#include <stdio.h>
#include <stdlib.h>

#include "cards.h"

static void put16(unsigned short int v, FILE *f)
{
 putc((v>>8)&0xff,f);
 putc(v&0xff,f);
}

void card_allocdeck(DECK *d)
{
 d->cmap = malloc(d->ncol*sizeof(*d->cmap));
 d->face_c = malloc(CARD_C_INDEX(d,CARD_XDECK));
 d->back_c = malloc(CARD_C_INDEX(d,d->nbacks));
 d->face_bw = malloc(CARD_BW_INDEX(d,CARD_XDECK));
 d->back_bw = malloc(CARD_BW_INDEX(d,d->nbacks));
}

void card_freedeck(DECK *d)
{
 free(d->cmap);
 free(d->face_c);
 free(d->back_c);
 free(d->face_bw);
 free(d->back_bw);
}

const char *card_savedeck(FILE *f, const DECK *d)
{
 int i;

 if (ferror(f)) return("previous error writing to file");
 if (d->ncol > 255) return("deck uses too many colours");
 if (d->nbacks > 255) return("deck has too many back designs");
 if (d->xsize > 255) return("deck X size too large");
 if (d->ysize > 255) return("deck Y size too large");
 putc(0,f);
 putc(d->ncol,f);
 putc(d->nbacks,f);
 putc(d->xsize,f);
 putc(d->ysize,f);
 for (i=0;i<d->ncol;i++)
  { put16(d->cmap[i][0],f);
    put16(d->cmap[i][1],f);
    put16(d->cmap[i][2],f);
  }
 fwrite(d->back_bw,1,CARD_BW_INDEX(d,d->nbacks),f);
 fwrite(d->face_bw,1,CARD_BW_INDEX(d,CARD_XDECK),f);
 fwrite(d->back_c,1,CARD_C_INDEX(d,d->nbacks),f);
 fwrite(d->face_c,1,CARD_C_INDEX(d,CARD_XDECK),f);
 fflush(f);
 if (ferror(f)) return("error writing to file");
 return(0);
}

const char *card_loaddeck(FILE *f, DECK *d)
{
 __label__ unxerr;

 unsigned char c;
 unsigned char c2;
 int i;
 int j;

 unsigned char get(void)
  { int v;
    v = getc(f);
    if (v == EOF) goto unxerr;
    return(v);
  }

 if (0)
  {
unxerr:;
    return(ferror(f)?"unexpected error reading file":"unexpected EOF reading file");
  }
 c = get();
 if (c != 0) return("unrecognized file version");
 c = get();
 if (c > CARD_MAX_NCOL) return("file uses too many colours");
 d->ncol = c;
 c = get();
 if (c > CARD_MAX_NBACKS) return("file uses too many back designs");
 d->nbacks = c;
 c = get();
 if (c > CARD_MAX_XSIZE) return("file X size is too large");
 d->xsize = c;
 c = get();
 if (c > CARD_MAX_YSIZE) return("file Y size is too large");
 d->ysize = c;
 card_allocdeck(d);
 for (i=0;i<d->ncol;i++)
  { for (j=0;j<3;j++)
     { c = get();
       c2 = get();
       d->cmap[i][j] = (c * 256) + c2;
     }
  }
 fread(d->back_bw,1,CARD_BW_INDEX(d,d->nbacks),f);
 fread(d->face_bw,1,CARD_BW_INDEX(d,CARD_XDECK),f);
 fread(d->back_c,1,CARD_C_INDEX(d,d->nbacks),f);
 fread(d->face_c,1,CARD_C_INDEX(d,CARD_XDECK),f);
 if (ferror(f)) return("error reading from file");
 if (feof(f)) return("unexpected EOF reading from file");
 return(0);
}