// Copyright (c) 2012- PPSSPP Project.

// 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, version 2.0 or later versions.

// 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 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.

// SAS is a software mixing engine that runs on the Media Engine CPU. We just HLE it.
// This is a very rough implementation that needs lots of work.
//
// JPCSP is, as it often is, a pretty good reference although I didn't actually use it much yet:
// http://code.google.com/p/jpcsp/source/browse/trunk/src/jpcsp/HLE/modules150/sceSasCore.java

#include "base/basictypes.h"

#include "HLE.h"
#include "../MIPS/MIPS.h"

#include "sceSas.h"
#include "sceKernel.h"

static const double f[5][2] = 
{ { 0.0, 0.0 },
{	 60.0 / 64.0,	0.0 },
{	115.0 / 64.0, -52.0 / 64.0 },
{	 98.0 / 64.0, -55.0 / 64.0 },
{	122.0 / 64.0, -60.0 / 64.0 } };

// VAG is a Sony ADPCM audio compression format, which goes all the way back to the PSX.
// It compresses 28 16-bit samples into a block of 16 bytes.
// TODO: Get rid of the doubles, making sure it does not impact sound quality.
// Doubles are pretty fast on Android devices these days though.
class VagDecoder
{
public:
	void Start(u8 *data)
	{
		data_ = data;
		curSample = 28;
		s_1 = 0.0;	// per block?
		s_2 = 0.0;
	}

	int GetSample()
	{
		if (end_)
			return 0;
		if (curSample == 28)
			Decode();
		if (end_)
			return 0;
		return samples[curSample++];
	}

	bool Decode();
	bool End() const { return end_; }

	u8 GetByte() {
		return *data_++;
	}

private:
	double samples[28];
	int curSample;

	u8 *data_;

	// rolling state. start at 0, should probably reset to 0 on loops?
	double s_1;
	double s_2;

	bool end_;
};

bool VagDecoder::Decode()
{
	int predict_nr = GetByte();
	int shift_factor = predict_nr & 0xf;
	predict_nr >>= 4;
	int flags = GetByte();
	if (flags == 7)
	{
		end_ = true;
		return false;
	}
	for (int i = 0; i < 28; i += 2) 
	{
		int d = GetByte();
		int s = (d & 0xf) << 12;
		if (s & 0x8000)
			s |= 0xffff0000;
		samples[i] = (double)(s >> shift_factor);
		s = (d & 0xf0) << 8;
		if (s & 0x8000)
			s |= 0xffff0000;
		samples[i + 1] = (double)(s >> shift_factor);
	}
	for (int i = 0; i < 28; i++)
	{
		samples[i] = samples[i] + s_1 * f[predict_nr][0] + s_2 * f[predict_nr][1];
		s_2 = s_1;
		s_1 = samples[i];
	}
	curSample = 0;
	return true;
}

// A SAS voice.
// TODO: Look into pre-decoding the VAG samples on SetVoice instead of decoding them on the fly.
// It's not very likely that games encode VAG dynamically.
struct Voice
{
	u32 vagAddr;
	int samplePos;
	int size;
	int loop;
	int volumeLeft;
	int volumeRight;
	int volumeLeftSend;	// volume to "Send" (audio-lingo) to the effects processing engine, like reverb
	int volumeRightSend;
	int pitch;
	bool endFlag;
	bool playing;

	VagDecoder vag;
};

class SasInstance
{
public:
	enum { NUM_VOICES = 32 };
	Voice voices[NUM_VOICES];
	int grainSize;
	int maxVoices;
	int sampleRate;

	void mix(u32 outAddr);
};

// TODO - allow more than one, associating each with one Core pointer (passed in to all the functions)
// No known games use more than one instance of Sas though.
SasInstance sas;	

// TODO: Make deterministic, by adding staging buffers that we pump out on a fixed CoreTiming-scheduled interval.

