/*	MikMod sound library
	(c) 1998, 1999 Miodrag Vallat and others - see file AUTHORS for
	complete list.

	This library is free software; you can redistribute it and/or modify
	it under the terms of the GNU Library General Public License as
	published by the Free Software Foundation; either version 2 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 Library General Public License for more details.
 
	You should have received a copy of the GNU Library 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.
*/

/*==============================================================================

  $Id: load_amf.c,v 1.18 1999/02/08 07:24:02 miod Exp $

  DMP Advanced Module Format loader

==============================================================================*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <string.h>

#include <mikmod_internals.h>

/*========== Module structure */

typedef struct AMFHEADER {
	UBYTE id[3];			/* AMF file marker */
	UBYTE version;			/* upper major, lower nibble minor version number */
	CHAR  songname[32];		/* ASCIIZ songname */
	UBYTE numsamples;		/* number of samples saved */
	UBYTE numorders;
	UWORD numtracks;		/* number of tracks saved */
	UBYTE numchannels;		/* number of channels used  */
	SBYTE panpos[32];		/* voice pan positions */
	UBYTE songbpm;
	UBYTE songspd;
} AMFHEADER;

typedef struct AMFSAMPLE {
	UBYTE type;
	CHAR  samplename[32];
	CHAR  filename[13];
	ULONG offset;
	ULONG length;
	UWORD c2spd;
	UBYTE volume;
	ULONG reppos;
	ULONG repend;
} AMFSAMPLE;

typedef struct AMFNOTE {
	UBYTE note,instr,volume,fxcnt;
	UBYTE effect[3];
	SBYTE parameter[3];
} AMFNOTE;

/*========== Loader variables */

static AMFHEADER *mh = NULL;
#define AMFTEXTLEN 22
static CHAR AMF_Version[AMFTEXTLEN+1] = "DSMI Module Format 0.0";
static AMFNOTE *track = NULL;

/*========== Loader code */

BOOL AMF_Test(void)
{
	UBYTE id[3],ver;

	if(!_mm_read_UBYTES(id,3,modreader)) return 0;
	if(memcmp(id,"AMF",3)) return 0;

	ver=_mm_read_UBYTE(modreader);
	if((ver>=10)&&(ver<=14)) return 1;
	return 0;
}

BOOL AMF_Init(void)
{
	if(!(mh=(AMFHEADER*)_mm_malloc(sizeof(AMFHEADER)))) return 0;
	if(!(track=(AMFNOTE*)_mm_calloc(64,sizeof(AMFNOTE)))) return 0;

	return 1;
}

void AMF_Cleanup(void)
{
	if(mh) free(mh);
	if(track) free(track);

	mh = NULL;
	track = NULL;
}

static BOOL AMF_UnpackTrack(MREADER* modreader)
{
	ULONG tracksize;
	UBYTE row,cmd;
	SBYTE arg;

	/* empty track */
	memset(track,0,64*sizeof(AMFNOTE));

	/* read packed track */
	if (modreader) {
		tracksize=_mm_read_I_UWORD(modreader);
		tracksize+=((ULONG)_mm_read_UBYTE(modreader))<<16;
		if (tracksize)
			while(tracksize--) {
				row=_mm_read_UBYTE(modreader);
				cmd=_mm_read_UBYTE(modreader);
				arg=_mm_read_SBYTE(modreader);
				/* unexpected end of track */
				if(!tracksize) {
					if((row==0xff)&&(cmd==0xff)&&(arg==-1))
						break;
					/* the last triplet should be FF FF FF, but this is not
					   always the case... maybe a bug in m2amf ? 
					else
						return 0;
					*/

