/* -*- mode: c++; tab-width: 4; c-basic-offset: 3; c-file-style: "linux" -*- */
//
// Copyright (c) 2008, Wei Mingzhi <whistler_wmz@users.sf.net>.
// All rights reserved.
//
// 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/>.
//

#include "global.h"
#include "players.h"
#include "sound.h"

#include "resampler.h"
#include "adplug/opl.h"
#include "adplug/demuopl.h"
#include "adplug/dbemuopl.h"
#if PAL_HAS_MAME
#include "adplug/emuopl.h"
#endif
#include "adplug/surroundopl.h"
#include "adplug/rix.h"

extern "C" BOOL g_fNoMusic;

typedef struct tagRIXPLAYER :
	public MUSICPLAYER
{
   Copl                      *opl;
   CrixPlayer                *rix;
   void                      *resampler[2];
   BYTE                       buf[(PAL_MAX_SAMPLERATE + 69) / 70 * sizeof(short) * 2];
   LPBYTE                     pos;
   INT                        iCurrentMusic; // current playing music number
   INT                        iNextMusic; // the next music number to switch to
   DWORD                      dwStartFadeTime;
   DWORD                      dwFadeLength;
   enum { NONE, FADE_IN, FADE_OUT } FadeType; // fade in or fade out ?
   BOOL                       fLoop;
   BOOL                       fNextLoop;
   BOOL                       fReady;
} RIXPLAYER, *LPRIXPLAYER;

static VOID
RIX_FillBuffer(
	VOID      *object,
	LPBYTE     stream,
	INT        len
)
/*++
	Purpose:

	Fill the background music into the sound buffer. Called by the SDL sound
	callback function only (sound.c: SOUND_FillAudio).

	Parameters:

	[OUT] stream - pointer to the stream buffer.

	[IN]  len - Length of the buffer.

	Return value:

	None.

--*/
{
	INT       i, l, volume = gpGlobals->iVolume * 3 / 4;
	UINT      t = SDL_GetTicks();
	LPRIXPLAYER pRixPlayer = (LPRIXPLAYER)object;

	if (pRixPlayer == NULL || !pRixPlayer->fReady)
	{
		//
		// Not initialized
		//
		return;
	}

	//
	// fading in or fading out
	//
	switch (pRixPlayer->FadeType)
	{
	case RIXPLAYER::FADE_IN:
		if (t >= pRixPlayer->dwStartFadeTime + pRixPlayer->dwFadeLength)
		{
			pRixPlayer->FadeType = RIXPLAYER::NONE;
		}
		else
		{
			volume = (INT)(volume * (t - pRixPlayer->dwStartFadeTime) / (FLOAT)pRixPlayer->dwFadeLength);
		}
		break;
	case RIXPLAYER::FADE_OUT:
		if (pRixPlayer->iCurrentMusic == -1 || t >= pRixPlayer->dwStartFadeTime + pRixPlayer->dwFadeLength)
		{
			//
			// There is no current playing music, or fading time has passed.
			// Start playing the next one.
			//
			if (pRixPlayer->iNextMusic > 0)
			{
				pRixPlayer->iCurrentMusic = pRixPlayer->iNextMusic;
				pRixPlayer->iNextMusic = -1;
				pRixPlayer->fLoop = pRixPlayer->fNextLoop;
				pRixPlayer->FadeType = RIXPLAYER::FADE_IN;
				pRixPlayer->dwStartFadeTime = t;
				pRixPlayer->opl->init();
				pRixPlayer->rix->rewind(pRixPlayer->iCurrentMusic);
				if (pRixPlayer->resampler[0]) resampler_clear(pRixPlayer->resampler[0]);
				if (pRixPlayer->resampler[1]) resampler_clear(pRixPlayer->resampler[1]);
			}
			else
			{
				pRixPlayer->iCurrentMusic = -1;
				pRixPlayer->FadeType = RIXPLAYER::NONE;
			}
			return;
		}
		else
		{
			volume = (INT)(volume * (1.0f - (t - pRixPlayer->dwStartFadeTime) / (FLOAT)pRixPlayer->dwFadeLength));
		}
		break;
	default:
		if (pRixPlayer->iCurrentMusic <= 0)
		{
			//
			// No current playing music
			//
			return;
		}
	}