void SasInstance::mix(u32 outAddr)
{
	s16 *out = (s16 *)Memory::GetPointer(outAddr);
	// Don't need to memset, done by the caller.
	for (int v = 0; v < NUM_VOICES; v++)	 // sas.maxVoices?
	{
		Voice &voice = sas.voices[v];

		if (voice.playing && voice.vagAddr != 0)
		{
			for (int i = 0; i < grainSize; i++)
			{
				int sample = voice.vag.GetSample();
				voice.samplePos++;
				if (voice.samplePos >= voice.size || voice.vag.End())
				{
					voice.playing = false;
					break;
				}
				int l = sample; int r = sample; //* (voice.volumeLeft >> 16), r = sample * (voice.volumeRight >> 16);

				// TODO: should mix into a temporary 32-bit buffer and then clip down
				out[i * 2] += l;
				out[i * 2 + 1] += r;
			}
		}
	}
}

u32 sceSasInit(u32 core, u32 grainSize, u32 maxVoices, u32 unknown, u32 sampleRate)
{
	DEBUG_LOG(HLE,"0=sceSasInit()");
	memset(&sas, 0, sizeof(sas));
	sas.grainSize = grainSize;
	sas.maxVoices = maxVoices;
	sas.sampleRate = sampleRate;
	for (int i = 0; i < 32; i++) {
		sas.voices[i].playing = false;
	}
	return 0;
}

u32 sceSasGetEndFlag()
{
	u32 endFlag = 0;
	for (int i = 0; i < sas.maxVoices; i++) {
		if (!sas.voices[i].playing)
			endFlag |= 1 << i;
	}
	DEBUG_LOG(HLE,"%08x=sceSasGetEndFlag()", endFlag);
	return endFlag;
}

// Runs the mixer
void _sceSasCore()
{
	u32 outAddr = PARAM(1);
	DEBUG_LOG(HLE,"0=sceSasCore(, %08x)	(grain: %i samples)", outAddr, sas.grainSize);
	memset(Memory::GetPointer(outAddr), 0, sas.grainSize * 2 * 2);
	sas.mix(outAddr);
	RETURN(0);
}

// Another way of running the mixer, what was the difference again?
void _sceSasCoreWithMix()
{
	u32 outAddr = PARAM(1);
	DEBUG_LOG(HLE,"0=sceSasCoreWithMix(, %08x)", outAddr);
	sas.mix(outAddr);
	RETURN(0);
}

void sceSasSetVoice()
{
	u32 core = PARAM(0);
	int voiceNum = PARAM(1);
	u32 vagAddr = PARAM(2);
	int size = PARAM(3);
	int loop = PARAM(4);
	DEBUG_LOG(HLE,"0=sceSasSetVoice(core=%08x, voicenum=%i, vag=%08x, size=%i, loop=%i)", 
		core, voiceNum, vagAddr, size, loop);

	//Real VAG header is 0x30 bytes behind the vagAddr
	Voice &v = sas.voices[voiceNum];
	v.vagAddr = vagAddr;
	v.size = size;
	v.loop = loop;
	v.playing = false;
	RETURN(0);
}

void sceSasSetVolume()
{
	u32 core = PARAM(0);
	int voiceNum = PARAM(1);
	int l = PARAM(2);
	int r = PARAM(3);
	int el = PARAM(4);
	int er = PARAM(5);
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasSetVolume(core=%08x, voicenum=%i, l=%i, r=%i, el=%i, er=%i", core, voiceNum, l, r, el, er);
	Voice &v = sas.voices[voiceNum];
	v.volumeLeft = l;
	v.volumeRight = r;
	RETURN(0);
}

void sceSasSetPitch()
{
	u32 core = PARAM(0);
	int voiceNum = PARAM(1);
	int pitch = PARAM(2);
	Voice &v = sas.voices[voiceNum];
	v.pitch = pitch;
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasSetPitch(core=%08x, voicenum=%i, pitch=%i)", core, voiceNum, pitch);
	RETURN(0);
}

void sceSasSetKeyOn()
{
	u32 core = PARAM(0);
	int voiceNum = PARAM(1);
	DEBUG_LOG(HLE,"0=sceSasSetKeyOff(core=%08x, voicenum=%i)", core, voiceNum);
	Voice &v = sas.voices[voiceNum];
	v.vag.Start(Memory::GetPointer(v.vagAddr));
	v.playing = true;
	RETURN(0);
}