				}
				/* invalid row (probably unexpected end of row) */
				if (row>=64)
					return 0;
				if (cmd<0x7f) {
					/* note, vol */
					track[row].note=cmd;
					track[row].volume=(UBYTE)arg+1;
				} else
				  if (cmd==0x7f) {
					/* duplicate row */
					if ((arg<0)&&(row+arg>=0)) {
						memcpy(track+row,track+(row+arg),sizeof(AMFNOTE));
					}
				} else
				  if (cmd==0x80) {
					/* instr */
					track[row].instr=arg+1;
				} else
				  if (cmd==0x83) {
					/* volume without note */
					track[row].volume=(UBYTE)arg+1;
				} else 
				  if(track[row].fxcnt<3) {
					/* effect, param */
					if(cmd>0x97)
						return 0;
					track[row].effect[track[row].fxcnt]=cmd&0x7f;
					track[row].parameter[track[row].fxcnt]=arg;
					track[row].fxcnt++;
				} else
					return 0;
			}
	}
	return 1;
}

static UBYTE* AMF_ConvertTrack(void)
{
	int row;

	/* convert track */
	UniReset();
	for (row=0;row<64;row++) {
		if (track[row].instr)  UniInstrument(track[row].instr-1);
		if (track[row].note>OCTAVE) UniNote(track[row].note-OCTAVE);
		if (track[row].volume) UniVolEffect(VOL_VOLUME,track[row].volume-1);

		/* AMF effects */
		while(track[row].fxcnt--) {
			SBYTE inf=track[row].parameter[track[row].fxcnt];

			switch(track[row].effect[track[row].fxcnt]) {
				case 1: /* Set speed */
					UniEffect(UNI_S3MEFFECTA,inf);
					break;
				case 2: /* Volume slide */
					if(inf) {
						UniWrite(UNI_S3MEFFECTD);
						if (inf>=0)
							UniWrite((inf&0xf)<<4);
						else
							UniWrite((-inf)&0xf);
					}
					break;
				/* effect 3, set channel volume, done in UnpackTrack */
				case 4: /* Porta up/down */
					if(inf) {
						if(inf>0)
							UniEffect(UNI_S3MEFFECTE,inf);
						else
							UniEffect(UNI_S3MEFFECTF,-inf);
					}
					break;
				/* effect 5, "Porta abs", not supported */
				case 6: /* Porta to note */
					UniEffect(UNI_ITEFFECTG,inf);
					break;
				case 7: /* Tremor */
					UniEffect(UNI_S3MEFFECTI,inf);
					break;
				case 8: /* Arpeggio */
					UniPTEffect(0x0,inf);
					break;
				case 9: /* Vibrato */
					UniPTEffect(0x4,inf);
					break;
				case 0xa: /* Porta + Volume slide */
					UniPTEffect(0x3,0);
					if(inf) {
						UniWrite(UNI_S3MEFFECTD);
						if (inf>=0)
							UniWrite((inf&0xf)<<4);
						else
							UniWrite((-inf)&0xf);
					}
					break;
				case 0xb: /* Vibrato + Volume slide */
					UniPTEffect(0x4,0);
					if(inf) {
						UniWrite(UNI_S3MEFFECTD);
						if (inf>=0)
							UniWrite((inf&0xf)<<4);
						else
							UniWrite((-inf)&0xf);
					}
					break;
				case 0xc: /* Pattern break (in hex) */
					UniPTEffect(0xd,inf);
					break;
				case 0xd: /* Pattern jump */
					UniPTEffect(0xb,inf);
					break;
				/* effect 0xe, "Sync", not supported */
				case 0xf: /* Retrig */
					UniEffect(UNI_S3MEFFECTQ,inf&0xf);
					break;
				case 0x10: /* Sample offset */
					UniPTEffect(0x9,inf);
					break;
				case 0x11: /* Fine volume slide */
					if(inf) {
						UniWrite(UNI_S3MEFFECTD);
						if (inf>=0)
							UniWrite((inf&0xf)<<4|0xf);
						else
							UniWrite(0xf0|((-inf)&0xf));
					}
					break;
				case 0x12: /* Fine portamento */
					if(inf) {
						if(inf>0)
							UniEffect(UNI_S3MEFFECTE,0xf0|(inf&0xf));
						else
							UniEffect(UNI_S3MEFFECTF,0xf0|((-inf)&0xf));
					}
					break;
				case 0x13: /* Delay note */
					UniPTEffect(0xe,0xd0|(inf&0xf));
					break;
				case 0x14: /* Note cut */
					UniPTEffect(0xc,0);
					break;
				case 0x15: /* Set tempo */
					UniEffect(UNI_S3MEFFECTT,inf);
					break;
				case 0x16: /* Extra fine portamento */
					if(inf) {
						if(inf>0)
							UniEffect(UNI_S3MEFFECTE,0xe0|((inf>>2)&0xf));
						else
							UniEffect(UNI_S3MEFFECTF,0xe0|(((-inf)>>2)&0xf));
					}
					break;
				case 0x17: /* Panning */
					if (inf>64)
						UniEffect(UNI_ITEFFECTS0,0x91); /* surround */
					else
						UniPTEffect(0x8,(inf==64)?255:(inf+64)<<1);
					break;
			}
			
