/***

  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 AUDIORENDERER_H
#define AUDIORENDERER_H

#include <QLinkedList>
#include <QOpenGLTexture>

#include "node/node.h"
#include "render/pixelformat.h"
#include "render/rendermodes.h"
#include "audiorendererthread.h"

/**
 * @brief A multithreaded PCM audio renderer
 */
class AudioRendererProcessor : public Node
{
  Q_OBJECT
public:
  /**
   * @brief Renderer Constructor
   *
   * Constructing a Renderer object will not start any threads/backend on its own. Use Start() to do this and Stop()
   * when the Renderer is about to be destroyed.
   */
  AudioRendererProcessor();

  virtual QString Name() override;
  virtual QString Category() override;
  virtual QString Description() override;
  virtual QString id() override;

  void SetCacheName(const QString& s);

  virtual void Release() override;

  virtual void InvalidateCache(const rational &start_range, const rational &end_range, NodeInput *from = nullptr) override;

  void SetTimebase(const rational& timebase);

  /**
   * @brief Set parameters of the Renderer
   *
   * The Renderer owns the buffers that are used in the rendering process and this function sets the kind of buffers
   * to use. The Renderer must be stopped when calling this function.
   *
   * @param width
   *
   * Buffer width
   *
   * @param height
   *
   * Buffer height
   *
   * @param format
   *
   * Buffer pixel format
   */
  void SetParameters(const int& sample_rate,
                     const uint64_t& channel_layout,
                     const olive::SampleFormat& 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);

  /**
   * @brief Return current instance of a RenderThread (or nullptr if there is none)
   *
   * This function attempts a dynamic_cast on QThread::currentThread() to RendererThread, which will return nullptr if
   * the cast fails (e.g. if this function is called from the main thread rather than a RendererThread).
   */
  static AudioRendererThreadBase* CurrentThread();

  static AudioRendererParams* CurrentInstance();

  NodeInput* texture_input();

  NodeInput* length_input();

  NodeOutput* texture_output();

protected:
  virtual QVariant Value(NodeOutput* output, const rational& time) override;

private:
  struct HashTimeMapping {
    rational time;
    QByteArray hash;
  };

  /**
   * @brief Allocate and start the multithreaded backend
   */
  void Start();

  /**
   * @brief Terminate and deallocate the multithreaded backend
   */
  void Stop();

  /**
   * @brief Internal function for generating the cache ID
   */
  void GenerateCacheIDInternal();

  /**
   * @brief Function called when there are frames in the queue to cache
   *
   * This function is NOT thread-safe and should only be called in the main thread.
   */
  void CacheNext();

  bool ShouldPushTexture(const rational &time);

  /**
   * @brief Internal list of RenderProcessThreads
   */
  QVector<AudioRendererThreadPtr> threads_;

  /**
   * @brief Internal variable that contains whether the Renderer has started or not
   */
  bool started_;

  NodeInput* texture_input_;

  NodeInput* length_input_;

  NodeOutput* texture_output_;

  rational timebase_;
  double timebase_dbl_;

  int sample_rate_;
  uint64_t channel_layout_;
  olive::SampleFormat format_;

  QLinkedList<rational> cache_queue_;
  QString cache_name_;
  qint64 cache_time_;
  QString cache_id_;

  bool caching_;

  bool starting_;

private slots:

};

#endif // AUDIORENDERER_H