using MRStore.Util;
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using UnityEngine;

namespace XRTool.Util
{
    /// <summary>
    /// 当前的状态
    /// 0代表准备下载
    /// 1代表启动下载，只有当状态为0时才会自动启动下载
    /// 2代表暂停下载，主动点击时会暂停下载，需要主动点击解除暂停状态
    /// </summary>
    public enum DownState
    {
        /// <summary>
        /// 0代表准备下载
        /// </summary>
        Prepare = 0,
        /// <summary>
        /// 1代表启动下载，只有当状态为0时才会自动启动下载
        /// </summary>
        Downing = 1,
        /// <summary>
        ///2代表暂停下载，主动点击时会暂停下载，需要主动点击解除暂停状态
        /// </summary>
        Suspend = 2
    }
    /// <summary>
    /// 下载的信息与事件
    /// </summary>
    public class DownInfo
    {
        /// <summary>
        /// 请求的地址
        /// 完整的下载地址
        /// </summary>
        public string url;
        /// <summary>
        /// 本地的下载路径
        /// </summary>
        public string localPath;
        /// <summary>
        /// 当前的下载状态
        /// </summary>
        public DownState state { get; private set; }
        /// <summary>
        /// 获得文件总大小的事件
        /// </summary>
        public event Action<DownInfo> beginDownload;
        /// <summary>
        /// 下载进度更新
        /// </summary>
        public event Action<float> downProcess;
        /// <summary>
        /// 下载完成后回调下载的路径
        /// </summary>
        public event Action<DownInfo, string> downComplete;
        /// <summary>
        /// 下载出错
        /// </summary>
        public event Action<string> downError;
        /// <summary>
        /// 下载中的文件后缀
        /// </summary>
        public const string Extension = ".downing";
        /// <summary>
        /// 文件名
        /// </summary>
        public string fileName { get; private set; }
        /// <summary>
        /// <summary>
        /// 本地临时文件名
        /// </summary>
        public string tmpFilePath { get; private set; }
        /// <summary>
        /// 本地真实文件名
        /// </summary>
        public string realFilePath { get; private set; }
        /// <summary>
        /// 文件总大小
        /// </summary>
        public long totalSize { get; private set; }
        /// <summary>
        /// 文件已下载的大小
        /// </summary>
        public long downloadedFileLen { get; private set; }
        private DownInfoHandler handler;

        /// <summary>
        /// 构造一个下载器
        /// </summary>
        /// <param name="url"></param>
        /// <param name="localPath"></param>
        public DownInfo(string url, string localPath, Action<DownInfo, string> downComplete = null,
            Action<float> downProcess = null, Action<string> downError = null, Action<DownInfo> beginDownload = null)
        {
            this.url = url;
            this.localPath = localPath;
            this.downComplete = downComplete;
            this.downProcess = downProcess;
            this.downError = downError;
            this.beginDownload = beginDownload;

            ///单纯的获取文件名+后缀
            fileName = Path.GetFileName(url);
            ///真实文件名
            realFilePath = Path.Combine(localPath, fileName);
            ///完整文件名
            tmpFilePath = realFilePath + Extension;
        }
        /// <summary>
        /// 判断是否需要下载
        /// 如果已存在真实文件，则无需下载
        /// </summary>
        /// <returns></returns>
        public bool IsNeedDown()
        {
            if (File.Exists(realFilePath))
            {
                downComplete?.Invoke(this, realFilePath);
                return false;
            }
            return true;
        }
        /// <summary>
        /// 下载失败或者出现错误后
        /// </summary>
        /// <param name="error"></param>
        public void ActiveError(string error)
        {
            state = DownState.Suspend;
            downError?.Invoke(error);
            //DataFileUtil.DelFile(tmpFilePath);
        }
        /// <summary>
        /// 获得文件的总大小 = 本地已下载+服务器剩余大小
        /// </summary>
        /// <param name="urlSize"></param>
        public void ActiveTotalLength(long urlSize)
        {
            totalSize = urlSize;
            beginDownload?.Invoke(this);
            state = DownState.Downing;
            ActiveProcess(downloadedFileLen * 1.0f / totalSize);
            ///服务端无新数据，完成下载
            if (downloadedFileLen == totalSize)
            {
                //ActiveComplete();
            }
        }
        /// <summary>
        /// 进度更新事件激活
        /// 此为文件的总进度 = 已下载的进度+当前的进度*剩余的进度比例
        /// </summary>
        /// <param name="downSize"></param>
        public void ActiveProcess(float p)
        {
            downProcess?.Invoke(p);
        }
        /// <summary>
        /// 停止下载
        /// </summary>
        public bool StopDown()
        {
            if (state == DownState.Downing)
            {
                if (handler != null && handler.webRequest != null)
                {
                    handler.webRequest.Dispose();
                    handler.ErrorDispose(null);
                }
                state = DownState.Suspend;
                handler = null;
                return true;
            }
            return false;
        }
        /// <summary>
        /// 取消下载
        /// </summary>
        public void CancelDown()
        {
            StopDown();
            DataFileUtil.DelFile(tmpFilePath);
            DataFileUtil.DelFile(realFilePath);
        }
        public void SetDownHandler(DownInfoHandler handler)
        {
            this.handler = handler;
        }
        /// <summary>
        /// 激活下载完成的事件
        /// 下载完成后，改名
        /// </summary>
        public void ActiveComplete()
        {
            ///下载完成的判断
            ///已下载的文件等于总文件大小
            if (downloadedFileLen >= totalSize)
            {
                DataFileUtil.ReNameFile(tmpFilePath, realFilePath);
                downComplete?.Invoke(this, realFilePath);
            }
        }
    }
}