/*

Name:
MLOADER.C

Description:
These routines are used to access the available module loaders

Portability:
All systems - all compilers

*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mikmod.h"


FILE *modfp;
UNIMOD of;

LOADER *firstloader=NULL;


UWORD finetune[16]={
	8363,	8413,	8463,	8529,	8581,	8651,	8723,	8757,
	7895,	7941,	7985,	8046,	8107,	8169,	8232,	8280
};





void ML_InfoLoader(void)
{
	int t;
	LOADER *l;

	/* list all registered devicedrivers: */

	for(t=1,l=firstloader; l!=NULL; l=l->next, t++){
		printf("%d. %s\n",t,l->version);
	}
}


void ML_RegisterLoader(LOADER *ldr)
{
	LOADER *l;

	if(firstloader==NULL){
		firstloader=ldr;
		ldr->next=NULL;
	}
	else{
		ldr->next=firstloader;
		firstloader=ldr;
	}
}



void *MyMalloc(size_t size)
/*
	Same as malloc, but sets error variable ml_errno when it failed
*/
{
	void *d;

	d=malloc(size);
	if(d==NULL){
		myerr="Error allocating structure";
	}
	return d;
}



void *MyCalloc(size_t nitems,size_t size)
/*
	Same as calloc, but sets error variable ml_errno when it failed
*/
{
	void *d;

	d=calloc(nitems,size);
	if(d==NULL){
		myerr="Error allocating structure";
	}
	return d;
}



BOOL ReadComment(UWORD len)
{
	int t;

	if(len){
		if(!(of.comment=(UBYTE *)MyMalloc(len+1))) return 0;
		fread(of.comment,len,1,modfp);
		of.comment[len]=0;

		/* strip any control-characters in the comment: */

		for(t=0;t<len;t++){
			if(of.comment[t]<32) of.comment[t]=' ';
		}
	}
	return 1;
}



BOOL AllocPatterns(void)
{
	int s,t,tracks=0;

	/* Allocate track sequencing array */

	if(!(of.patterns=(UWORD *)MyCalloc((ULONG)of.numpat*of.numchn,sizeof(UWORD)))) return 0;
	if(!(of.pattrows=(UWORD *)MyCalloc(of.numpat,sizeof(UWORD)))) return 0;

	for(t=0;t<of.numpat;t++){

		of.pattrows[t]=64;

		for(s=0;s<of.numchn;s++){
			of.patterns[(t*of.numchn)+s]=tracks++;
		}
	}

	return 1;
}


BOOL AllocTracks(void)
{
	if(!(of.tracks=MyCalloc(of.numtrk,sizeof(UBYTE *)))) return 0;
	return 1;
}



BOOL AllocInstruments(void)
{
	UWORD t;

	if(!(of.instruments=MyCalloc(of.numins,sizeof(INSTRUMENT)))) return 0;
	return 1;
}


BOOL AllocSamples(INSTRUMENT *i)
{
	UWORD u,n;

	if(n=i->numsmp){
		if(!(i->samples=MyCalloc(n,sizeof(SAMPLE)))) return 0;

		for(u=0; u<n; u++){
			i->samples[u].panning=128;
			i->samples[u].handle=-1;
		}
	}
	return 1;
}


char *DupStr(UBYTE *s,UWORD len)
/*
	Creates a CSTR out of a character buffer of 'len' bytes, but strips
	any terminating non-printing characters like 0, spaces etc.
*/
{
	UWORD t;
	char *d=NULL;

	/* Scan for first printing char in buffer [includes high ascii up to 254] */

	while(len){
		if(s[len-1]>0x20 && s[len-1]<0xff) break;
		len--;
	}

	if(len){

		/* When the buffer wasn't completely empty, allocate
		   a cstring and copy the buffer into that string, except
		   for any control-chars */

		if((d=malloc(len+1))!=NULL){
			for(t=0;t<len;t++) d[t]=(s[t]<32) ? ' ': s[t];
			d[t]=0;
		}
	}

	return d;
}



BOOL ML_LoadSamples(void)
{
	UWORD t,u;
	INSTRUMENT *i;
	SAMPLE *s;

	for(t=0;t<of.numins;t++){

		i=&of.instruments[t];

		for(u=0; u<i->numsmp; u++){

			s=&i->samples[u];

