///////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////断点续存的方式下载网络资源/////////////////////////////////////////
/////////////////////////TODO:UI显示下载进度///暂时使用打印替代（平板不需要）//////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.Networking;

public class DownloadAssets : MonoBehaviour
{
    public static DownloadAssets Instance;
    //五亿字节为一段  0.1G  100mb
    double loadedBytes = 100000000;

    /// <summary>
    /// 存放正在下载资源的UWR事件
    /// </summary>
    internal Dictionary<string, UnityWebRequest> AssetsUWR = new Dictionary<string, UnityWebRequest>();
    /// <summary>
    /// 创建新的资源图标
    /// </summary>
    internal UnityEvent<Assets,string> CreateAssetcell = new UnityEvent<Assets, string>();
    /// <summary>
    /// 更新资源图标
    /// </summary>
    internal UnityEvent<Assets, string> UpdateAssetcell = new UnityEvent<Assets, string>();
    /// <summary>
    /// 删除资源图标
    /// </summary>
    internal UnityEvent<Assets, string> DeleteAssetcell = new UnityEvent<Assets, string>();

    void Awake()
    {
        if (Instance == null)
            Instance = this;
    }

    /// <summary>
    /// 下载资源
    /// </summary>
    /// <param name="fullUrl">资源url</param>
    /// <param name="savePath">本地存放位置</param>
    /// <param name="assets">资源信息</param>
    /// <param name="isAdded">是否是新增资源</param>
    /// <param name="isIcon">是否是封面</param>
    public void DownLoad(string fullUrl, string savePath, Assets assets, bool isAdded, bool isIcon)
    {
        //完整的接口
        fullUrl = WebNet.DownAssetsUrl + fullUrl;
        //Debug.Log(fullUrl);
        StartCoroutine(RenewDownLoad(fullUrl, savePath, assets, isAdded, isIcon));
    }


    /// <summary>
    /// 断点续存
    /// </summary>
    /// <param name="fullUrl">资源url</param>
    /// <param name="savePath">本地存放位置</param>
    IEnumerator RenewDownLoad(string fullUrl, string savePath, Assets assets, bool isAdded, bool isIcon)
    {
        long countLength;
        using (UnityWebRequest uwrGetCount = UnityWebRequest.Head(fullUrl))
        {
            yield return uwrGetCount.SendWebRequest();
            //获取资源字节长度
            long.TryParse(uwrGetCount.GetResponseHeader("Content-Length"), out countLength);
            //Debug.Log($"{savePath}:{countLength}");
        }
        //long countLength = assets.file_size;
        ////Debug.LogError(fullUrl);
        //if (assets.file_size > 1000000)
        //{
        //    using (UnityWebRequest uwrGetCount = UnityWebRequest.Head(fullUrl))
        //    {
        //        yield return uwrGetCount.SendWebRequest();
        //        //获取资源字节长度
        //        countLength = long.Parse(uwrGetCount.GetResponseHeader("Content-Length"));
        //        //Debug.Log($"{savePath}:{countLength}");
        //    }
        //}

        using (UnityWebRequest unityWebRequest = UnityWebRequest.Get(fullUrl))
        {
            //append设置为true文件写入方式为接续写入，不覆盖原文件。
            unityWebRequest.downloadHandler = new DownloadHandlerFile(savePath, true);
            //创建文件
            FileInfo file = new FileInfo(savePath);
            string filename = Path.GetFileName(savePath);//资源名字
            if (!AssetsUWR.ContainsKey(filename))
                AssetsUWR.Add(filename, unityWebRequest);
            //当前下载的文件长度
            long fileLength = file.Length;
            //请求网络数据从第fileLength到最后的字节
            unityWebRequest.SetRequestHeader("Range", $"bytes={fileLength}-");//设置Range值

            if (!string.IsNullOrEmpty(unityWebRequest.error))
            {
                Debug.LogError($"下载失败{unityWebRequest.error}");
            }

            string jsonPath = $"{Path.GetDirectoryName(savePath)}/{assets.resource_name}.json";
            //Debug.Log(jsonPath);
            double currProgress = 0;
            if (fileLength < countLength)
            {
                unityWebRequest.SendWebRequest();
                while (!unityWebRequest.isDone)
                {
                    if (File.Exists(jsonPath))
                    {
                        File.Delete(jsonPath);
                    }

                    double lastProgress = (double)fileLength / countLength;//上次下载的进度
                    //Debug.Log($"{savePath}上次下载：{(lastProgress * 100).ToString("0.00")}% ");
                    double newProgress = unityWebRequest.downloadProgress;
                    currProgress = lastProgress + newProgress * (1 - lastProgress);
                    //Debug.Log($"{savePath}已经下载：{(currProgress * 100).ToString("0.00")}% ");

                    if (savePath.Contains("mp4"))
                    {
                        //更新进度条
                        //UpdateVideoProgressUIEvent.Invoke(filename, currProgress);
                    }
                    else if (savePath.Contains("apk"))
                    {
                        //更新进度条
                        //UpdateAppProgressUIEvent.Invoke(filename, currProgress);
                    }
                    else
                    {
                        //其他资源更新进度条
                    }

