/*
 *                             COPYRIGHT 1999
 *
 * Mika Seppa
 * Low Temperature Laboratory
 * Helsinki University of Technology
 * SF-02150 Espoo
 * FINLAND
 *
 * http://neuro.hut.fi/~mseppa/
 *
 *
 * The program is provided as is and the author makes no warranty of any
 * kind with regard to the program, to any modified version of it, or to
 * the labels created by any version of the program, including, but not
 * limited to, the implied warranties of merchantability and fitness for
 * a particular use. The author shall not be liable for errors contained
 * in the program or in the labels or for incidental or consequential
 * damages in connection with the furnishing, performance, or use of
 * them. In no event shall the author be liable for any claim, damages or
 * other liability, whether in an action of contract, tort or otherwise,
 * arising from, out of or in connection with the program or the labels
 * created by it.
 * 
 * The program and the labels created by the program are free for any
 * non-commercial use. The program and the created bar code labels can be
 * used freely as long as no cost (in terms of money or otherwise) is
 * charged for the delivery or use of the program or the labels created
 * by the program. The program may be modified to produce labels for your
 * specific needs as long as the modified program clearly states that it
 * is a modification of the original. The modified program and the labels
 * created by the modified program must also be free and no cost may be
 * charged for the modified program or for the labels created by it.
 * 
*/

#include <stdio.h>
#include <ctype.h>

#define NumberOf(xx) (sizeof(xx)/sizeof(xx[0]))
#define MM(x)        ((x)*72.0/25.4)

#define XCOUNT  3
#define YCOUNT 10
#define XSPACE MM(10)
#define YSPACE MM(0)
#define XOFF   MM(10)
#define YOFF   MM(35)

#define THIN    1.0
#define THICK   3.0
#define SLEN    (6.0*THIN+3.0*THICK)
#define SHEIGHT (MM(line_pos[0])-MM(line_pos[1]))

#define START_SYMBOL '*'
#define END_SYMBOL   '*'

#define SYMBOLS 6

#define WIDTH  MM(56.0)
#define HEIGHT MM(21.0)

#define BORDER_LW "0"
#define LINES_LW  "2"

typedef struct {
  char c;
  int  bars;
  int  spaces;
} CodeRec, *Code;

CodeRec codes[] = {
  { '0', 0x06, 0x04 }, { '1', 0x11, 0x04 }, { '2', 0x09, 0x04 },
  { '3', 0x18, 0x04 }, { '4', 0x05, 0x04 }, { '5', 0x14, 0x04 },
  { '6', 0x0c, 0x04 }, { '7', 0x03, 0x04 }, { '8', 0x12, 0x04 },
  { '9', 0x0a, 0x04 }, { 'A', 0x11, 0x02 }, { 'B', 0x09, 0x02 },
  { 'C', 0x18, 0x02 }, { 'D', 0x05, 0x02 }, { 'E', 0x14, 0x02 },
  { 'F', 0x0c, 0x02 }, { 'G', 0x03, 0x02 }, { 'H', 0x12, 0x02 },
  { 'I', 0x0a, 0x02 }, { 'J', 0x06, 0x02 }, { 'K', 0x11, 0x01 },
  { 'L', 0x09, 0x01 }, { 'M', 0x18, 0x01 }, { 'N', 0x05, 0x01 },
  { 'O', 0x14, 0x01 }, { 'P', 0x0c, 0x01 }, { 'Q', 0x03, 0x01 },
  { 'R', 0x12, 0x01 }, { 'S', 0x0a, 0x01 }, { 'T', 0x06, 0x01 },
  { 'U', 0x11, 0x08 }, { 'V', 0x09, 0x08 }, { 'W', 0x18, 0x08 },
  { 'X', 0x05, 0x08 }, { 'Y', 0x14, 0x08 }, { 'Z', 0x0c, 0x08 },
  { '-', 0x03, 0x08 }, { '.', 0x12, 0x08 }, { ' ', 0x0a, 0x08 },
  { '$', 0x00, 0x0e }, { '/', 0x00, 0x0d }, { '+', 0x00, 0x0b },
  { '%', 0x00, 0x07 }, { '*', 0x06, 0x08 }
};