// TODO: We really need ADSR work: 
// sceSasSetKeyOff can be used to start sounds, that just sound during the Release phase!
void sceSasSetKeyOff()
{
	u32 core = PARAM(0);
	int voiceNum = PARAM(1);
	DEBUG_LOG(HLE,"0=sceSasSetKeyOff(core=%08x, voicenum=%i)", core, voiceNum);
	Voice &v = sas.voices[voiceNum];
	v.playing = false;	// not right! Should directly enter Release envelope stage instead!
	RETURN(0);
}

void sceSasSetADSR()
{
	u32 core = PARAM(0);
	int voiceNum = PARAM(1);
	int flag = PARAM(2);
	int a = PARAM(3);
	int d = PARAM(4);
	int s = PARAM(5);
	int r = PARAM(6); //??
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasSetADSR(core=%08x, voicenum=%i, flag=%i, a=%08x, d=%08x, s=%08x, r=%08x)", 
		core, voiceNum, flag, a,d,s,r);
	RETURN(0);
}

void sceSasSetADSRMode()
{
	u32 core = PARAM(0);
	int voiceNum = PARAM(1);
	int flag = PARAM(2);
	int a = PARAM(3);
	int d = PARAM(4);
	int s = PARAM(5);
	int r = PARAM(6); //??
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasSetADSRMode(core=%08x, voicenum=%i, flag=%i, a=%08x, d=%08x, s=%08x, r=%08x)", 
		core, voiceNum, flag, a,d,s,r);
	RETURN(0);
}

// http://code.google.com/p/jpcsp/source/browse/trunk/src/jpcsp/HLE/modules150/sceSasCore.java

u32 sceSasSetSimpleADSR(u32 core, u32 voiceNum, u32 ADSREnv1, u32 ADSREnv2)
{
	DEBUG_LOG(HLE,"UNIMPL 0=sasSetSimpleADSR(%08x, %i, %08x, %08x)", core, voiceNum, ADSREnv1, ADSREnv2);
	ADSREnv1 &= 0xFFFF;
	ADSREnv2 &= 0xFFFF;
	//....
	return 0;
}

u32 sceSasGetEnvelopeHeight(u32 core, u32 voiceNum)
{
	// Spam reduction
	if (voiceNum == 17)
	{
		DEBUG_LOG(HLE,"UNIMPL 0=sceSasGetEnvelopeHeight(core=%08x, voicenum=%i)", core, voiceNum);
	}
	Voice &v = sas.voices[voiceNum];

	return v.playing ? 0x3fffffff : 0;
}

void sceSasRevType()
{
	u32 core = PARAM(0);
	int type = PARAM(1);
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasRevType(core=%08x, type=%i)", core, type);
	RETURN(0);
}

void sceSasRevParam()
{
	u32 core = PARAM(0);
	int param1 = PARAM(1);
	int param2 = PARAM(2);
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasRevParam(core=%08x, param1=%i, param2=%i)", core, param1, param2);
	RETURN(0);
}

void sceSasRevEVOL()
{
	u32 core = PARAM(0);
	int param1 = PARAM(1);
	int param2 = PARAM(2);
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasRevEVOL(core=%08x, param1=%i, param2=%i)", core, param1, param2);
	RETURN(0);
}

void sceSasRevVON()
{
	u32 core = PARAM(0);
	int param1 = PARAM(1);
	int param2 = PARAM(2);
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasRevEVOL(core=%08x, param1=%i, param2=%i)", core, param1, param2);
	RETURN(0);
}

