OpenSpace/include/openspace/util/httprequest.h

/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2017                                                               *
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 * or substantial portions of the Software.                                              *
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#ifndef __OPENSPACE_CORE___HTTPREQUEST___H__
#define __OPENSPACE_CORE___HTTPREQUEST___H__

#include <ghoul/filesystem/file.h>
#include <ghoul/filesystem/directory.h>

#include <functional>
#include <memory>
#include <string>
#include <vector>

namespace openspace {
    
namespace curlfunctions {
    size_t writeCallback(char *ptr,
                         size_t size,
                         size_t nmemb,
                         void *userdata);

    int progressCallback(void *clientp,
                         int64_t dltotal,
                         int64_t dlnow,
                         int64_t ultotal,
                         int64_t ulnow);
}

// Synchronous http request
class HttpRequest {
public:
    enum class ReadyState : unsigned int {
        Unsent,
        Loading,
        ReceivedHeaders,
        Fail,
        Success
    };

    struct Progress {
        bool totalBytesKnown = false;
        size_t totalBytes = 0;
        size_t downloadedBytes = 0;
    };

    struct Data {
        char* buffer;
        size_t size;
    };

    using ReadyStateChangeCallback = std::function<void(ReadyState)>;
    using ProgressCallback = std::function<int(Progress)>;
    using DataCallback = std::function<size_t(Data)>;

    struct RequestOptions {
        int requestTimeoutSeconds; // 0 for no timeout
    };

    HttpRequest(std::string url);

    void onReadyStateChange(ReadyStateChangeCallback cb);
    void onProgress(ProgressCallback cb);
    void onData(DataCallback cb);

    void perform(RequestOptions opt);

private:
    void setReadyState(ReadyState state);

    std::string _url;

    ReadyStateChangeCallback _onReadyStateChange;
    ProgressCallback _onProgress;
    DataCallback _onData;

    ReadyState _readyState;
    Progress _progress;
    RequestOptions _options;
    
    friend size_t curlfunctions::writeCallback(
                                char *ptr,
                                size_t size,
                                size_t nmemb,
                                void *userdata);

    friend int curlfunctions::progressCallback(void *clientp,
                                               int64_t dltotal,
                                               int64_t dlnow,
                                               int64_t ultotal,
                                               int64_t ulnow);
};
    
class HttpMemoryDownload {
public:
    HttpMemoryDownload(std::string url);
    
    void onReadyStateChange(HttpRequest::ReadyStateChangeCallback cb);
    void onProgress(HttpRequest::ProgressCallback cb);
    
    void download(HttpRequest::RequestOptions opt);
    
    const std::vector<char>& downloadedData();

private:
    HttpRequest _httpRequest;
    std::vector<char> _downloadedData;
};

class HttpFileDownload {
public:
    HttpFileDownload(std::string url, std::string destinationPath);
    
    void onReadyStateChange(HttpRequest::ReadyStateChangeCallback cb);
    void onProgress(HttpRequest::ProgressCallback cb);
    
    void download(HttpRequest::RequestOptions opt);

private:
    HttpRequest _httpRequest;
    std::string _destination;
};
    

} // namespace openspace

#endif // __OPENSPACE_CORE___HTTPREQUEST___H__