int line_pos[] = { 14.0, 6.0, 2.0 };

char *ps_header = 
"%!PS-Adobe-3.0\n\
%%Pages: 1\n\
%%EndComments\n\
%%BeginProlog\n\
%%EndProlog\n\
%%BeginSetup\n\
/Helvetica findfont 18 scalefont setfont\n\
/cshow { dup stringwidth pop -0.5 mul 0 rmoveto show } def\n\
%%EndSetup\n\
%%Page: 1 1\n\
%%BeginPageSetup\n\
%%EndPageSetup\n";

char *ps_trailer =
"%%PageTrailer\n\
showpage\n\
%%Trailer\n\
%%EOF\n";

void print_bar(FILE *fp, float xoff, float yoff, float xsize, float ysize) {
  fprintf(fp, "newpath %g %g moveto %g 0 rlineto 0 %g rlineto\n",
	  xoff, yoff, xsize, ysize);
  fprintf(fp, "%g 0 rlineto 0 %g rlineto closepath fill\n", -xsize, -ysize);
}

int find_code(char s) {
  int i;
  for(i=0;i<NumberOf(codes);i++) if (codes[i].c==s) return i;
  return -1;
}

int print_symbol(FILE *fp, float xoff, float yoff, char s) {
  int   mask = 0x10, i, j;
  Code  c;
  float f;

  if ((j=find_code(s)) == -1) return -1;
  c = &codes[j];

  for(i=0;i<5;i++) {
    f = (c->bars&mask?THICK:THIN);
    mask>>=1;
    print_bar(fp, xoff, yoff, f, SHEIGHT);
    xoff += f + (c->spaces&mask?THICK:THIN);
  }

  return j;
}

void print_label(FILE *fp, float xoff, float yoff, char txt[SYMBOLS],
		 int ccount, int csum) {
  int   i, j, c=0;
  float f, g;

  if (ccount) {
    f = WIDTH*(float)ccount/(float)SYMBOLS;
    g = HEIGHT-MM(line_pos[0]);
    fprintf(fp, "0.8 setgray newpath %g %g moveto\n", xoff,yoff+MM(line_pos[0]));
    fprintf(fp, "%g 0 rlineto 0 %g rlineto %g 0 rlineto 0 %g rlineto\n",
	    f, g, -f, -g);
    fprintf(fp, "fill 0 setgray\n");
  }
  fprintf(fp, BORDER_LW" setlinewidth newpath %g %g moveto\n", xoff, yoff);
  fprintf(fp, "%g 0 rlineto 0 %g rlineto %g 0 rlineto 0 %g rlineto\n",
	  WIDTH, HEIGHT, -WIDTH, -HEIGHT);
  fprintf(fp, "closepath stroke\n");
  for(i=0;i<NumberOf(line_pos);i++) 
    fprintf(fp,
	    LINES_LW" setlinewidth newpath %g %g moveto %g 0 rlineto stroke\n",
	    xoff, yoff+MM(line_pos[i]), WIDTH);
  for(i=0;i<SYMBOLS;i++) {
    fprintf(fp, "%g %g moveto (%c) cshow\n",
	    xoff + (WIDTH/(float)SYMBOLS)*((float)i+0.5),
	    yoff + MM(line_pos[0]) + MM(1.0), txt[i]);
  }
  f = xoff + (WIDTH-((SLEN+THIN)*(float)(SYMBOLS+1+(csum?1:0))+SLEN))*0.5;
  g = yoff + MM(line_pos[1]);
  print_symbol(fp, f, g, START_SYMBOL); f += SLEN + THIN;
  for(i=c=0;i<SYMBOLS;i++,f+=SLEN+THIN) {
    if ((j=print_symbol(fp, f, g, txt[i])) != -1) c += j;
  }
  if (csum) {
    print_symbol(fp, f, g, codes[c%43].c);
    f += SLEN+THIN;
  }
  print_symbol(fp, f, g, END_SYMBOL);
}

