/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#ifndef SCI_SFX_SFX_ITERATOR_INTERNAL
#define SCI_SFX_SFX_ITERATOR_INTERNAL

#include "sci/sfx/iterator.h"
#include "sci/sfx/sci_midi.h"

#include "common/list.h"

namespace Sci {

/* States */

#define SI_STATE_UNINITIALISED -1
#define SI_STATE_DELTA_TIME 0 /* Now at a delta time */
#define SI_STATE_COMMAND 1 /* Now at a MIDI operation */
#define SI_STATE_PENDING 2 /* Pending for loop */
#define SI_STATE_FINISHED 3 /* End of song */
#define SI_STATE_PCM 4 /* Should report a PCM next (-> DELTA_TIME) */
#define SI_STATE_PCM_MAGIC_DELTA 5 /* Should report a ``magic'' one tick delta time next (goes on to FINISHED) */


/* Iterator types */

#define SCI_SONG_ITERATOR_TYPE_SCI0 0
#define SCI_SONG_ITERATOR_TYPE_SCI1 1

#define SIPFX __FILE__" : "


struct SongIteratorChannel {
	int state;	/* SI_STATE_* */
	int offset;     /* Offset into the data chunk */
	int end;	/* Last allowed byte in track */
	int id;		/* Some channel ID */
	int loop_offset;
	int delay;	/* Number of ticks before the
			** specified channel is next
			** used, or
			** CHANNEL_DELAY_MISSING to
			** indicate that the delay has
			** not yet been read  */

	/* Two additional offsets for recovering: */
	int initial_offset;
	int playmask; /* Active playmask (MIDI channels to play in here) */
	int notes_played; /* #of notes played since the last loop start */
	int loop_timepos; /* Total delay for this channel's loop marker */
	int total_timepos; /* Number of ticks since the beginning, ignoring loops */
	int timepos_increment; /* Number of ticks until the next command (to add) */

	int saw_notes;  /* Bitmask of channels we have currently played notes on */
	byte last_cmd;	/* Last operation executed, for running status */

public:
	void resetSynthChannels();
};

class BaseSongIterator : public SongIterator {
public:
	int polyphony[MIDI_CHANNELS]; /* # of simultaneous notes on each */
	int importance[MIDI_CHANNELS]; /* priority rating for each channel, 0 means unrated. */


	int ccc; /* Cumulative cue counter, for those who need it */
	byte resetflag; /* for 0x4C -- on DoSound StopSound, do we return to start? */
	int _deviceId; /* ID of the device we generating events for */
	int active_channels; /* Number of active channels */
	uint _size; /* Song size */
	byte *_data;

	int loops; /* Number of loops remaining */
	int recover_delay;

public:
	BaseSongIterator(byte *data, uint size, songit_id_t id);

	// Copy constructor taking care of memory handling
	BaseSongIterator(const BaseSongIterator&);

	~BaseSongIterator();
};

/********************************/
/*--------- SCI 0 --------------*/
/********************************/

class Sci0SongIterator : public BaseSongIterator {
public:
	SongIteratorChannel channel;

public:
	Sci0SongIterator(byte *data, uint size, songit_id_t id);

	int nextCommand(byte *buf, int *result);
	Audio::AudioStream *getAudioStream();
	SongIterator *handleMessage(Message msg);
	void init();
	int getTimepos();
	SongIterator *clone(int delta);
};


/********************************/
/*--------- SCI 1 --------------*/
/********************************/


struct Sci1Sample {
	/* Time left-- initially, this is 'Sample point 1'.
	 * After initialisation, it is 'sample point 1 minus the sample
	 * point of the previous sample'
	 */
	int delta;
	int size;
	bool announced; /* Announced for download (SI_PCM) */
	sfx_pcm_config_t format;
	byte *_data;
};

class Sci1SongIterator : public BaseSongIterator {
public:
	SongIteratorChannel _channels[MIDI_CHANNELS];

	/* Invariant: Whenever channels[i].delay == CHANNEL_DELAY_MISSING,
	** channel_offset[i] points to a delta time object. */

	bool _initialised; /* Whether the MIDI channel setup has been initialised */
	int _numChannels; /* Number of channels actually used */
	Common::List<Sci1Sample> _samples;
	int _numLoopedChannels; /* Number of channels that are ready to loop */

	int _delayRemaining; /* Number of ticks that haven't been polled yet */
	int _hold;

public:
	Sci1SongIterator(byte *data, uint size, songit_id_t id);
	~Sci1SongIterator();

	int nextCommand(byte *buf, int *result);
	Audio::AudioStream *getAudioStream();
	SongIterator *handleMessage(Message msg);
	void init();
	int getTimepos();
	SongIterator *clone(int delta);
};

#define PLAYMASK_NONE 0x0

/**********************************/
/*--------- Fast Forward ---------*/
/**********************************/

class FastForwardSongIterator : public SongIterator {
protected:
	SongIterator *_delegate;
	int _delta; /**< Remaining time */

public:
	FastForwardSongIterator(SongIterator *capsit, int delta);

	int nextCommand(byte *buf, int *result);
	Audio::AudioStream *getAudioStream();
	SongIterator *handleMessage(Message msg);
	int getTimepos();
	SongIterator *clone(int delta);
};


/**********************************/
/*--------- Tee iterator ---------*/
/**********************************/

enum {
	MAX_BUF_SIZE = 4,
	
	TEE_LEFT = 0,
	TEE_RIGHT = 1,
	TEE_LEFT_ACTIVE  = (1<<0),
	TEE_RIGHT_ACTIVE = (1<<1),
	TEE_LEFT_READY  = (1<<2), /**< left result is ready */
	TEE_RIGHT_READY = (1<<3), /**< right result is ready */
	TEE_LEFT_PCM = (1<<4),
	TEE_RIGHT_PCM = (1<<5),

	TEE_MORPH_NONE = 0, /**< Not waiting to self-morph */
	TEE_MORPH_READY = 1 /**< Ready to self-morph */
};

/**
 * This iterator combines two iterators, returns the next event available from either.
 */
class TeeSongIterator : public SongIterator {
public:
	int _status;

	int morph_deferred; /* One of TEE_MORPH_* above */

	struct {
		SongIterator *it;
		byte buf[MAX_BUF_SIZE];
		int result;
		int retval;

		byte channel_remap[MIDI_CHANNELS];
		/* Remapping for channels */

	} _children[2];

public:
	TeeSongIterator(SongIterator *left, SongIterator *right);
	~TeeSongIterator();

	int nextCommand(byte *buf, int *result);
	Audio::AudioStream *getAudioStream();
	SongIterator *handleMessage(Message msg);
	void init();
	int getTimepos() { return 0; }
	SongIterator *clone(int delta);
};

} // End of namespace Sci

#endif // SCI_SFX_SFX_ITERATOR_INTERNAL