/**
 * Orthanc - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
 * Department, University Hospital of Liege, Belgium
 * Copyright (C) 2017-2020 Osimis S.A., Belgium
 *
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * In addition, as a special exception, the copyright holders of this
 * program give permission to link the code of its release with the
 * OpenSSL project's "OpenSSL" library (or with modified versions of it
 * that use the same license as the "OpenSSL" library), and distribute
 * the linked executables. You must obey the GNU General Public License
 * in all respects for all of the code used other than "OpenSSL". If you
 * modify file(s) with this exception, you may extend this exception to
 * your version of the file(s), but you are not obligated to do so. If
 * you do not wish to do so, delete this exception statement from your
 * version. If you delete this exception statement from all source files
 * in the program, then also delete it here.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 **/


#pragma once

#include "BufferHttpSender.h"

#include "../Compatibility.h"

#include <memory>  // For std::unique_ptr

namespace Orthanc
{
  class ORTHANC_PUBLIC HttpStreamTranscoder : public IHttpStreamAnswer
  {
  private:
    IHttpStreamAnswer& source_;
    CompressionType    sourceCompression_;
    uint64_t           bytesToSkip_;
    uint64_t           skipped_;
    uint64_t           currentChunkOffset_;
    bool               ready_;

    std::unique_ptr<BufferHttpSender>  uncompressed_;

    void ReadSource(std::string& buffer);

    HttpCompression SetupZlibCompression(bool deflateAllowed);

  public:
    HttpStreamTranscoder(IHttpStreamAnswer& source,
                         CompressionType compression) : 
      source_(source),
      sourceCompression_(compression),
      bytesToSkip_(0),
      skipped_(0),
      currentChunkOffset_(0),
      ready_(false)
    {
    }

    // This is the first method to be called
    virtual HttpCompression SetupHttpCompression(bool gzipAllowed,
                                                 bool deflateAllowed);

    virtual bool HasContentFilename(std::string& filename)
    {
      return source_.HasContentFilename(filename);
    }

    virtual std::string GetContentType()
    {
      return source_.GetContentType();
    }

    virtual uint64_t GetContentLength();

    virtual bool ReadNextChunk();

    virtual const char* GetChunkContent();

    virtual size_t GetChunkSize();
  };
}