/*
 * Copyright (c) 2000-2001
 * Kevin Atkinson
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation.  Kevin Atkinson makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 *
 */

#include <stdio.h>

#if defined(__CYGWIN__) || defined (_WIN32)

#  include <io.h>
#  include <fcntl.h>

#  define SETBIN(fno)  _setmode( _fileno( fno ), _O_BINARY )

#else

#  define SETBIN(fno)

#endif

#define BUFSIZE 256

void usage ()
{
  fputs("Compresses or uncompresses sorted word lists.\n"     , stderr);
  fputs("For best result the locale should be set to C\n"     , stderr);
  fputs("before sorting by setting the environmental\n"       , stderr);
  fputs("variable LANG to \"C\" before sorting.\n"	      , stderr);
  fputs("Copyright 2001,2004 by Kevin Atkinson.\n"	      , stderr);
  fputs("Usage: word-list-compress c[ompress]|d[ecompress]\n" , stderr);
}

// PRECOND: bufsize >= 2
int get_word(FILE * in, char * w)
{
  int bufsize = BUFSIZE - 1;
  register int c;

  while (c = getc(in), c != EOF && c <= 32);
  if (c != EOF) {
    do {
      *w++ = (char)(c);
    } while (c = getc(in), c != EOF && c > 32 && --bufsize);
  }
//printf(" *** %d ***",bufsize); /******remove this line******/
//printf(" *** %d ***\n", (BUFSIZE - bufsize)); /******remove this line******/
  *w = '\0';
  ungetc(c, in);
  if (c == EOF) return 0; /* done */
  if (bufsize)  return 1; /* normal return */
  return 2;		  /* error, word larger than 255 chars */
}

int main (int argc, const char *argv[]) {

  if (argc == 2) {
    char c = argv[1][0];
    if (c == '-') c = argv[1][1];

    if (c == 'v') {
      fputs("version X\n",stderr);
      return 0;
    }

    if (c == 'c') {

      char s1[BUFSIZE];
      char s2[BUFSIZE];
      char * prev = s2;
      char * cur = s1;
      *prev = '\0';
      int errFlag;

      SETBIN (stdout);

      while ((errFlag = get_word(stdin, cur)) == 1) {
	int i = 0;
	/* get the length of the prefix */
	while (prev[i] != '\0' && prev[i] == cur[i])
	  ++i;
	if (i > 31) {
	  if (putc('\0', stdout) < 0) goto error_out_c;
	}
	if (putc(i+1, stdout) < 0) goto error_out_c;
	if (fputs(cur+i, stdout) < 0) goto error_out_c;
	if (cur == s1) {
	  prev = s1; cur = s2;
	} else {
	  prev = s2; cur = s1;
	}
      }
      if (fflush(stdout) < 0) goto error_out_c;
      if (errFlag) goto error_in_c;
      return 0;
    }

    if (c == 'd') {

      char cur[BUFSIZE+1];
      int i;
      int c;

      SETBIN (stdin);

      i = getc(stdin);
      while (i != -1 ) {
	if (i == 0)
	  i = getc(stdin);
	--i;
	if (i < 0) goto error_in_d;
	while ((c = getc(stdin)) > 32 && i < BUFSIZE)
	  cur[i++] = (char)c;
	if (i >= BUFSIZE) goto error_in_d;
	/* one "puts" faster than 2 puts */
	cur[i] = '\n'; cur[++i] = '\0';
	if (fputs(cur, stdout) < 0) goto error_out_d;
	i = c;
      }
      return 0;

     error_in_c:
     error_in_d:
      fputs("ERROR: Corrupt Input.\n", stderr);
      return 2;

     error_out_c:
     error_out_d:
      /* output space full or other output fault */
      fputs("ERROR: Output Data Error.\n", stderr);
      return 3;
    }
  }

  usage();
  return 1;
}