/***

  Olive - Non-Linear Video Editor
  Copyright (C) 2022 Olive Team
  Modifications Copyright (C) 2025 mikesolar

  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 OAK_PREVIEWAUDIODEVICE_H
#define OAK_PREVIEWAUDIODEVICE_H

#include <olive/core/render/audioparams.h>

#include <atomic>

#include "previewautocacher.h"

namespace olive
{

class PreviewAudioDevice : public QIODevice {
	Q_OBJECT
public:
	PreviewAudioDevice(QObject *parent = nullptr);

	virtual ~PreviewAudioDevice() override;

	void start_queuing();

	virtual bool isSequential() const override;

	virtual qint64 readData(char *data, qint64 max_size) override;

	virtual qint64 writeData(const char *data, qint64 length) override;

	// Derives the frame size from the audio format (bytes per sample per
	// channel * channel count). Until params are set, bytes_per_frame()
	// reports 0, i.e. "unknown".
	void set_params(const core::AudioParams &params);

	int bytes_per_frame() const
	{
		return bytes_per_frame_;
	}

	void set_bytes_per_frame(int b)
	{
		bytes_per_frame_ = b;
	}

	void set_notify_interval(qint64 i)
	{
		notify_interval_ = i;
	}

	void clear();

	/**
	 * @brief Frames consumed by the audio output callback
	 *
	 * Counted in the callback itself so underrun (zero-filled) frames are
	 * included, making the value usable as a playback clock.
	 */
	void add_output_frames(qint64 frame_count)
	{
		output_frames_consumed_.fetch_add(frame_count);
	}

	qint64 output_frames_consumed() const
	{
		return output_frames_consumed_.load();
	}

	void reset_output_frames()
	{
		output_frames_consumed_.store(0);
	}

signals:
	void notify();

private:
	QMutex lock_;

	QByteArray buffer_;

	int bytes_per_frame_;

	qint64 notify_interval_;

	qint64 bytes_read_;

	std::atomic<qint64> output_frames_consumed_{0};
};

}

#endif // OAK_PREVIEWAUDIODEVICE_H