int check_string(char *s, int hexmode) {
  int  i, j, ret = 0;
  Code c;

  for(i=0;i<SYMBOLS;i++) {
    if (s[i]=='\0') {
      fprintf(stderr, "Error: Label not long enough. Expecting %d characters.\n",
	      SYMBOLS);
      return -1;
    }
    if (s[i]==START_SYMBOL) {
      fprintf(stderr, "Error: Cannot use start symbol '%c' in label.\n",
	      START_SYMBOL);
      ret = -1; continue;
    }
    if (s[i]==END_SYMBOL) {
      fprintf(stderr, "Error: Cannot use end symbol '%c' in label.\n",
	      END_SYMBOL);
      ret = -1; continue;
    }
    if (find_code(s[i])!=-1) continue;
    if (isalpha(s[i])) {
      j = toupper(s[i]);
      if (find_code(j)!=-1) {
	fprintf(stderr, "Warning: Character '%c' changed to '%c'.\n",
		s[i], j);
	s[i] = j;
	continue;
      }
    }
    fprintf(stderr, "Error: No barcode for character '%c'.\n", s[i]);
    ret = -1;
  }
  if (s[SYMBOLS]!='\0')
    fprintf(stderr,
	    "Warning: Cutting excess characters, only %d first used.\n",
	    SYMBOLS);

  if (ret==0) {
    for(i=SYMBOLS;i-->0;)
      if (!isdigit(s[i]) && (!hexmode || s[i]<'A' || s[i]>'F')) break;
    ret = SYMBOLS - i - 1;
  }
  
  return ret;
}

int next_label(char txt[SYMBOLS], int numbers, int hexmode) {
  int i, c=1, j;

  for(i=0,j=SYMBOLS-1;c&&(i<numbers);i++,j--) {
    if (txt[j]=='9') {
      if (hexmode) { txt[j]='A'; c=0; }
      else txt[j] = '0';
    } else if (hexmode && txt[j]=='F') {
      txt[j] = '0';
    } else { txt[j]++; c=0; }
  }
  return !c;
}

int main(int argc, char *argv[]) {
  FILE *fp = stdout;
  char  txt[SYMBOLS] = "AQ0359";
  int   numbers, x, y, c=1, csum=0, hexmode=0;
  float xoff, yoff;

  if (argc>1 && strcmp(argv[1], "-c")==0) csum=1;
  if (argc>(1+csum) && strcmp(argv[1+csum], "-h")==0) hexmode=1;
  if (!csum && argc>(1+hexmode) && strcmp(argv[1+hexmode], "-c")==0) csum=1;

  if (argc<(2+csum+hexmode)) {
    fprintf(stderr, "Usage: %s [-c] [-h] label [outfile.ps]\n", argv[0]);
    fprintf(stderr, "  -c   : Use checksum in the barcode.\n");
    fprintf(stderr, "  -h   : Increment in hexadecimals.\n");
    exit(0);
  }

  if ((numbers=check_string(argv[1+csum+hexmode], hexmode))<0) exit(1);
  memcpy(txt, argv[1+csum+hexmode], SYMBOLS);

  if (numbers!=4)
    fprintf(stderr, "Warning: Use 2 alpha and 4 digit characters for HP DLT Tape Library!\n");

  if (argc>(2+csum+hexmode) && (fp=fopen(argv[2+csum+hexmode], "w"))==NULL) {
    fprintf(stderr, "Error: Cannot open file %s for writing.\n",
	    argv[2+csum+hexmode]);
    exit(2);
  }
  
  fputs(ps_header, fp);

  for(x=0;c&&(x<XCOUNT);x++) {
    xoff = XOFF + (float)x*(WIDTH+XSPACE);
    for(y=0;c&&(y<YCOUNT);y++) {
      yoff = YOFF + (float)(YCOUNT-y-1)*(HEIGHT+YSPACE);
      print_label(fp, xoff, yoff, txt, SYMBOLS-numbers, csum);
      c = next_label(txt, numbers, hexmode);
    }
  }

  fputs(ps_trailer, fp);
  fclose(fp);
  return 0;
}