		}
		UniNewline();
	}
	return UniDup();
}

BOOL AMF_Load(BOOL curious)
{
	int t,u,realtrackcnt,realsmpcnt;
	AMFSAMPLE s;
	SAMPLE *q;
	UWORD *track_remap;
	ULONG samplepos;
	int channel_remap[16];

	/* try to read module header  */
	_mm_read_UBYTES(mh->id,3,modreader);
	mh->version     =_mm_read_UBYTE(modreader);
	_mm_read_string(mh->songname,32,modreader);
	mh->numsamples  =_mm_read_UBYTE(modreader);
	mh->numorders   =_mm_read_UBYTE(modreader);
	mh->numtracks   =_mm_read_I_UWORD(modreader);
	mh->numchannels =_mm_read_UBYTE(modreader);
	if((!mh->numchannels)||(mh->numchannels>(mh->version>=12?32:16))) {
		_mm_errno=MMERR_NOT_A_MODULE;
		return 0;
	}

	if(mh->version>=11) {
		memset(mh->panpos,0,32);
		_mm_read_SBYTES(mh->panpos,(mh->version>=13)?32:16,modreader);
	} else
		_mm_read_UBYTES(channel_remap,16,modreader);

	if (mh->version>=13) {
		mh->songbpm=_mm_read_UBYTE(modreader);
		if(mh->songbpm<32) {
			_mm_errno=MMERR_NOT_A_MODULE;
			return 0;
		}
		mh->songspd=_mm_read_UBYTE(modreader);
		if(mh->songspd>32) {
			_mm_errno=MMERR_NOT_A_MODULE;
			return 0;
		}
	} else {
		mh->songbpm=125;
		mh->songspd=6;
	}

	if(_mm_eof(modreader)) {
		_mm_errno = MMERR_LOADING_HEADER;
		return 0;
	}

	/* set module variables */
	of.initspeed = mh->songspd;
	of.inittempo = mh->songbpm;
	AMF_Version[AMFTEXTLEN-3]='0'+(mh->version/10);
	AMF_Version[AMFTEXTLEN-1]='0'+(mh->version%10);
	of.modtype   = strdup(AMF_Version);
	of.numchn    = mh->numchannels;
	of.numtrk    = mh->numorders*mh->numchannels;
	if(mh->numtracks>of.numtrk) of.numtrk=mh->numtracks;
	of.songname  = DupStr(mh->songname,32,1);
	of.numpos    = mh->numorders;
	of.numpat    = mh->numorders;
	of.reppos    = 0;
	of.flags    |= UF_S3MSLIDES;
	for(t=0;t<32;t++) {
		if(mh->panpos[t]>64) of.panning[t]=PAN_SURROUND;
		else if(mh->panpos[t]==64) of.panning[t]=255;
		else of.panning[t]=(mh->panpos[t]+64)<<1;
	}
	of.numins=of.numsmp=mh->numsamples;

	if(!AllocPositions(of.numpos)) return 0;
	for(t=0;t<of.numpos;t++)
		of.positions[t]=t;

	if(!AllocTracks()) return 0;
	if(!AllocPatterns()) return 0;

	/* read AMF order table */
	for (t=0;t<of.numpat;t++) {
		if (mh->version>=14)
			/* track size */
			of.pattrows[t]=_mm_read_I_UWORD(modreader);
		if (mh->version>=10)
			_mm_read_I_UWORDS(of.patterns+(t*of.numchn),of.numchn,modreader);
		else
			for(u=0;u<of.numchn;u++)
				of.patterns[t*of.numchn+channel_remap[u]]=_mm_read_I_UWORD(modreader);
	}
	if(_mm_eof(modreader)) {
		_mm_errno = MMERR_LOADING_HEADER;
		return 0;
	}

