/* Copyright (c) 2013-2016 Jeffrey Pfau
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef GB_AUDIO_H
#define GB_AUDIO_H

#include "util/common.h"

#include "third-party/blip_buf/blip_buf.h"

DECL_BITFIELD(GBAudioRegisterDuty, uint8_t);
DECL_BITS(GBAudioRegisterDuty, Length, 0, 6);
DECL_BITS(GBAudioRegisterDuty, Duty, 6, 2);

DECL_BITFIELD(GBAudioRegisterSweep, uint8_t);
DECL_BITS(GBAudioRegisterSweep, StepTime, 0, 3);
DECL_BIT(GBAudioRegisterSweep, Direction, 3);
DECL_BITS(GBAudioRegisterSweep, InitialVolume, 4, 4);

DECL_BITFIELD(GBAudioRegisterControl, uint16_t);
DECL_BITS(GBAudioRegisterControl, Rate, 0, 11);
DECL_BITS(GBAudioRegisterControl, Frequency, 0, 11);
DECL_BIT(GBAudioRegisterControl, Stop, 14);
DECL_BIT(GBAudioRegisterControl, Restart, 15);

DECL_BITFIELD(GBAudioRegisterSquareSweep, uint8_t);
DECL_BITS(GBAudioRegisterSquareSweep, Shift, 0, 3);
DECL_BIT(GBAudioRegisterSquareSweep, Direction, 3);
DECL_BITS(GBAudioRegisterSquareSweep, Time, 4, 3);

DECL_BITFIELD(GBAudioRegisterBank, uint8_t);
DECL_BIT(GBAudioRegisterBank, Size, 5);
DECL_BIT(GBAudioRegisterBank, Bank, 6);
DECL_BIT(GBAudioRegisterBank, Enable, 7);

DECL_BITFIELD(GBAudioRegisterBankVolume, uint8_t);
DECL_BITS(GBAudioRegisterBankVolume, VolumeGB, 5, 2);
DECL_BITS(GBAudioRegisterBankVolume, VolumeGBA, 5, 3);

DECL_BITFIELD(GBAudioRegisterNoiseFeedback, uint8_t);
DECL_BITS(GBAudioRegisterNoiseFeedback, Ratio, 0, 3);
DECL_BIT(GBAudioRegisterNoiseFeedback, Power, 3);
DECL_BITS(GBAudioRegisterNoiseFeedback, Frequency, 4, 4);

DECL_BITFIELD(GBAudioRegisterNoiseControl, uint8_t);
DECL_BIT(GBAudioRegisterNoiseControl, Stop, 6);
DECL_BIT(GBAudioRegisterNoiseControl, Restart, 7);

DECL_BITFIELD(GBRegisterNR50, uint8_t);
DECL_BITS(GBRegisterNR50, VolumeRight, 0, 3);
DECL_BITS(GBRegisterNR50, VolumeLeft, 4, 3);

DECL_BITFIELD(GBRegisterNR51, uint8_t);
DECL_BIT(GBRegisterNR51, Ch1Right, 0);
DECL_BIT(GBRegisterNR51, Ch2Right, 1);
DECL_BIT(GBRegisterNR51, Ch3Right, 2);
DECL_BIT(GBRegisterNR51, Ch4Right, 3);
DECL_BIT(GBRegisterNR51, Ch1Left, 4);
DECL_BIT(GBRegisterNR51, Ch2Left, 5);
DECL_BIT(GBRegisterNR51, Ch3Left, 6);
DECL_BIT(GBRegisterNR51, Ch4Left, 7);

DECL_BITFIELD(GBAudioEnable, uint8_t);
DECL_BIT(GBAudioEnable, PlayingCh1, 0);
DECL_BIT(GBAudioEnable, PlayingCh2, 1);
DECL_BIT(GBAudioEnable, PlayingCh3, 2);
DECL_BIT(GBAudioEnable, PlayingCh4, 3);
DECL_BIT(GBAudioEnable, Enable, 7);

struct GB;
struct GBAudioEnvelope {
	uint8_t length;
	uint8_t duty;
	uint8_t stepTime;
	uint8_t initialVolume;
	bool direction;
	int currentVolume;
	int dead;
	uint8_t nextStep;
};

struct GBAudioSquareControl {
	uint16_t frequency;
	uint8_t length;
	bool stop;
	int hi;
};

struct GBAudioChannel1 {
	uint8_t shift;
	uint8_t time;
	uint8_t sweepStep;
	bool direction;
	bool sweepEnable;
	bool sweepOccurred;
	uint16_t realFrequency;

	struct GBAudioEnvelope envelope;
	struct GBAudioSquareControl control;
	int8_t sample;
};

struct GBAudioChannel2 {
	struct GBAudioEnvelope envelope;
	struct GBAudioSquareControl control;
	int8_t sample;
};

struct GBAudioChannel3 {
	bool size;
	bool bank;
	bool enable;

	unsigned length;
	unsigned lengthShadow;
	uint8_t volume;

	uint16_t rate;
	bool stop;

	uint32_t wavedata[8];
	int8_t sample;
};

struct GBAudioChannel4 {
	struct GBAudioEnvelope envelope;

	uint8_t ratio;
	uint8_t frequency;
	bool power;
	bool stop;
	uint8_t length;

	uint32_t lfsr;
	int8_t sample;
};

struct GBAudio {
	struct GB* p;
	struct GBAudioChannel1 ch1;
	struct GBAudioChannel2 ch2;
	struct GBAudioChannel3 ch3;
	struct GBAudioChannel4 ch4;

	blip_t* left;
	blip_t* right;
	int16_t lastLeft;
	int16_t lastRight;
	int clock;
	int32_t clockRate;

	uint8_t volumeRight;
	uint8_t volumeLeft;
	bool ch1Right;
	bool ch2Right;
	bool ch3Right;
	bool ch4Right;
	bool ch1Left;
	bool ch2Left;
	bool ch3Left;
	bool ch4Left;

	bool playingCh1;
	bool playingCh2;
	bool playingCh3;
	bool playingCh4;

	int32_t nextEvent;
	int32_t eventDiff;
	int32_t nextFrame;
	int frame;
	int32_t nextSample;

	int32_t sampleInterval;

	int32_t nextCh1;
	int32_t nextCh2;
	int32_t nextCh3;
	int32_t nextCh4;
	bool enable;

	size_t samples;
	bool forceDisableCh[4];
	int masterVolume;
};

void GBAudioInit(struct GBAudio* audio, size_t samples);
void GBAudioDeinit(struct GBAudio* audio);
void GBAudioReset(struct GBAudio* audio);

void GBAudioResizeBuffer(struct GBAudio* audio, size_t samples);

void GBAudioWriteNR10(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR11(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR12(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR13(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR14(struct GBAudio* audio, uint8_t);

void GBAudioWriteNR21(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR22(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR23(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR24(struct GBAudio* audio, uint8_t);

void GBAudioWriteNR30(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR31(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR32(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR33(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR34(struct GBAudio* audio, uint8_t);

void GBAudioWriteNR41(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR42(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR43(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR44(struct GBAudio* audio, uint8_t);

void GBAudioWriteNR50(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR51(struct GBAudio* audio, uint8_t);
void GBAudioWriteNR52(struct GBAudio* audio, uint8_t);

int32_t GBAudioProcessEvents(struct GBAudio* audio, int32_t cycles);
void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right);

#endif