/***

  Olive - Non-Linear Video Editor
  Copyright (C) 2019 Olive Team

  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.

  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/>.

***/

#ifndef VIDEORENDERFRAMECACHE_H
#define VIDEORENDERFRAMECACHE_H

#include <QMutex>

#include "common/rational.h"
#include "render/pixelformat.h"
#include "render/videoparams.h"

OLIVE_NAMESPACE_ENTER

class VideoRenderFrameCache
{
public:
  VideoRenderFrameCache() = default;

  void Clear();

  /**
   * @brief Return whether a frame with this hash already exists
   */
  bool HasHash(const QByteArray& hash, const PixelFormat::Format &format);

  /**
   * @brief Return whether a frame is currently being cached
   */
  bool IsCaching(const QByteArray& hash);

  /**
   * @brief Check if a frame is currently being cached, and if not reserve it
   */
  bool TryCache(const QByteArray& hash);

  void SetCacheID(const QString& id);

  QByteArray TimeToHash(const rational& time) const;

  void SetHash(const rational& time, const QByteArray& hash);

  void Truncate(const rational& time);

  void RemoveHashFromCurrentlyCaching(const QByteArray& hash);

  /**
   * @brief Returns a list of frames that use a particular hash
   */
  QList<rational> FramesWithHash(const QByteArray& hash) const;

  /**
   * @brief Same as FramesWithHash() but also removes these frames from the map
   */
  QList<rational> TakeFramesWithHash(const QByteArray& hash);

  const QMap<rational, QByteArray>& time_hash_map() const;

  static QString GetFormatExtension(const PixelFormat::Format& f);

  /**
   * @brief Return the path of the cached image at this time
   */
  QString CachePathName(const QByteArray &hash, const PixelFormat::Format& pix_fmt) const;

  static bool SaveCacheFrame(const QString& filename, char *data, const VideoRenderingParams &vparam);
  void SaveCacheFrame(const QByteArray& hash, char *data, const VideoRenderingParams &vparam) const;

private:
  QMap<rational, QByteArray> time_hash_map_;

  QMutex currently_caching_lock_;
  QVector<QByteArray> currently_caching_list_;

  QString cache_id_;
};

OLIVE_NAMESPACE_EXIT

#endif // VIDEORENDERFRAMECACHE_H