#include "global.h"
#include "RageSoundDriver_WaveOut.h"

#pragma comment(lib, "winmm.lib")

#include "RageTimer.h"
#include "RageLog.h"
#include "RageSound.h"
#include "RageUtil.h"
#include "RageSoundManager.h"

#include "SDL.h"

const int channels = 2;
const int bytes_per_frame = channels*2;		/* 16-bit */
const int samplerate = 44100;
const int buffersize_frames = 1024*8;	/* in frames */
const int buffersize = buffersize_frames * bytes_per_frame; /* in bytes */

const int num_chunks = 8;
const int chunksize_frames = buffersize_frames / num_chunks;
const int chunksize = buffersize / num_chunks;

static CString wo_ssprintf( MMRESULT err, const char *fmt, ...)
{
	char buf[MAXERRORLENGTH];
	waveOutGetErrorText(err, buf, MAXERRORLENGTH);

    va_list	va;
    va_start(va, fmt);
    CString s = vssprintf( fmt, va );
    va_end(va);

	return s += ssprintf( "(%s)", buf );
}

int RageSound_WaveOut::MixerThread_start(void *p)
{
	((RageSound_WaveOut *) p)->MixerThread();
	return 0;
}

void RageSound_WaveOut::MixerThread()
{
	/* SOUNDMAN will be set once RageSoundManager's ctor returns and
	 * assigns it; we might get here before that happens, though. */
	while(!SOUNDMAN && !shutdown) Sleep(10);

	if(!SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_ABOVE_NORMAL))
		LOG->Warn(werr_ssprintf(GetLastError(), "Failed to set sound thread priority"));

	while(!shutdown) {
		while(GetData())
			;

		WaitForSingleObject(sound_event, 10);
	}

	waveOutReset(wo);
}

bool RageSound_WaveOut::GetData()
{
	LockMutex L(SOUNDMAN->lock);

	/* Look for a free buffer. */
	int b;
	for(b = 0; b < num_chunks; ++b)
		if(buffers[b].dwFlags & WHDR_DONE) break;

	if(b == num_chunks) return false;

	/* Create a 32-bit buffer to mix sounds. */
	static Sint16 *buf = NULL;
	int bufsize = chunksize_frames * channels;
	if(!buf)
		buf = new Sint16[bufsize];
	memset(buf, 0, bufsize*sizeof(Uint16));
	memset(buffers[b].lpData, 0, bufsize*sizeof(Uint16));
	static SoundMixBuffer mix;

	const int64_t play_pos = last_cursor_pos;
    const int64_t cur_play_pos = GetPosition( NULL );

	for(unsigned i = 0; i < sounds.size(); ++i)
	{
		if(sounds[i]->stopping)
			continue;

        int bytes_read = 0;
        int bytes_left = chunksize;

		if( !sounds[i]->start_time.IsZero() )
		{
			/* If the sound is supposed to start at a time past this buffer, insert silence. */
			const int64_t iFramesUntilThisBuffer = play_pos - cur_play_pos;
			const float fSecondsBeforeStart = -sounds[i]->start_time.Ago();
			const int64_t iFramesBeforeStart = int64_t(fSecondsBeforeStart * samplerate);
			const int64_t iSilentFramesInThisBuffer = iFramesBeforeStart-iFramesUntilThisBuffer;
			const int iSilentBytesInThisBuffer = clamp( int(iSilentFramesInThisBuffer * bytes_per_frame), 0, bytes_left );

			memset( buf+bytes_read, 0, iSilentBytesInThisBuffer );
			bytes_read += iSilentBytesInThisBuffer;
			bytes_left -= iSilentBytesInThisBuffer;

			if( !iSilentBytesInThisBuffer )
				sounds[i]->start_time.SetZero();
		}

		/* Call the callback. */
		int got = sounds[i]->snd->GetPCM( (char *) buf+bytes_read, bytes_left, play_pos+bytes_read/bytes_per_frame );
        bytes_read += got;
        bytes_left -= got;

		mix.write( (Sint16 *) buf, bytes_read / sizeof(Sint16), sounds[i]->snd->GetVolume() );

		if( bytes_left > 0 )
		{
			/* This sound is finishing. */
			sounds[i]->stopping = true;
			sounds[i]->flush_pos = play_pos + (bytes_read / bytes_per_frame);
		}
	}

	mix.read((Sint16 *) buffers[b].lpData);
	MMRESULT ret = waveOutWrite(wo, &buffers[b], sizeof(buffers[b]));
  	if(ret != MMSYSERR_NOERROR)
		RageException::Throw(wo_ssprintf(ret, "waveOutWrite failed"));