	/* read sample information */
	if(!AllocSamples()) return 0;
	q=of.samples;
	for(t=0;t<of.numins;t++) {
		/* try to read sample info */
		s.type=_mm_read_UBYTE(modreader);
		_mm_read_string(s.samplename,32,modreader);
		_mm_read_string(s.filename,13,modreader);
		s.offset    =_mm_read_I_ULONG(modreader);
		s.length    =_mm_read_I_ULONG(modreader);
		s.c2spd     =_mm_read_I_UWORD(modreader);
		if(s.c2spd==8368) s.c2spd=8363;
		s.volume    =_mm_read_UBYTE(modreader);
		if(mh->version>=11) {
			s.reppos    =_mm_read_I_ULONG(modreader);
			s.repend    =_mm_read_I_ULONG(modreader);
		} else {
			s.reppos    =_mm_read_I_UWORD(modreader);
			s.repend    =s.length;
		}

		if(_mm_eof(modreader)) {
			_mm_errno = MMERR_LOADING_SAMPLEINFO; 
			return 0;
		}

		q->samplename = DupStr(s.samplename,32,1);
		q->speed     = s.c2spd;
		q->volume    = s.volume;
		if (s.type) {
			q->seekpos   = s.offset;
			q->length    = s.length;
			q->loopstart = s.reppos;
			q->loopend   = s.repend;
			if((s.repend-s.reppos)>2) q->flags |= SF_LOOP;
		}
		q++;
	}

	/* read track table */
	if(!(track_remap=_mm_calloc(mh->numtracks+1,sizeof(UWORD))))
		return 0;
	_mm_read_I_UWORDS(track_remap+1,mh->numtracks,modreader);
	if(_mm_eof(modreader)) {
		free(track_remap);
		_mm_errno=MMERR_LOADING_TRACK;
		return 0;
	}

	for(realtrackcnt=t=0;t<=mh->numtracks;t++)
		if (realtrackcnt<track_remap[t])
			realtrackcnt=track_remap[t];
	for(t=0;t<of.numpat*of.numchn;t++)
		of.patterns[t]=(of.patterns[t]<=mh->numtracks)?
		               track_remap[of.patterns[t]]-1:realtrackcnt;

	free(track_remap);

	/* unpack tracks */
	for(t=0;t<realtrackcnt;t++) {
		if(_mm_eof(modreader)) {
			_mm_errno = MMERR_LOADING_TRACK;
			return 0;
		}
		if (!AMF_UnpackTrack(modreader)) {
			_mm_errno = MMERR_LOADING_TRACK;
			return 0;
		}
		if(!(of.tracks[t]=AMF_ConvertTrack()))
			return 0;
	}
	/* add en extra void track */
	UniReset();
	for(t=0;t<64;t++) UniNewline();
	of.tracks[realtrackcnt++]=UniDup();
	for(t=realtrackcnt;t<of.numtrk;t++) of.tracks[t]=NULL;

	/* compute sample offsets */
	samplepos=_mm_ftell(modreader);
	for(realsmpcnt=t=0;t<of.numsmp;t++)
		if(realsmpcnt<of.samples[t].seekpos)
			realsmpcnt=of.samples[t].seekpos;
	for(t=1;t<=realsmpcnt;t++) {
		q=of.samples;
		while(q->seekpos!=t) q++;
		q->seekpos=samplepos;
		samplepos+=q->length;
	}
		
	return 1;
}

CHAR *AMF_LoadTitle(void)
{
	CHAR s[32];

	_mm_fseek(modreader,4,SEEK_SET);
	if(!_mm_read_UBYTES(s,32,modreader)) return NULL;

	return(DupStr(s,32,1));
}

/*========== Loader information */

MLOADER load_amf={
	NULL,
	"AMF",
	"DSMI AMF loader v1.0",
	AMF_Init,
	AMF_Test,
	AMF_Load,
	AMF_Cleanup,
	AMF_LoadTitle
};
