/**
 * Copyright 2013 (c) Anna Schumaker.
 */
#ifndef OCARINA_CORE_AUDIO_H
#define OCARINA_CORE_AUDIO_H

extern "C" {
#include <core/tags/track.h>
}
#include <gst/gst.h>
#include <string>
#include <stdint.h>


struct audio_ops {
	/* Called when a track is loaded. */
	void (*on_load)(struct track *, GstState);
};


/**
 * The audio driver class gives us an interface for using multiple
 * audio frameworks for audio playback.
 */
class AudioDriver {
protected:
	void (*on_error) (); /**< Error handling callback function.  */

public:
	AudioDriver();  /**< Default AudioDriver constructor. */
	virtual ~AudioDriver(); /**< AudioDriver destructor.          */


	/**
	 * Called to check if the audio library is currently playing a track.
	 *
	 * @return True if audio library is playing, false otherwise.
	 */
	virtual bool is_playing() = 0;


	/**
	 * Called to handle reaching the end-of-stream.
	 */
	void eos();
};


/**
 * Namespace for higher-level audio controls.
 */
namespace audio
{

	/**
	 * Stop playback and seek to the beginning of the track.
	 */
	void stop();

	void next(); /**< Find and load the next track that should be played. */
	void prev(); /**< Call the deck :: previous() function and load the result. */

	/**
	 * @return A pointer to the currently playing track object.
	 */
	struct track *current_track();

	/**
	 * Configure the automatic pausing feature.
	 *
	 * @param  enabled  Set to true to enable pausing, false to disable.
	 * @param  n  Number of tracks to play before pausing.
	 */
	void pause_after(bool, unsigned int);

	/**
	 * Call to find the current automatic pausing state.
	 *
	 * @return True if automatic pausing is enabled, false otherwise.
	 */
	bool pause_enabled();

	/**
	 * Call to find the number of tracks remaining before pausing.
	 *
	 * @return The number of tracks before pausing.
	 */
	unsigned int pause_count();

	/**
	 * Called to access an audio driver.
	 *
	 * @return The current driver used by the application.
	 */
	AudioDriver *get_driver();
};


/* Called to initialize the audio manager. */
void audio_init(int *, char ***, struct audio_ops *);

/* Called to deinitialize the audio manager. */
void audio_deinit();


/* Called to load a track for playback. */
bool audio_load(struct track *);

/* Called to begin playback. */
bool audio_play();

/* Called to pause playback. */
bool audio_pause();

/* Called to seek playback to a specific offset, in nanoseconds. */
bool audio_seek(gint64);

/* Called to find the current playback position, in nanoseconds. */
gint64 audio_position();

/* Called to find the duration of the current track. */
gint64 audio_duration();

GstElement *audio_get_player();
#endif /* OCARINA_CORE_AUDIO_H */