/**
 * Tencent is pleased to support the open source community by making Tars available.
 *
 * Copyright (C) 2016THL A29 Limited, a Tencent company. All rights reserved.
 *
 * Licensed under the BSD 3-Clause License (the "License"); you may not use this file except 
 * in compliance with the License. You may obtain a copy of the License at
 *
 * https://opensource.org/licenses/BSD-3-Clause
 *
 * Unless required by applicable law or agreed to in writing, software distributed 
 * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 
 * CONDITIONS OF ANY KIND, either express or implied. See the License for the 
 * specific language governing permissions and limitations under the License.
 */

#include "SingleFileDownloader.h"
#include "servant/TarsLogger.h"
#include "util.h"

DownloadTaskFactory* DownloadTaskFactory::_instance = new DownloadTaskFactory();

int SingleFileDownloader::download(const PatchPrx &patchPrx, const string &remoteFile, const string &localFile, const DownloadEventPtr &pPtr, std::string & sResult)
{

 vector<tars::FileInfo> vFiles;
 int ret = 0;
 
 for( int i = 0; i < 2; i ++)
 {
 try
 {
 ret = patchPrx->listFileInfo(remoteFile, vFiles);
 break;
 }
 catch(TarsException& ex)
 {
 TLOGERROR("SingleFileDownloader::download " << (remoteFile + " TarsException " + ex.what())<< endl);
 }
 }

 //1表示是文件
 if(ret != 1)
 {
 sResult = remoteFile + " is not an file";
 return -1;
 }

 if(vFiles.size() < 1)
 {
 sResult = remoteFile + " not exist";
 return -2;
 }

 tars::FileInfo fileInfo = vFiles[0];

 FILE *fp = fopen(localFile.c_str(), "wb");
 if (!fp)
 {
 sResult = localFile + " can not write";
 return -3;
 }

 //循环下载文件到本地
 vector<char> buffer;
 int pos = 0;
 int downloadRet = 0;
 bool fileEnded = false;
 while (true)
 {
 buffer.clear();

 //最多尝试两次
 for( int i = 0; i < 2; i ++)
 {
 try
 {
 downloadRet = patchPrx->download(remoteFile, pos, buffer);
 break;
 }
 catch(TarsException& ex)
 {
 TLOGERROR("SingleFileDownloader::download "<< (remoteFile + " TarsException " + ex.what()) << endl);
 }
 }

 if (downloadRet < 0)
 {
 TLOGERROR("SingleFileDownloader::download " << "|downloadRet:" << downloadRet << "|remoteFile:" << remoteFile << endl);
 sResult = remoteFile + " download from tarspatch error " + TC_Common::tostr(downloadRet);
 ret = downloadRet - 100;
 break;
 }
 else if (downloadRet == 0)
 {
 size_t r = fwrite((void*)&buffer[0], 1, buffer.size(), fp);
 if (r == 0)
 {
 TLOGERROR("SingleFileDownloader::download fwrite file '" + localFile + "' error!" << endl);
 sResult = "fwrite file '" + localFile + "' error!";
 ret = -5;
 break;
 }
 pos += r;
 if(pPtr)
 {
 pPtr->onDownloading(fileInfo, pos);
 }
 }
 else if (downloadRet == 1)
 {
 TLOGDEBUG("SingleFileDownloader::download load succ " << remoteFile << "|pos:"<<pos<<endl);
 ret = 0;
 fileEnded = true;
 break;
 }
 }

 if(!fileEnded)
 {
 ret = -6;
 sResult = remoteFile + " not end";
 }

 fclose(fp);

 return ret;
}