/* SPU2-X, A plugin for Emulating the Sound Processing Unit of the Playstation 2
 * Developed and maintained by the Pcsx2 Development Team.
 * 
 * Original portions from SPU2ghz are (c) 2008 by David Quintana [gigaherz]
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free 
 * Software Foundation; either version 2.1 of the the License, or (at your
 * option) any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT 
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License along
 * with this library; if not, write to the Free Software Foundation, Inc., 59
 * Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 */

#include "spu2.h"


StereoOut32 StereoOut32::Empty( 0, 0 );

StereoOut32::StereoOut32( const StereoOut16& src ) :
	Left( src.Left ),
	Right( src.Right )
{
}

StereoOut32::StereoOut32( const StereoOutFloat& src ) :
	Left( (s32)(src.Left * 2147483647.0f) ),
	Right( (s32)(src.Right * 2147483647.0f) )
{
}

StereoOut16 StereoOut32::DownSample() const
{
	return StereoOut16(
		Left >> SndOutVolumeShift,
		Right >> SndOutVolumeShift
	);
}

StereoOut32 StereoOut16::UpSample() const
{
	return StereoOut32(
		Left << SndOutVolumeShift,
		Right << SndOutVolumeShift
	);

}


class NullOutModule: public SndOutModule
{
public:
	s32  Init()  { return 0; }
	void Close() { }
	s32  Test() const { return 0; }
	void Configure(HWND parent)  { }
	bool Is51Out() const { return false; }
	int GetEmptySampleCount() const { return 0; }
	
	const wchar_t* GetIdent() const
	{
		return _T("nullout");
	}

	const wchar_t* GetLongName() const
	{
		return _T("No Sound (Emulate SPU2 only)");
	}

} NullOut;

SndOutModule* mods[]=
{
	&NullOut,
	XAudio2Out,
	DSoundOut,
	WaveOut,
	NULL		// signals the end of our list
};

int FindOutputModuleById( const wchar_t* omodid )
{
	int modcnt = 0;
	while( mods[modcnt] != NULL )
	{
		if( wcscmp( mods[modcnt]->GetIdent(), omodid ) == 0 )
			break;
		++modcnt;
	}
	return modcnt;
}

StereoOut32 *SndBuffer::m_buffer;
s32 SndBuffer::m_size;
s32 SndBuffer::m_rpos;
s32 SndBuffer::m_wpos;
s32 SndBuffer::m_data;

bool SndBuffer::m_underrun_freeze;
StereoOut32* SndBuffer::sndTempBuffer = NULL;
StereoOut16* SndBuffer::sndTempBuffer16 = NULL;
int SndBuffer::sndTempProgress = 0;

int GetAlignedBufferSize( int comp )
{
	return (comp + SndOutPacketSize-1) & ~(SndOutPacketSize-1);
}

// Returns TRUE if there is data to be output, or false if no data
// is available to be copied.
bool SndBuffer::CheckUnderrunStatus( int& nSamples, int& quietSampleCount )
{
	quietSampleCount = 0;
	if( m_underrun_freeze )
	{			
		int toFill = (int)(m_size * ( timeStretchDisabled ? 0.50f : 0.1f ) );
		toFill = GetAlignedBufferSize( toFill );

		// toFill is now aligned to a SndOutPacket

		if( m_data < toFill )
		{
			quietSampleCount = nSamples;
			return false;
		}

		m_underrun_freeze = false;
		if( MsgOverruns() )
			ConLog(" * SPU2 > Underrun compensation (%d packets buffered)\n", toFill / SndOutPacketSize );
		lastPct = 0.0;		// normalize timestretcher
	}
	else if( m_data < nSamples )
	{
		nSamples = m_data;
		quietSampleCount = SndOutPacketSize - m_data;
		m_underrun_freeze = true;

		if( !timeStretchDisabled )
			timeStretchUnderrun();

		return nSamples != 0;
	}

	return true;
}

void SndBuffer::_InitFail()
{
	// If a failure occurs, just initialize the NoSound driver.  This'll allow
	// the game to emulate properly (hopefully), albeit without sound.
	OutputModule = FindOutputModuleById( NullOut.GetIdent() );
	mods[OutputModule]->Init();
}

void SndBuffer::_WriteSamples(StereoOut32 *bData, int nSamples)
{
	int free = m_size-m_data;
	m_predictData = 0;

	jASSUME( m_data <= m_size );

	// Problem:
	//  If the SPU2 gets out of sync with the SndOut device, the writepos of the
	//  circular buffer will overtake the readpos, leading to a prolonged period
	//  of hopscotching read/write accesses (ie, lots of staticy crap sound for
	//  several seconds).
	//
	// Compromise:
	//  When an overrun occurs, we adapt by discarding a portion of the buffer.
	//  The older portion of the buffer is discarded rather than incoming data,
	//  so that the overall audio synchronization is better.

	if( free < nSamples )
	{
		// Buffer overrun!
		// Dump samples from the read portion of the buffer instead of dropping
		// the newly written stuff.

