/* 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 AGI_SOUND_H
#define AGI_SOUND_H

#include "sound/audiostream.h"
#include "sound/mixer.h"

namespace Agi {

#define BUFFER_SIZE	410

#define SOUND_EMU_NONE	0
#define SOUND_EMU_PC	1
#define SOUND_EMU_TANDY	2
#define SOUND_EMU_MAC	3
#define SOUND_EMU_AMIGA	4
#define SOUND_EMU_APPLE2GS 5
#define SOUND_EMU_COCO3 6

#define WAVEFORM_SIZE   64
#define ENV_ATTACK	10000		/**< envelope attack rate */
#define ENV_DECAY       1000		/**< envelope decay rate */
#define ENV_SUSTAIN     100		/**< envelope sustain level */
#define ENV_RELEASE	7500		/**< envelope release rate */
#define NUM_CHANNELS    7		/**< number of sound channels */

/**
 * AGI sound note structure.
 */
struct AgiNote {
	uint16 duration;    ///< Note duration
	uint16 freqDiv;     ///< Note frequency divisor (10-bit)
	uint8  attenuation; ///< Note volume attenuation (4-bit)

	/** Reads an AgiNote through the given pointer. */
	void read(const uint8 *ptr) {
		duration = READ_LE_UINT16(ptr);
		uint16 freqByte0 = *(ptr + 2); // Bits 4-9 of the frequency divisor
		uint16 freqByte1 = *(ptr + 3); // Bits 0-3 of the frequency divisor
		// Merge the frequency divisor's bits together into a single variable
		freqDiv = ((freqByte0 & 0x3F) << 4) | (freqByte1 & 0x0F);
		attenuation = *(ptr + 4) & 0x0F;
	}
};

struct CoCoNote {
	uint8  freq;
	uint8  volume;
	uint16 duration;    ///< Note duration

	/** Reads a CoCoNote through the given pointer. */
	void read(const uint8 *ptr) {
		freq = *ptr;
		volume = *(ptr + 1);
		duration = READ_LE_UINT16(ptr + 2);
	}
};

/**
 * AGI sound resource types.
 * It's probably coincidence that all the values here are powers of two
 * as they're simply the different used values in AGI sound resources'
 * starts (The first 16-bit little endian word, to be precise).
 */
enum AgiSoundType {
	AGI_SOUND_SAMPLE	= 0x0001,
	AGI_SOUND_MIDI		= 0x0002,
	AGI_SOUND_4CHN		= 0x0008
};
enum AgiSoundFlags {
	AGI_SOUND_LOOP		= 0x0001,
	AGI_SOUND_ENVELOPE	= 0x0002
};
enum AgiSoundEnv {
	AGI_SOUND_ENV_ATTACK	= 3,
	AGI_SOUND_ENV_DECAY		= 2,
	AGI_SOUND_ENV_SUSTAIN	= 1,
	AGI_SOUND_ENV_RELEASE	= 0
};


/**
 * AGI engine sound channel structure.
 */
struct ChannelInfo {
	AgiSoundType type;
	const uint8 *ptr; // Pointer to the AgiNote data
	const int16 *ins;
	int32 size;
	uint32 phase;
	uint32 flags;	// ORs values from AgiSoundFlags
	AgiSoundEnv adsr;
	int32 timer;
	uint32 end;
	uint32 freq;
	uint32 vol;
	uint32 env;
};

class SoundMgr;

/**
 * AGI sound resource structure.
 */
class AgiSound {
public:
	AgiSound(SoundMgr &manager) : _manager(manager), _isPlaying(false), _isValid(false) {}
	virtual ~AgiSound() {}
	virtual void play()      { _isPlaying = true; }
	virtual void stop()      { _isPlaying = false; }
	virtual bool isPlaying() { return _isPlaying; }
	virtual uint16 type() = 0;

	/**
	 * A named constructor for creating different types of AgiSound objects
	 * from a raw sound resource.
	 *
	 * NOTE: This function should take responsibility for freeing the raw resource
	 * from memory using free() or delegate the responsibility onwards to some other
	 * function!
	 */
	static AgiSound *createFromRawResource(uint8 *data, uint32 len, int resnum, SoundMgr &manager);

protected:
	SoundMgr &_manager; ///< AGI sound manager object
	bool _isPlaying;    ///< Is the sound playing?
	bool _isValid;      ///< Is this a valid sound object?
};

class PCjrSound : public AgiSound {
public:
	PCjrSound(uint8 *data, uint32 len, int resnum, SoundMgr &manager);
	~PCjrSound() { if (_data != NULL) free(_data); }
	virtual uint16 type() { return _type; }
	const uint8 *getVoicePointer(uint voiceNum);
protected:
	uint8 *_data; ///< Raw sound resource data
	uint32 _len;  ///< Length of the raw sound resource
	uint16 _type; ///< Sound resource type
};

class AgiEngine;
class AgiBase;
class IIgsSoundMgr;

struct IIgsExeInfo;

class SoundMgr : public Audio::AudioStream {
	AgiBase *_vm;

public:
	SoundMgr(AgiBase *agi, Audio::Mixer *pMixer);
	~SoundMgr();
	virtual void setVolume(uint8 volume);

	// AudioStream API
	int readBuffer(int16 *buffer, const int numSamples) {
		premixerCall(buffer, numSamples / 2);
		return numSamples;
	}

	bool isStereo() const {
		return false;
	}

	bool endOfData() const {
		return false;
	}

	int getRate() const {
		// FIXME: Ideally, we should use _sampleRate.
		return 22050;
	}

private:
	Audio::Mixer *_mixer;
	Audio::SoundHandle _soundHandle;
	uint32 _sampleRate;

	bool _playing;
	ChannelInfo _chn[NUM_CHANNELS];
	IIgsSoundMgr *_gsSound;
	int _endflag;
	int _playingSound;
	uint8 _env;
	bool _disabledMidi;

	int16 *_sndBuffer;
	const int16 *_waveform;

	bool _useChorus;

	void premixerCall(int16 *buf, uint len);
	void fillAudio(void *udata, int16 *stream, uint len);

public:
	void unloadSound(int);
	void playSound();
	int initSound();
	void deinitSound();
	void startSound(int, int);
	void stopSound();
	void stopNote(int i);
	void playNote(int i, int freq, int vol);
	void playAgiSound();
	void playCoCoSound();
	uint32 mixSound();
	bool loadInstruments();
	void playMidiSound();
	void playSampleSound();
	const IIgsExeInfo *getIIgsExeInfo(enum AgiGameID gameid) const;
	static bool convertWave(Common::SeekableReadStream &source, int8 *dest, uint length);
};

} // End of namespace Agi

#endif /* AGI_SOUND_H */