	//
	// Fill the buffer with sound data
	//
	int buf_max_len = gpGlobals->iSampleRate / 70 * gpGlobals->iAudioChannels * sizeof(short);
	while (len > 0)
	{
		if (pRixPlayer->pos == NULL ||
			pRixPlayer->pos - pRixPlayer->buf >= buf_max_len)
		{
			pRixPlayer->pos = pRixPlayer->buf;
			if (!pRixPlayer->rix->update())
			{
				if (!pRixPlayer->fLoop)
				{
					//
					// Not loop, simply terminate the music
					//
					pRixPlayer->iCurrentMusic = -1;
					if (pRixPlayer->FadeType != RIXPLAYER::FADE_OUT && pRixPlayer->iNextMusic == -1)
					{
						pRixPlayer->FadeType = RIXPLAYER::NONE;
					}
					return;
				}
				pRixPlayer->rix->rewind(pRixPlayer->iCurrentMusic);
				if (!pRixPlayer->rix->update())
				{
					//
					// Something must be wrong
					//
					pRixPlayer->iCurrentMusic = -1;
					pRixPlayer->FadeType = RIXPLAYER::NONE;
					return;
				}
			}
			int sample_count = gpGlobals->iSampleRate / 70;
			if (pRixPlayer->resampler[0])
			{
				unsigned int samples_written = 0;
				short *finalBuf = (short*)pRixPlayer->buf;

				while (sample_count)
				{
					int to_write = resampler_get_free_count(pRixPlayer->resampler[0]);
					if (to_write)
					{
						short *tempBuf = (short*)_alloca(to_write * gpGlobals->iAudioChannels * sizeof(short));
						pRixPlayer->opl->update(tempBuf, to_write);
						for (int i = 0; i < to_write; i++)
							for (int j = 0; j < gpGlobals->iAudioChannels; j++)
								resampler_write_sample(pRixPlayer->resampler[j], tempBuf[i * gpGlobals->iAudioChannels + j]);
					}

					int to_get = resampler_get_sample_count(pRixPlayer->resampler[0]);
					if (to_get > sample_count) to_get = sample_count;
					for (int i = 0; i < to_get; i++)
						for (int j = 0; j < gpGlobals->iAudioChannels; j++)
							finalBuf[samples_written++] = resampler_get_and_remove_sample(pRixPlayer->resampler[j]);
					sample_count -= to_get;
				}
			}
			else
			{
				pRixPlayer->opl->update((short *)(pRixPlayer->buf), sample_count);
			}
		}

		l = buf_max_len - (pRixPlayer->pos - pRixPlayer->buf);
		if (len < l)
		{
			l = len;
		}

		//
		// Put audio data into buffer and adjust volume
		// WARNING: for signed 16-bit little-endian only
		//
		SHORT* ptr = (SHORT*)stream;
		for (i = 0; i < (int)(l / sizeof(SHORT)); i++)
		{
			*ptr++ = SDL_SwapLE16((int)(*(SHORT *)(pRixPlayer->pos)) * volume / SDL_MIX_MAXVOLUME);
			pRixPlayer->pos += sizeof(SHORT);
		}
		stream = (LPBYTE)ptr;
		len -= l;
	}
}

static VOID
RIX_Shutdown(
	VOID     *object
)
/*++
	Purpose:

	Shutdown the RIX player subsystem.

	Parameters:

	None.

	Return value:

	None.

--*/
{
	if (object != NULL)
	{
		LPRIXPLAYER pRixPlayer = (LPRIXPLAYER)object;
		pRixPlayer->fReady = FALSE;
		for (int i = 0; i < gpGlobals->iAudioChannels; i++)
			if (pRixPlayer->resampler[i])
				resampler_delete(pRixPlayer->resampler[i]);
		delete pRixPlayer->rix;
		delete pRixPlayer->opl;
		delete pRixPlayer;
	}
}

static BOOL
RIX_Play(
	VOID     *object,
	INT       iNumRIX,
	BOOL      fLoop,
	FLOAT     flFadeTime
)
/*++
	Purpose:

	Start playing the specified music.