		s32 comp;

		if( !timeStretchDisabled )
		{
			comp = timeStretchOverrun();
		}
		else
		{
			// Toss half the buffer plus whatever's being written anew:
			comp = GetAlignedBufferSize( (m_size + nSamples ) / 2 );
			if( comp > (m_size-SndOutPacketSize) ) comp = m_size-SndOutPacketSize;
		}

		m_data -= comp;
		m_rpos = (m_rpos+comp) % m_size;
		if( MsgOverruns() )
			ConLog(" * SPU2 > Overrun Compensation (%d packets tossed)\n", comp / SndOutPacketSize );
		lastPct = 0.0;		// normalize the timestretcher
	}

	// copy in two phases, since there's a chance the packet
	// wraps around the buffer (it'd be nice to deal in packets only, but
	// the timestretcher and DSP options require flexibility).

	const int endPos = m_wpos + nSamples;
	const int secondCopyLen = endPos - m_size;
	StereoOut32* wposbuffer = &m_buffer[m_wpos];

	m_data += nSamples;
	if( secondCopyLen > 0 )
	{
		nSamples -= secondCopyLen;
		memcpy( m_buffer, &bData[nSamples], secondCopyLen * sizeof( *bData ) );
		m_wpos = secondCopyLen;
	}
	else
		m_wpos += nSamples;

	memcpy( wposbuffer, bData, nSamples * sizeof( *bData ) );
}

void SndBuffer::Init()
{
	if( mods[OutputModule] == NULL )
	{
		_InitFail();
		return;
	}

	// initialize sound buffer
	// Buffer actually attempts to run ~50%, so allocate near double what
	// the requested latency is:


	m_rpos = 0;
	m_wpos = 0;
	m_data = 0;

	try
	{
		const float latencyMS = SndOutLatencyMS * (timeStretchDisabled ? 1.5f : 2.0f );
		m_size = GetAlignedBufferSize( (int)(latencyMS * SampleRate / 1000.0f ) );
		m_buffer = new StereoOut32[m_size];
		m_underrun_freeze = false;

		sndTempBuffer = new StereoOut32[SndOutPacketSize];
		sndTempBuffer16 = new StereoOut16[SndOutPacketSize];
	}
	catch( std::bad_alloc& )
	{
		// out of memory exception (most likely)

		SysMessage( "Out of memory error occurred while initializing SPU2." );
		_InitFail();
		return;
	}

	// clear buffers!
	// Fixes loopy sounds on emu resets.
	memset( sndTempBuffer, 0, sizeof(StereoOut32) * SndOutPacketSize );
	memset( sndTempBuffer16, 0, sizeof(StereoOut16) * SndOutPacketSize );

	sndTempProgress = 0;

	soundtouchInit();		// initializes the timestretching

	// some crap
	spdif_set51(mods[OutputModule]->Is51Out());

	// initialize module
	if( mods[OutputModule]->Init() == -1 ) _InitFail();
}

void SndBuffer::Cleanup()
{
	mods[OutputModule]->Close();

	SAFE_DELETE_ARRAY( m_buffer );
	SAFE_DELETE_ARRAY( sndTempBuffer );
	SAFE_DELETE_ARRAY( sndTempBuffer16 );
}

int SndBuffer::m_dsp_progress = 0;
int SndBuffer::m_dsp_writepos = 0;

int SndBuffer::m_timestretch_progress = 0;

void SndBuffer::Write( const StereoOut32& Sample )
{
	// Log final output to wavefile.
	WaveDump::WriteCore( 1, CoreSrc_External, Sample.DownSample() );

	RecordWrite( Sample.DownSample() );

	if(mods[OutputModule] == &NullOut) // null output doesn't need buffering or stretching! :p
		return;

	sndTempBuffer[sndTempProgress++] = Sample;

	// If we haven't accumulated a full packet yet, do nothing more:
	if(sndTempProgress < SndOutPacketSize) return;
	sndTempProgress = 0;

	if( dspPluginEnabled )
	{
		// Convert in, send to winamp DSP, and convert out.

		for( int i=0; i<SndOutPacketSize; ++i, ++m_dsp_writepos ) { sndTempBuffer16[m_dsp_writepos] = sndTempBuffer[i].DownSample(); }
		m_dsp_progress += DspProcess( (s16*)sndTempBuffer16, SndOutPacketSize );

		// Some ugly code to ensure full packet handling:
		int ei = 0;
		while( m_dsp_progress >= SndOutPacketSize )
		{
			for( int i=0; i<SndOutPacketSize; ++i, ++ei ) { sndTempBuffer[i] = sndTempBuffer16[ei].UpSample(); }

			if( !timeStretchDisabled )
				timeStretchWrite();
			else
				_WriteSamples(sndTempBuffer, sndTempProgress);

			m_dsp_progress -= SndOutPacketSize;
		}
		
		// copy any leftovers to the front of the dsp buffer.
		if( m_dsp_progress > 0 )
		{
			memcpy( &sndTempBuffer16[ei], sndTempBuffer16,
				sizeof(sndTempBuffer16[0]) * m_dsp_progress
			);
		}
	}
	else
	{
		if( !timeStretchDisabled )
			timeStretchWrite();
		else
			_WriteSamples(sndTempBuffer, SndOutPacketSize);
	}
}

s32 SndBuffer::Test()
{
	if( mods[OutputModule] == NULL )
		return -1;

	return mods[OutputModule]->Test();
}

void SndBuffer::Configure(HWND parent, u32 module )
{
	if( mods[module] == NULL )
		return;

	mods[module]->Configure(parent);
}

