/*
 * Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
 *
 * This file is part of ZLMediaKit(https://github.com/xia-chu/ZLMediaKit).
 *
 * Use of this source code is governed by MIT license that can be found in the
 * LICENSE file in the root of the source tree. All contributing project authors
 * may be found in the AUTHORS file in the root of the source tree.
 */

#include "HttpDownloader.h"
#include "Util/File.h"
#include "Util/MD5.h"
using namespace toolkit;

namespace mediakit {

HttpDownloader::HttpDownloader() {}

HttpDownloader::~HttpDownloader() {
    closeFile();
}

void HttpDownloader::startDownload(const string &url, const string &filePath, bool bAppend) {
    _filePath = filePath;
    if (_filePath.empty()) {
        _filePath = exeDir() + "HttpDownloader/" + MD5(url).hexdigest();
    }
    _saveFile = File::create_file(_filePath.data(), bAppend ? "ab" : "wb");
    if (!_saveFile) {
        auto strErr = StrPrinter << "打开文件失败:" << filePath << endl;
        throw std::runtime_error(strErr);
    }
    _bDownloadSuccess = false;
    if (bAppend) {
        auto currentLen = ftell(_saveFile);
        if (currentLen) {
            //最少续传一个字节，怕遇到http 416的错误
            currentLen -= 1;
            fseek(_saveFile, -1, SEEK_CUR);
        }
        addHeader("Range", StrPrinter << "bytes=" << currentLen << "-" << endl);
    }
    setMethod("GET");

    sendRequest(url);
}

ssize_t HttpDownloader::onResponseHeader(const string &status, const HttpHeader &headers) {
    if (status != "200" && status != "206") {
        //失败
        shutdown(SockException(Err_shutdown, StrPrinter << "Http Status:" << status));
    }
    //后续全部是content
    return -1;
}

void HttpDownloader::onResponseBody(const char *buf, size_t size, size_t recvedSize, size_t totalSize) {
    if (_saveFile) {
        fwrite(buf, size, 1, _saveFile);
    }
}

void HttpDownloader::onResponseCompleted() {
    closeFile();
    // InfoL << "md5Sum:" << getMd5Sum(_filePath);
    _bDownloadSuccess = true;
    if (_onResult) {
        _onResult(Err_success, "success", _filePath);
        _onResult = nullptr;
    }
}

void HttpDownloader::onDisconnect(const SockException &ex) {
    closeFile();
    if (!_bDownloadSuccess) {
        File::delete_file(_filePath.data());
    }
    if (_onResult) {
        _onResult(ex.getErrCode(), ex.what(), _filePath);
        _onResult = nullptr;
    }
}

void HttpDownloader::closeFile() {
    if (_saveFile) {
        fflush(_saveFile);
        fclose(_saveFile);
        _saveFile = nullptr;
    }
}

} /* namespace mediakit */