/* This software is Copyright 1989, 1990, 1992, 1993 by various individuals.
   Please see the accompanying file COPYRIGHT for details. */

#include <stdio.h>
#include <limits.h>
#include <stdarg.h>

#include "str.h"
#include "externs.h"

enum filemode {
  RM_OLD, /* old strings, possibly compressed with old table */
#define FIRSTFLAG_OLD '\1' /* also, unrecognized flag byte */
  RM_RAW, /* no compression at all */
#define FIRSTFLAG_RAW '\2'
  } ;

static const char *old_compress_table[] = {
  "e ", " t", "th", "he", "s ", " a", "ou", "in",
  "t ", " s", "er", "d ", "re", "an", "n ", " i",
  " o", "es", "st", "to", "or", "nd", "o ", "ar",
  "r ", ", ", "on", " b", "ea", "it", "u ", " w",
  "ng", "le", "is", "te", "en", "at", " c", "y ",
  "ro", " f", "oo", "al", ". ", "a ", " d", "ut",
  " h", "se", "nt", "ll", "g ", "yo", " l", " y",
  " p", "ve", "f ", "as", "om", "of", "ha", "ed",
  "h ", "hi", " r", "lo", "Yo", " m", "ne", "l ",
  "li", "de", "el", "ta", "wa", "ri", "ee", "ti",
  "no", "do", "Th", " e", "ck", "ur", "ow", "la",
  "ac", "et", "me", "il", " g", "ra", "co", "ch",
  "ma", "un", "so", "rt", "ai", "ce", "ic", "be",
  " n", "k ", "ge", "ot", "si", "pe", "tr", "wi",
  "e.", "ca", "rs", "ly", "ad", "we", "bo", "ho",
  "ir", "fo", "ke", "us", "m ", " T", "di", ".." };

static unsigned char bigraphs[256][256];
static int didinit = 0;
static char oldcbuf[16384];

static int first_read = 0;
static int first_write = 0;

static enum filemode readmode;

void newdb_str_read(void)
{
 first_read = 1;
}

void newdb_str_write(void)
{
 first_write = 1;
}

char *old_uncompress(const char *s)
{
 int c;
 char *ucp;

 if (!s || !*s) return(0);
 ucp = &oldcbuf[0];
 for (;*s;s++)
  { c = *(const unsigned char *)s;
    if (c < 128)
     { *ucp++ = c;
     }
    else
     { *ucp++ = old_compress_table[c-128][0];
       *ucp++ = old_compress_table[c-128][1];
     }
  }
 *ucp = 0;
 return(&oldcbuf[0]);
}

char *old_compress(const char *s)
{
 char *cp;
 int b;

 if (!s || !*s) return(0);
 if (! didinit)
  { int i;
    int j;
    for (i=0;i<256;i++) for (j=0;j<256;j++) bigraphs[i][j] = 0;
    for (i=0;i<128;i++)
     { bigraphs[(int)old_compress_table[i][0]][(int)old_compress_table[i][1]] = i + 128;
     }
    didinit = 1;
  }
 cp = &oldcbuf[0];
 for (;*s;s++)
  { b = bigraphs[((const unsigned char *)s)[0]][((const unsigned char *)s)[1]];
    if (b)
     { *(unsigned char *)(cp++) = b;
       s ++;
     }
    else
     { *cp++ = *s;
     }
  }
 *cp = 0;
 return(&oldcbuf[0]);
}

static void first_read_chk(char **sp)
{
 switch (**sp)
  { case FIRSTFLAG_OLD:
       readmode = RM_OLD;
       ++ *sp;
       break;
    case FIRSTFLAG_RAW:
       readmode = RM_RAW;
       ++ *sp;
       break;
    default: /* compatability - read old db files without change */
       readmode = RM_OLD;
       fprintf(stderr,"First string: %s\n",*sp);
       fprintf(stderr,"Reading db strings in compatability mode\n");
       break;
  }
 first_read = 0;
}

STR unfputs_str(char *s)
{
 if (first_read) first_read_chk(&s);
 switch (readmode)
  { case RM_OLD:
	{ int i;
	  for (i=0;s[i];i++)
	   { if (((unsigned char *)s)[i] >= 128)
	      { s = old_uncompress(s);
		break;
	      }
	   }
	  return(store_str(s));
	}
       break;
    case RM_RAW:
       return(store_str(s));
       break;
    default:
       panic("bad readmode");
       return(NOSTR); /* shut up warning about return value */
       break;
  }
}

void str_print(char *s)
{
 if (first_read) first_read_chk(&s);
 switch (readmode)
  { case RM_OLD:
	{ int i;
	  for (i=0;s[i];i++)
	   { if (((unsigned char *)s)[i] >= 128)
	      { s = old_uncompress(s);
		break;
	      }
	   }
	  record_string(s);
	}
       break;
    case RM_RAW:
       record_string(s);
       break;
    default:
       panic("bad readmode");
       break;
  }
}

void disk_write(const char *s, FILE *f)
{
 if (first_write)
  { putc(FIRSTFLAG_RAW,f);
    first_write = 0;
  }
 if (s) fputs(s,f);
}