using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Windows.Forms;
using Aliyun.OSS;
using Aliyun.OSS.Common;

namespace _1200gFtp
{
    /// <summary>
    /// 阿里云上传下载数据类
    /// </summary>
    public class OssUnity
    {
        public readonly OssClient _client;
        const string endpoint = "http://oss-cn-beijing.aliyuncs.com";
        //北京科麦迪账号下的 华东2 上海  oss
        const string accessId = "LTAI5tA3YFzqR2qHSLYZP68T";
        const string accessKey = "efjTmIWXCGcJO4vmnHnNhKsuXbiVo5";

        public OssUnity()
        {

            _client = new OssClient(endpoint, accessId, accessKey);
        }

        /// <summary>
        /// Bucket数据容器,出错返回错误信息.
        /// </summary>
        /// <param name="bucketName">Bucket名称</param>
        /// <param name="msg">错误信息</param>
        /// <returns>是否执行成功</returns>
        public bool CreateBucket(string bucketName, out string msg)
        {
            bool reslut = true; 
             msg = string.Empty;
            try
            {
                var buckets = _client.ListBuckets();
                if (buckets.All(b => b.Name != bucketName))
                {
                    _client.CreateBucket(bucketName);
                }
            }
            catch (OssException ex)
            {
                reslut = false;
                msg = ex.Message;
            }
            return reslut;
        }

        /// <summary>
        /// 上传文件到Bucket容器
        /// </summary>
        /// <param name="bucketName">Bucket容器</param>
        /// <param name="key">Key值</param>
        /// <param name="path">文件路径</param>
        /// <returns>返回MD5值</returns>
        public string PutObject(String bucketName, String key, String path)
        {
            using (var fs = File.Open(path, FileMode.Open))
            {
                var metadata = new ObjectMetadata { ContentLength = fs.Length };
                var result = _client.PutObject(bucketName, key, fs, metadata);
                return result.ETag;
            }
        }
        /// <summary>
        /// 下载数据
        /// </summary>
        /// <param name="pb">进度条</param>
        /// <param name="lbl">提示文本框</param>
        /// <param name="saveFileName">文件保存路径</param>
        /// <param name="bucketName">bucket名称</param>
        /// <param name="key">KEY值</param>
        /// <returns></returns>
        public bool DownloadData(ProgressBar pb, Label lbl, string saveFileName, string bucketName, string key)
        {
            bool result = false;
            short ticks = 0;
            try
            {
                if (pb != null)
                {
                    //if (pb.InvokeRequired)
                    //{
                    //    pb.BeginInvoke((Action)(() =>
                    //    {
                    //        pb.Maximum = 100;
                    //    }));
                    //}
                    //else
                    pb.Maximum = 100;
                }
                var obj = _client.GetObject(bucketName, key);
                using (var requestStream = obj.Content)
                {
                    var buf = new byte[1024];
                    using (var fs = File.Open(saveFileName, FileMode.OpenOrCreate))
                    {
                        var len = 0;
                        while ((len = requestStream.Read(buf, 0, 1024)) != 0)
                        {
                            fs.Write(buf, 0, len);
                            float percent = fs.Length / (float)obj.Metadata.ContentLength;
                            var n = (int)Math.Ceiling(percent * 100);
                            Application.DoEvents();

                            if (pb != null)
                            {
                                pb.Value = n <= 100 ? n : 100;
                                //pb.Refresh();
                            }
                            if (lbl != null)
                            {
                                lbl.Text = percent.ToString("00.00%");
                                //lbl.Refresh();
                            }
                        }
                    }
                }
                result = true;
            }
            catch (Exception ex)
            {
                ticks++;
                if (ticks < 3)
                {
                    DownloadData(pb, lbl, saveFileName, bucketName, key);
                }
                else
                {
                  //  Watching.Write(@"下载出错：", ex);
                    if (lbl != null)
                        lbl.Text = "下载出错，请稍后再试！";
                }
            }
            return result;
        }

        /// <summary>
        /// 判断OSS上的文件是否存在
        /// </summary>
        /// <param name="bucketName">BUCKET NAME</param>
        /// <param name="key">KEY</param>
        /// <returns></returns>
        public bool Exists(string bucketName, string key)
        {
            bool flag = true;
            try
            {
                OssObject obj = _client.GetObject(bucketName, key);
                obj.Dispose();
            }
            catch (Exception)
            {
                flag = false;
            }
            return flag;
        }

        ///  <summary>
        /// 下载oss上的文件
        ///  </summary>
        ///  <param name="bucketName"></param>
        ///  <param name="key"></param>
        /// <param name="localFilePath"></param>
        public void GetObject(String bucketName, string key, string localFilePath)
        {
            var object1 = _client.GetObject(bucketName, key);
            using (var requestStream = object1.Content)
            {
                var buf = new byte[1024];
                var fs = File.Open(localFilePath, FileMode.OpenOrCreate);
                int len;
                while ((len = requestStream.Read(buf, 0, 1024)) != 0)
                {
                    fs.Write(buf, 0, len);
                }
                fs.Close();
            }
        }

    }
}