/* 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 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 AGI_SOUND_PCJR_H
#define AGI_SOUND_PCJR_H

#include "audio/audiostream.h"

namespace Agi {

#define CHAN_MAX 4

#define SAMPLE_RATE 22050

enum GenType {
	kGenSilence,
	kGenTone,
	kGenPeriod,
	kGenWhite
};

struct SndGenChan {
	const byte *data;
	uint16 duration;
	uint16 avail;   // turned on (1)  but when the channel's data runs out, it's set to (0)
	uint16 dissolveCount;
	byte attenuation;
	byte attenuationCopy;

	GenType genType;

	// for the sample mixer
	int freqCount;
};

struct ToneChan {
	int avail;

	int noteCount; // length of tone.. duration

	int freqCount;
	int freqCountPrev;
	int atten;  // volume

	GenType genType;
	int genTypePrev;

	int count;
	int scale;
	int sign;
	unsigned int noiseState; /* noise generator      */
	int feedback;            /* noise feedback mask */
};

class SoundGenPCJr : public SoundGen, public Audio::AudioStream {
public:
	SoundGenPCJr(AgiBase *vm, Audio::Mixer *pMixer);
	~SoundGenPCJr() override;

	void play(int resnum) override;
	void stop() override;

	// AudioStream API
	int readBuffer(int16 *buffer, const int numSamples) override;

	bool isStereo() const override {
		return false;
	}

	bool endOfData() const override {
		return false;
	}

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

private:
	int getNextNote(int ch);
	int getNextNote_v2(int ch);
	int getNextNote_v1(int ch);
	int volumeCalc(SndGenChan *chan);

	void writeData(uint8 val);

	int chanGen(int chan, int16 *stream, int len);

	int fillNoise(ToneChan *t, int16 *buf, int len);
	int fillSquare(ToneChan *t, int16 *buf, int len);

private:
	Common::Mutex _mutex;
	
	SndGenChan _channel[CHAN_MAX];
	ToneChan _tchannel[CHAN_MAX];
	int16 *_chanData;
	int _chanAllocated;

	int _dissolveMethod;
	int32 _periodicNoiseMask;

	uint8 *_v1data;
	uint32 _v1size;
	int _v1duration;

	int _reg;
};

} // End of namespace Agi

#endif /* AGI_SOUND_PCJR_H */