void sceSasGetOutputMode()
{
	u32 core = PARAM(0);
	int param1 = PARAM(1);
	int param2 = PARAM(2);
	DEBUG_LOG(HLE,"UNIMPL 0=sceSasGetOutputMode(core=%08x, param1=%i, param2=%i)", core, param1, param2);
	RETURN(0);
}


const HLEFunction sceSasCore[] =
{
	{0x42778a9f, WrapU_UUUUU<sceSasInit>, "__sceSasInit"}, // (SceUID * sasCore, int grain, int maxVoices, int outputMode, int sampleRate)
	{0xa3589d81, _sceSasCore, "__sceSasCore"},
	{0x50a14dfc, _sceSasCoreWithMix, "__sceSasCoreWithMix"},	// Process and mix into buffer (int sasCore, int sasInOut, int leftVolume, int rightVolume)
	{0x68a46b95, WrapU_V<sceSasGetEndFlag>, "__sceSasGetEndFlag"},	// int sasCore
	{0x440ca7d8, sceSasSetVolume, "__sceSasSetVolume"},
	{0xad84d37f, sceSasSetPitch, "__sceSasSetPitch"},
	{0x99944089, sceSasSetVoice, "__sceSasSetVoice"},	// (int sasCore, int voice, int vagAddr, int size, int loopmode)
	{0xb7660a23, 0, "__sceSasSetNoise"},
	{0x019b25eb, sceSasSetADSR, "__sceSasSetADSR"},
	{0x9ec3676a, sceSasSetADSRMode, "__sceSasSetADSRmode"},
	{0x5f9529f6, 0, "__sceSasSetSL"},
	{0x74ae582a, WrapU_UU<sceSasGetEnvelopeHeight>, "__sceSasGetEnvelopeHeight"},	
	{0xcbcd4f79, WrapU_UUUU<sceSasSetSimpleADSR>, "__sceSasSetSimpleADSR"},
	{0xa0cf2fa4, sceSasSetKeyOff, "__sceSasSetKeyOff"},
	{0x76f01aca, sceSasSetKeyOn, "__sceSasSetKeyOn"},	// (int sasCore, int voice)
	{0xf983b186, sceSasRevVON, "__sceSasRevVON"},	// int sasCore, int dry, int wet
	{0xd5a229c9, sceSasRevEVOL, "__sceSasRevEVOL"},	// (int sasCore, int leftVol, int rightVol)	// effect volume
	{0x33d4ab37, sceSasRevType, "__sceSasRevType"},	 // (int sasCore, int type)
	{0x267a6dd2, sceSasRevParam, "__sceSasRevParam"},	// (int sasCore, int delay, int feedback)
	{0x2c8e6ab3, 0, "__sceSasGetPauseFlag"}, // int sasCore
	{0x787d04d5, 0, "__sceSasSetPause"},
	{0xa232cbe6, 0, "__sceSasSetTriangularWave"},		// (int sasCore, int voice, int unknown)
	{0xd5ebbbcd, 0, "__sceSasSetSteepWave"},	 // (int sasCore, int voice, int unknown)		// square wave?
	{0xBD11B7C2, 0, "__sceSasGetGrain"},
	{0xd1e0a01e, 0, "__sceSasSetGrain"},
	{0xe175ef66, sceSasGetOutputMode, "__sceSasGetOutputmode"},
	{0xe855bf76, 0, "__sceSasSetOutputmode"},
	{0x07f58c24, 0, "__sceSasGetAllEnvelopeHeights"},	// (int sasCore, int heightAddr)	32-bit heights, 0-0x40000000
	{0xE1CD9561, 0, "__sceSasSetVoicePCM"},
};

void Register_sceSasCore()
{
	RegisterModule("sceSasCore", ARRAY_SIZE(sceSasCore), sceSasCore);
}