/*		printf("Loading Sample %d\n",t); */

		/* sample has to be loaded ? -> increase
		   number of samples and allocate memory and
		   load sample */

			if(s->length){

				if(s->seekpos){
					_mm_fseek(modfp,s->seekpos,SEEK_SET);
				}

				/* Call the sample load routine of the driver module.
				   It has to return a 'handle' (>=0) that identifies
				   the sample */

				s->handle=MD_SampleLoad(modfp,
										s->length,
										s->loopstart,
										s->loopend,
										s->flags);

				if(s->handle<0) return 0;
			}
		}
	}
	return 1;
}


BOOL ML_LoadHeader(void)
{
	BOOL ok=0;
	LOADER *l;

	/* Try to find a loader that recognizes the module */

	for(l=firstloader; l!=NULL; l=l->next){
		_mm_rewind(modfp);
		if(l->Test()) break;
	}

	if(l==NULL){
		myerr="Unknown module format.";
		return 0;
	}

	/* init unitrk routines */

	if(!UniInit()) return 0;

	/* init module loader */

	if(l->Init()){
		_mm_rewind(modfp);
		 ok=l->Load();
	}

	l->Cleanup();

	/* free unitrk allocations */

	UniCleanup();
	return ok;
}



void ML_XFreeInstrument(INSTRUMENT *i)
{
	UWORD t;

	if(i->samples!=NULL){
		for(t=0; t<i->numsmp; t++){
			if(i->samples[t].handle>=0){
				MD_SampleUnLoad(i->samples[t].handle);
			}
		}
		free(i->samples);
	}
	if(i->insname!=NULL) free(i->insname);
}



void ML_FreeEx(UNIMOD *mf)
{
	UWORD t;

	if(mf->modtype!=NULL) free(mf->modtype);

	if(mf->patterns!=NULL) free(mf->patterns);
	if(mf->pattrows!=NULL) free(mf->pattrows);

	if(mf->tracks!=NULL){
		for(t=0;t<mf->numtrk;t++){
			if(mf->tracks[t]!=NULL) free(mf->tracks[t]);
		}
		free(mf->tracks);
	}

	if(mf->instruments!=NULL){
		for(t=0;t<mf->numins;t++){
			ML_XFreeInstrument(&mf->instruments[t]);
		}
		free(mf->instruments);
	}

	if(mf->songname!=NULL) free(mf->songname);
	if(mf->comment!=NULL) free(mf->comment);
}



/******************************************

	Next are the user-callable functions

******************************************/


void ML_Free(UNIMOD *mf)
{
	if(mf!=NULL){
		ML_FreeEx(mf);
		free(mf);
	}
}




UNIMOD *ML_LoadFP(FILE *fp)
{
	int t;
	UNIMOD *mf;

	/* init fileptr, clear errorcode, clear static modfile: */

	modfp=fp;
	myerr=NULL;
	memset(&of,0,sizeof(UNIMOD));

	/* init panning array */

	for(t=0;t<32;t++){
		of.panning[t]=((t+1)&2)?255:0;
	}

	if(!ML_LoadHeader()){
		ML_FreeEx(&of);
		return NULL;
	}

	if(!ML_LoadSamples()){
		ML_FreeEx(&of);
		return NULL;
	}

	if(!(mf=MyCalloc(1,sizeof(UNIMOD)))){
		ML_FreeEx(&of);
		return NULL;
	}

	/* Copy the static UNIMOD contents
	into the dynamic UNIMOD struct */

	memcpy(mf,&of,sizeof(UNIMOD));

	return mf;
}



UNIMOD *ML_LoadFN(char *filename)
{
	FILE *fp;
	UNIMOD *mf;

	if((fp=fopen(filename,"rb"))==NULL){
		myerr="Error opening file";
		return NULL;
	}

	mf=ML_LoadFP(fp);
	fclose(fp);

	return mf;
}