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

#include "wrap.h"

/* We really should be able to pass the void * version to stdio routines
   and get automatic casting per the prototype.  Unfortunately, this does
   not work for routines which are implemented as macros - so much for
   not caring whether a routine is a macro or not! */
#define f ((FILE *)fv)

static int wrapper_close(void *fv)
{
 fclose(f);
 return(0);
}

static int wrapper_read_comment(void *fv, char *buf, int nb)
{
 int c;
 int done;

 done = 0;
 while (nb > 0)
  { c = getc(f);
    if (c == EOF) break;
    if (c == '\n')
     { while (1)
	{ c = getc(f);
	  if (c == EOF)
	   { break;
	   }
	  else if (c == '#')
	   { do
	      { c = getc(f);
	      } while ((c != EOF) && (c != '\n'));
	     if (c == EOF) goto out; /* break 2 */
	   }
	  else
	   { ungetc(c,f);
	     break;
	   }
	}
       c = '\n';
     }
    *buf++ = c;
    nb --;
    done ++;
  }
out:;
 return(done?done:feof(f)?0:-1);
}

FILE *wrap_open_comment(FILE *arg, int closeunder)
{
 return(funopen(arg,wrapper_read_comment,0,0,closeunder?wrapper_close:0));
}

static int wrapper_read_continue(void *fv, char *buf, int nb)
{
 int c;
 int done;

 done = 0;
 while (nb > 0)
  { c = getc(f);
    if (c == EOF) break;
    if (c == '\n')
     { c = getc(f);
       if (c == EOF)
	{ c = '\n';
	}
       else if ((c == ' ') || (c == '\t'))
	{ do
	   { c = getc(f);
	   } while ((c == ' ') || (c == '\t') || (c == '\n'));
	  if (c == EOF) break;
	  ungetc(c,f);
	  c = ' ';
	}
       else
	{ ungetc(c,f);
	  c = '\n';
	}
     }
    *buf++ = c;
    nb --;
    done ++;
  }
 return(done?done:feof(f)?0:-1);
}

FILE *wrap_open_continue(FILE *arg, int closeunder)
{
 return(funopen(arg,wrapper_read_continue,0,0,closeunder?wrapper_close:0));
}

typedef struct hcs HCS;
struct hcs {
  unsigned int inhdrs : 1;
  unsigned int closeunder : 1;
  FILE *fp;
  } ;

static int wrapper_read_hdrcontinue(void *arg, char *buf, int nb)
{
 HCS *h;
 int c;
 int done;

 h = arg;
 done = 0;
 while (nb > 0)
  { c = getc(h->fp);
    if (c == EOF) break;
    if (h->inhdrs)
     { if (c == '\n')
	{ c = getc(h->fp);
	  if (c == EOF)
	   { c = '\n';
	   }
	  else if ((c == ' ') || (c == '\t'))
	   { do
	      { c = getc(h->fp);
	      } while ((c == ' ') || (c == '\t') || (c == '\n'));
	     if (c == EOF) break;
	     ungetc(c,h->fp);
	     c = ' ';
	   }
	  else
	   { if (c == '\n') h->inhdrs = 0;
	     ungetc(c,h->fp);
	     c = '\n';
	   }
	}
     }
    *buf++ = c;
    nb --;
    done ++;
  }
 return(done?done:feof(h->fp)?0:-1);
}

static int wrapper_close_hdrcontinue(void *arg)
{
 if (((HCS *)arg)->closeunder) fclose(((HCS *)arg)->fp);
 free((HCS *)arg);
 return(0);
}

FILE *wrap_open_hdrcontinue(FILE *arg, int closeunder)
{
 HCS *h;
 FILE *rv;

 h = malloc(sizeof(HCS));
 h->inhdrs = 1;
 h->closeunder = !!closeunder;
 h->fp = arg;
 rv = funopen(h,wrapper_read_hdrcontinue,0,0,wrapper_close_hdrcontinue);
 if (! rv)
  { int e;
    e = errno;
    free(h);
    errno = e;
  }
 return(rv);
}