	Parameters:

	[IN]  iNumRIX - number of the music. 0 to stop playing current music.

	[IN]  fLoop - Whether the music should be looped or not.

	[IN]  flFadeTime - the fade in/out time when switching music.

	Return value:

	None.

--*/
{
	LPRIXPLAYER pRixPlayer = (LPRIXPLAYER)object;

	//
	// Check for NULL pointer.
	//
	if (pRixPlayer == NULL)
	{
		return FALSE;
	}

	//
	// Stop the current CD music.
	//
	SOUND_PlayCDA(-1);

	if (iNumRIX == pRixPlayer->iCurrentMusic && pRixPlayer->iNextMusic == -1)
	{
		/* Will play the same music without any pending play changes,
		   just change the loop attribute */
		pRixPlayer->fLoop = fLoop;
		return TRUE;
	}

	if (pRixPlayer->FadeType != RIXPLAYER::NONE)
	{
		/* There is a previous running fading out or fading in.
		Start time should be adjusted for a seamless effect. */
		DWORD dwFadeLength = (DWORD)(flFadeTime * 1000) / 2, now = SDL_GetTicks();
		if (pRixPlayer->FadeType == RIXPLAYER::FADE_OUT)
		{
			if (now >= pRixPlayer->dwStartFadeTime + pRixPlayer->dwFadeLength)
			{
				/* Fading out has been completed, so the next call of RIX_FillBuffer should just start fading in. */
				pRixPlayer->dwStartFadeTime = now - dwFadeLength;
			}
			else
			{
				/* Fading out is in progress, so the next call of RIX_FillBuffer should start fading out with the same volume. */
				pRixPlayer->dwStartFadeTime = now - (DWORD)ceil((double)dwFadeLength * (now - pRixPlayer->dwStartFadeTime) / pRixPlayer->dwFadeLength);
			}
		}
		else
		{
			if (now >= pRixPlayer->dwStartFadeTime + pRixPlayer->dwFadeLength)
			{
				/* Fading in has been completed, so the next call of RIX_FillBuffer just need to start fading out. */
				pRixPlayer->dwStartFadeTime = now;
			}
			else
			{
				/* Fading in is in progress, so the next call of RIX_FillBuffer should just start fading out with the same volume. */
				pRixPlayer->dwStartFadeTime = now - (DWORD)ceil((double)dwFadeLength * (1.0 - (double)(now - pRixPlayer->dwStartFadeTime) / pRixPlayer->dwFadeLength));
			}
		}
		pRixPlayer->dwFadeLength = dwFadeLength;
	}
	else
	{
		pRixPlayer->dwStartFadeTime = SDL_GetTicks();
		pRixPlayer->dwFadeLength = (DWORD)(flFadeTime * 1000) / 2;
	}

	pRixPlayer->iNextMusic = iNumRIX;
	pRixPlayer->FadeType = RIXPLAYER::FADE_OUT;
	pRixPlayer->fNextLoop = fLoop;
	pRixPlayer->fReady = TRUE;

	return TRUE;
}

LPMUSICPLAYER
RIX_Init(
	LPCSTR     szFileName
	)
	/*++
	Purpose:

	Initialize the RIX player subsystem.

	Parameters:

	[IN]  szFileName - Filename of the mus.mkf file.

	Return value:

	0 if success, -1 if cannot allocate memory, -2 if file not found.

