FileManager.cpp

//
// Created by capone on 27.06.18.
//

#include "FileManager.h"

USING_NS_CC;

#define FILEUTILS FileUtils::getInstance()

typedef size_t(*CURL_WRITEFUNCTION_PTR)(char*, size_t, size_t, FILE*);
typedef int(*CURL_PROGRESSFUNCTION_PTR)(DownloadDelegate*, double, double, double, double);

void FileManager::startDownload(std::string &url, std::string &filePath)
{
    CURLM *curlm = curl_multi_init();
    CURL *curl = curl_easy_init();
    FILE *fp;

    if(curl) {
        downloading = true;
        fp = fopen(filePath.c_str(),"wb");

        curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
        curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);

        auto writeCallback = [](char *ptr, size_t size, size_t nmemb, FILE *stream) -> size_t {
            size_t written = fwrite(ptr, size, nmemb, stream);
            return written;
        };
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, static_cast<CURL_WRITEFUNCTION_PTR>(writeCallback));
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);

        auto progressCallback = [](DownloadDelegate *delegate,   double dltotal,   double dlnow,   double ultotal,   double ulnow) -> int {
            if (!FileManager::getInstance()->downloading) {
                CCLOG("download canceled");
                return 1;
            }

            double percent = dlnow * 100.0 / dltotal;
            //CCLOG("download progress %.0lf%%", percent);
            if (delegate) delegate->downloadTaskProgress(percent);

            return 0;
        };
        curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, static_cast<CURL_PROGRESSFUNCTION_PTR>(progressCallback));
        curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, _downloadDelegate);

        CCLOG("download started");

        curl_multi_add_handle(curlm, curl);

        Director::getInstance()->getScheduler()->schedule( [this, filePath, curlm, curl, fp](float dt) {
            int transfers;
            CURLMcode res = curl_multi_perform(curlm, &transfers);

            if (res != CURLM_OK) {
                auto error = std::string(curl_multi_strerror(res));
                CCLOG("downloading error: %s", error.c_str());
                if (_downloadDelegate) _downloadDelegate->downloadTaskError(error);
            } else {
                int msgq = 0;
                struct CURLMsg *m = curl_multi_info_read(curlm, &msgq);
                if(m && (m->msg == CURLMSG_DONE)) {
                    transfers--;

                    downloading = false;
                    fclose(fp);

                    curl_multi_remove_handle(curlm, curl);
                    curl_easy_cleanup(curl);

                    CCLOG("downloaded success");
                    if (_downloadDelegate) _downloadDelegate->downloadTaskSuccess(filePath);

                    Director::getInstance()->getScheduler()->unschedule("curl_loop", this);
                }
            }
        }, this, 0, CC_REPEAT_FOREVER, 0, false, "curl_loop");
    }
}