	/* Increment last_cursor_pos. */
	last_cursor_pos += chunksize_frames;

	return true;
}

void RageSound_WaveOut::StartMixing( RageSoundBase *snd )
{
	sound *s = new sound;
	s->snd = snd;
	s->start_time = snd->GetStartTime();

	LockMutex L(SOUNDMAN->lock);
	sounds.push_back(s);
}

void RageSound_WaveOut::Update(float delta)
{
	LockMutex L(SOUNDMAN->lock);

	/* SoundStopped might erase sounds out from under us, so make a copy
	 * of the sound list. */
	vector<sound *> snds = sounds;
	for(unsigned i = 0; i < snds.size(); ++i)
	{
		if(!snds[i]->stopping) continue;

		if(GetPosition(snds[i]->snd) < snds[i]->flush_pos)
			continue; /* stopping but still flushing */

		/* This sound is done. */
		snds[i]->snd->StopPlaying();
	}
}

void RageSound_WaveOut::StopMixing( RageSoundBase *snd )
{
	LockMutex L(SOUNDMAN->lock);

	/* Find the sound. */
	unsigned i;
	for(i = 0; i < sounds.size(); ++i)
		if(sounds[i]->snd == snd) break;
	if(i == sounds.size())
	{
		LOG->Trace("not stopping a sound because it's not playing");
		return;
	}

	delete sounds[i];
	sounds.erase(sounds.begin()+i, sounds.begin()+i+1);
}

int64_t RageSound_WaveOut::GetPosition( const RageSoundBase *snd ) const
{
	LockMutex L(SOUNDMAN->lock);

	MMTIME tm;
	tm.wType = TIME_SAMPLES;
	MMRESULT ret = waveOutGetPosition(wo, &tm, sizeof(tm));
  	if(ret != MMSYSERR_NOERROR)
		RageException::Throw(wo_ssprintf(ret, "waveOutGetPosition failed"));

	return tm.u.sample;
}

RageSound_WaveOut::RageSound_WaveOut()
{
	shutdown = false;
	last_cursor_pos = 0;

	sound_event = CreateEvent(NULL, false, true, NULL);

	WAVEFORMATEX fmt;

	fmt.wFormatTag = WAVE_FORMAT_PCM;
    fmt.nChannels = channels;
	fmt.cbSize = 0;
	fmt.nSamplesPerSec = samplerate;
	fmt.wBitsPerSample = 16;
	fmt.nBlockAlign = fmt.nChannels * fmt.wBitsPerSample / 8;
	fmt.nAvgBytesPerSec = fmt.nSamplesPerSec * fmt.nBlockAlign;

	MMRESULT ret = waveOutOpen(&wo, WAVE_MAPPER, &fmt,
		(DWORD_PTR) sound_event, NULL, CALLBACK_EVENT);

	if(ret != MMSYSERR_NOERROR)
		RageException::ThrowNonfatal(wo_ssprintf(ret, "waveOutOpen failed"));

	for(int b = 0; b < num_chunks; ++b)
	{
		memset(&buffers[b], 0, sizeof(buffers[b]));
		buffers[b].dwBufferLength = chunksize;
		buffers[b].lpData = new char[chunksize];
		ret = waveOutPrepareHeader(wo, &buffers[b], sizeof(buffers[b]));
		if(ret != MMSYSERR_NOERROR)
			RageException::ThrowNonfatal(wo_ssprintf(ret, "waveOutPrepareHeader failed"));
		buffers[b].dwFlags |= WHDR_DONE;
	}

	MixingThread.SetName("Mixer thread");
	MixingThread.Create( MixerThread_start, this );
}

RageSound_WaveOut::~RageSound_WaveOut()
{
	/* Signal the mixing thread to quit. */
	shutdown = true;
	SetEvent( sound_event );
	LOG->Trace("Shutting down mixer thread ...");
	MixingThread.Wait();
	LOG->Trace("Mixer thread shut down.");

	CloseHandle(sound_event);
	waveOutClose(wo);

	for(int b = 0; b < num_chunks; ++b)
	{
		waveOutUnprepareHeader( wo, &buffers[b], sizeof(buffers[b]) );
		delete [] buffers[b].lpData;
	}
}

float RageSound_WaveOut::GetPlayLatency() const
{
	/* If we have a 1000-byte buffer, and we fill 100 bytes at a time, we
	 * almost always have between 900 and 1000 bytes filled; on average, 950. */
	return (buffersize_frames - chunksize_frames/2) * (1.0f / samplerate);
}

/*
 * Copyright (c) 2002-2004 by the person(s) listed below.  All rights reserved.
 *
 * Glenn Maynard
 */