                    //超过一定的字节关闭现在的协程，开启新的协程，将资源分段下载
                    if (unityWebRequest.downloadedBytes >= loadedBytes)
                    {
                        Coroutine coroutine = StartCoroutine(RenewDownLoad(fullUrl, savePath, assets, isAdded, isIcon));
                        StopCoroutine(coroutine);
                        //如果 UnityWebRequest 在进行中，就停止。
                        unityWebRequest.Abort();
                        AssetsUWR.Remove(filename);
                        if (!string.IsNullOrEmpty(unityWebRequest.error))
                        {
                            Debug.LogError($"{filename}下载失败:{unityWebRequest.error}");
                        }
                        Debug.Log($"开启新的携程继续下载{filename}");
                        yield return StartCoroutine(RenewDownLoad(fullUrl, savePath, assets, isAdded, isIcon));
                    }

                    yield return null;
                }
            }
            else
            {
                //资源是完整的
                DoneRecordInfo(savePath, assets, isIcon);
            }

            if (unityWebRequest.downloadHandler.isDone)
            {
                DoneRecordInfo(savePath, assets, isAdded, isIcon);
            }
        }
    }


    /// <summary>
    /// 资源是完整的,直接记录下载完成信息
    /// </summary>
    void DoneRecordInfo(string savePath, Assets assets, bool isIcon)
    {
        AssetsUWR.Remove(Path.GetFileName(savePath));
        if (isIcon)
            return;//如果下载的是封面，则不记录
        RecordDownloaddoneAssetsinfo(assets);
    }
    /// <summary>
    /// 下载完成记录信息
    /// </summary>
    void DoneRecordInfo(string savePath, Assets assets, bool isAdded, bool isIcon)
    {
        AssetsUWR.Remove(Path.GetFileName(savePath));

        string extension = Path.GetExtension(savePath).ToLower();

        switch (assets.type)//1:apk  2:video  3:image   4:file  5:maps  6:pc应用
        {
            case 1:
                if (isIcon)
                {
                    //Debug.Log($"封面图片：{assets.resource_name}下载完成");
                    if (isAdded)//资源是新增
                    {
                        Debug.Log("创建资源封面");
                        CreateAssetcell.Invoke(assets, savePath);
                    }
                    else//资源是更新
                    {
                        Debug.Log("更改资源封面");
                        UpdateAssetcell.Invoke(assets, savePath);
                    }
                    return;
                }
                else
                {
                    Debug.Log($"app资源：{assets.resource_name}下载完成");
                    //关闭下载进度条
                    PicoAPI._Instance.UnInstallApp(assets.brief);
                    GameTools.Share.Delay(5f, () =>
                    {
                        PicoAPI._Instance.InstallApk(savePath);
                    });
                }
                break;
            case 2:
                if (isIcon)
                {
                    //Debug.Log($"封面图片：{assets.resource_name}下载完成");
                    if (isAdded)//资源是新增
                    {
                        Debug.Log("创建资源封面");
                        CreateAssetcell.Invoke(assets, savePath);
                    }
                    else//资源是更新
                    {
                        Debug.Log("更改资源封面");
                        UpdateAssetcell.Invoke(assets, savePath);
                    }
                    return;
                }
                else
                {
                    Debug.Log($"mp4资源：{assets.resource_name}下载完成");
                    //关闭下载进度条
                }
                break;
            case 3:
                Debug.Log($"图片资源：{assets.resource_name}下载完成");
                //关闭下载进度条
                break;
            case 4:
                Debug.Log($"文件资源：{assets.resource_name}下载完成");
                //关闭下载进度条
                break;
            case 5:
                Debug.Log($"地图资源：{assets.resource_name}下载完成");
                //关闭下载进度条
                break;
            case 6:
                if (isIcon)
                {
                    //Debug.Log($"封面图片：{assets.resource_name}下载完成");
                    if (isAdded)//资源是新增
                    {
                        Debug.Log("创建资源封面");
                        CreateAssetcell.Invoke(assets, savePath);
                    }
                    else//资源是更新
                    {
                        Debug.Log("更改资源封面");
                        UpdateAssetcell.Invoke(assets, savePath);
                    }
                    return;
                }
                else
                {
                    Debug.Log($"pc应用资源：{assets.resource_name}下载完成");
                    //关闭下载进度条
                }
                break;
            default:
                //其他未知资源
                Debug.Log($"其他资源：{assets.resource_name}下载完成");
                break;
        }
        RecordDownloaddoneAssetsinfo(assets);
    }



    /// <summary>
    /// 记录下载完成的资源信息
    /// </summary>
    public void RecordDownloaddoneAssetsinfo(Assets assets)
    {
        string json = JsonUtility.ToJson(assets);
        byte[] bytes = Encoding.UTF8.GetBytes(json);
        string path = $"{Config.AssetsInfoPath}/{assets.resource_name}.json";
        GameTools.WriteFile(path, bytes);
    }

    private void OnDestroy()
    {
        foreach (var item in AssetsUWR.Values)
        {
            item.Abort();
        }
    }
}