log("图片加载失败，请确认名称是否正确");
    //        }
    //        //loadedAction?.Invoke(texture);
    //    //}
    //}

    /// <summary>
    /// 加载多张图片
    /// </summary>
    /// <param name="paths"></param>
    /// <returns></returns>
    public static async Task<Texture2D []> LoadTexture(string [] paths)
    {
        Texture2D[] textures = new Texture2D[paths.Length];
        Dictionary<string, Task<Texture2D>> allTasksDic = new Dictionary<string, Task<Texture2D>>();
        for (int i = 0; i < paths.Length; i++)
        {
            if (string.IsNullOrEmpty(paths[i]))
            {
                textures[i] = default(Texture2D);
            }
            else if (loadedTextureDic.ContainsKey(paths[i]))
            {
                textures[i] = loadedTextureDic[paths[i]];
            }
            else if(!allTasksDic.ContainsKey(paths[i]))
            {
                allTasksDic.Add(paths[i], LoadAsyncTexture(paths[i]));
            }
        }
        await Task.WhenAll(allTasksDic.Values);//等待所有需要加载的图片完成加载
        for (int i = 0; i < paths.Length; i++)
        {
            if (!string.IsNullOrEmpty(paths[i]) && allTasksDic.ContainsKey(paths[i]))
                textures[i] = allTasksDic[paths[i]].Result;
        }
        return textures;
    }

    /// <summary>
    /// 加载一张图片
    /// </summary>
    /// <param name="path"></param>
    /// <returns></returns>
    public static async Task<Texture2D> LoadTexture(string path)
    {
        if (string.IsNullOrEmpty(path))
            return default(Texture2D);
        if (loadedTextureDic.ContainsKey(path))
            return loadedTextureDic[path];
        var task = LoadAsyncTexture(path);
        Task<Texture2D> t = await Task.WhenAny(task);
        return t.Result;
    }


    public static async Task<Sprite[]> LoadSprites(string[] paths)
    {
        Sprite[] sprites = new Sprite[paths.Length];
        Dictionary<string, Task<Sprite>> allTasksDic = new Dictionary<string, Task<Sprite>>();
        for (int i = 0; i < paths.Length; i++)
        {
            if (string.IsNullOrEmpty(paths[i]))
            {
                sprites[i] = GetDefultSprite();
            }
            else if (loadedSpriteDic.ContainsKey(paths[i]))
            {
                sprites[i] = loadedSpriteDic[paths[i]];
            }
            else if (!allTasksDic.ContainsKey(paths[i]))
            {
                allTasksDic.Add(paths[i], LoadAsyncSprite(paths[i]));
            }
        }
        await Task.WhenAll(allTasksDic.Values);//等待所有需要加载的图片完成加载
        for (int i = 0; i < paths.Length; i++)
        {
            if (!string.IsNullOrEmpty(paths[i]) && allTasksDic.ContainsKey(paths[i]))
                sprites[i] = allTasksDic[paths[i]].Result;
        }
        return sprites;
    }

    public static async Task<Sprite> LoadSprite(string path)
    {
        if (string.IsNullOrEmpty(path))//无效路径返回一个默认的图标
        {
            return GetDefultSprite();
        }
        if (loadedSpriteDic.ContainsKey(path))
            return loadedSpriteDic[path];
        var task = LoadAsyncSprite(path);
        Task<Sprite> t = await Task.WhenAny(task);
        return t.Result;
    }

    /// <summary>
    /// 获取一个默认的Sprite"?" 避免出现空图标 
    /// </summary>
    /// <returns></returns>
    static Sprite GetDefultSprite()
    {
        if (!loadedSpriteDic.ContainsKey("defaultSprite"))
        {
            Texture2D tex = new Texture2D(2, 2);
            tex.LoadImage(null);
            Vector2 pivot = new Vector2(0.5f, 0.5f);
            Sprite sprite = Sprite.Create(tex, new Rect(0.0f, 0.0f, tex.width, tex.height), pivot, 100.0f);
            loadedSpriteDic.Add("defaultSprite", sprite);
        }
        return loadedSpriteDic["defaultSprite"];
    }


    static async Task<Sprite> LoadAsyncSprite(string url)
    {
        //string path = Path.Combine(Application.streamingAssetsPath, url + end);
        var getRequest = UnityWebRequest.Get(url);
        await getRequest.SendWebRequest();
        byte[] imgData = getRequest.downloadHandler.data;
        Texture2D tex = new Texture2D(2, 2);
        tex.LoadImage(imgData);
        Vector2 pivot = new Vector2(0.5f, 0.5f);
        Sprite sprite = Sprite.Create(tex, new Rect(0.0f, 0.0f, tex.width, tex.height), pivot, 100.0f);
        loadedSpriteDic.Add(url, sprite);
        return sprite;
    }


    static async Task<Texture2D> LoadAsyncTexture(string url)
    {
        //string path = Path.Combine(Application.streamingAssetsPath, url + end);
        var getRequest = UnityWebRequestTexture.GetTexture(url);
        await getRequest.SendWebRequest();
        Texture2D tex = DownloadHandlerTexture.GetContent(getRequest);
        loadedTextureDic.Add(url, tex);
        return tex;
    }

}