	--*/
{
	LPRIXPLAYER pRixPlayer = new RIXPLAYER;
	if (pRixPlayer == NULL)
	{
		return NULL;
	}
	else
	{
		memset(pRixPlayer, 0, sizeof(RIXPLAYER));
		pRixPlayer->FillBuffer = RIX_FillBuffer;
		pRixPlayer->Shutdown = RIX_Shutdown;
		pRixPlayer->Play = RIX_Play;
	}

	if (gpGlobals->fUseSurroundOPL)
	{
		switch (gpGlobals->eOPLType)
		{
		case OPL_DOSBOX_OLD:
			pRixPlayer->opl = new CSurroundopl(
				new CDemuopl(gpGlobals->iOPLSampleRate, true, false),
				new CDemuopl(gpGlobals->iOPLSampleRate, true, false),
				true, gpGlobals->iOPLSampleRate, gpGlobals->dSurroundOPLOffset);
			break;
		case OPL_DOSBOX:
			pRixPlayer->opl = new CSurroundopl(
				new CDBemuopl(gpGlobals->iOPLSampleRate, true, false),
				new CDBemuopl(gpGlobals->iOPLSampleRate, true, false),
				true, gpGlobals->iOPLSampleRate, gpGlobals->dSurroundOPLOffset);
			break;
		case OPL_MAME:
			pRixPlayer->opl = new CSurroundopl(
				new CEmuopl(gpGlobals->iOPLSampleRate, true, false),
				new CEmuopl(gpGlobals->iOPLSampleRate, true, false),
				true, gpGlobals->iOPLSampleRate, gpGlobals->dSurroundOPLOffset);
			break;
		}
	}
	else
	{
		switch (gpGlobals->eOPLType)
		{
		case OPL_DOSBOX_OLD:
			pRixPlayer->opl = new CDemuopl(gpGlobals->iOPLSampleRate, true, gpGlobals->iAudioChannels == 2);
			break;
		case OPL_DOSBOX:
			pRixPlayer->opl = new CDBemuopl(gpGlobals->iOPLSampleRate, true, gpGlobals->iAudioChannels == 2);
			break;
		case OPL_MAME:
			pRixPlayer->opl = new CEmuopl(gpGlobals->iOPLSampleRate, true, gpGlobals->iAudioChannels == 2);
			break;
		}
	}

	if (pRixPlayer->opl == NULL)
	{
		delete pRixPlayer;
		return NULL;
	}

	pRixPlayer->rix = new CrixPlayer(pRixPlayer->opl);
	if (pRixPlayer->rix == NULL)
	{
		delete pRixPlayer->opl;
		delete pRixPlayer;
		return NULL;
	}

	//
	// Load the MKF file.
	//
	if (!pRixPlayer->rix->load(szFileName, CProvider_Filesystem()))
	{
		delete pRixPlayer->rix;
		delete pRixPlayer->opl;
		delete pRixPlayer;
		pRixPlayer = NULL;
		return NULL;
	}

	if (gpGlobals->iOPLSampleRate != gpGlobals->iSampleRate)
	{
		for (int i = 0; i < gpGlobals->iAudioChannels; i++)
		{
			pRixPlayer->resampler[i] = resampler_create();
			resampler_set_quality(pRixPlayer->resampler[i], SOUND_IsIntegerConversion(gpGlobals->iOPLSampleRate) ? RESAMPLER_QUALITY_MIN : gpGlobals->iResampleQuality);
			resampler_set_rate(pRixPlayer->resampler[i], (double)gpGlobals->iOPLSampleRate / (double)gpGlobals->iSampleRate);
		}
	}

#if USE_RIX_EXTRA_INIT
	if (gpGlobals->pExtraFMRegs && gpGlobals->pExtraFMVals)
	{
		pRixPlayer->rix->set_extra_init(gpGlobals->pExtraFMRegs, gpGlobals->pExtraFMVals, gpGlobals->dwExtraLength);
	}
#endif

	//
	// Success.
	//
	pRixPlayer->FadeType = RIXPLAYER::NONE;
	pRixPlayer->iCurrentMusic = pRixPlayer->iNextMusic = -1;
	pRixPlayer->pos = NULL;
	pRixPlayer->fLoop = FALSE;
	pRixPlayer->fNextLoop = FALSE;
	pRixPlayer->fReady = FALSE;

	return pRixPlayer;
}