/* Copyright (C) 2000-2002, 2004-2005 Free Software Foundation, Inc.
   This file is part of the GNU LIBICONV Library.

   The GNU LIBICONV Library is free software; you can redistribute it
   and/or modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.

   The GNU LIBICONV Library is distributed in the hope that it will be
   useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU LIBICONV Library; see the file COPYING.LIB.
   If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
   Fifth Floor, Boston, MA 02110-1301, USA.  */

/* Create a table from CHARSET to Unicode. */

#include "config.h"

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iconv.h>
#include <errno.h>

#include "binary-io.h"

/* If nonzero, ignore conversions outside Unicode plane 0. */
static int bmp_only;

static const char* hexbuf (unsigned char buf[], unsigned int buflen)
{
  static char msg[50];
  switch (buflen) {
    case 1: sprintf(msg,"0x%02X",buf[0]); break;
    case 2: sprintf(msg,"0x%02X%02X",buf[0],buf[1]); break;
    case 3: sprintf(msg,"0x%02X%02X%02X",buf[0],buf[1],buf[2]); break;
    case 4: sprintf(msg,"0x%02X%02X%02X%02X",buf[0],buf[1],buf[2],buf[3]); break;
    default: abort();
  }
  return msg;
}

static int try (iconv_t cd, unsigned char buf[], unsigned int buflen, unsigned int* out)
{
  const char* inbuf = (const char*) buf;
  size_t inbytesleft = buflen;
  char* outbuf = (char*) out;
  size_t outbytesleft = 3*sizeof(unsigned int);
  size_t result;
  iconv(cd,NULL,NULL,NULL,NULL);
  result = iconv(cd,(ICONV_CONST char**)&inbuf,&inbytesleft,&outbuf,&outbytesleft);
  if (result != (size_t)(-1))
    result = iconv(cd,NULL,NULL,&outbuf,&outbytesleft);
  if (result == (size_t)(-1)) {
    if (errno == EILSEQ) {
      return -1;
    } else if (errno == EINVAL) {
      return 0;
    } else {
      int saved_errno = errno;
      fprintf(stderr,"%s: iconv error: ",hexbuf(buf,buflen));
      errno = saved_errno;
      perror("");
      exit(1);
    }
  } else if (result > 0) /* ignore conversions with transliteration */ {
    return -1;
  } else {
    if (inbytesleft != 0) {
      fprintf(stderr,"%s: inbytes = %ld, outbytes = %ld\n",hexbuf(buf,buflen),(long)(buflen-inbytesleft),(long)(3*sizeof(unsigned int)-outbytesleft));
      exit(1);
    }
    return (3*sizeof(unsigned int)-outbytesleft)/sizeof(unsigned int);
  }
}

/* Returns the out[] buffer as a Unicode value, formatted as 0x%04X. */
static const char* ucs4_decode (const unsigned int* out, unsigned int outlen)
{
  static char hexbuf[21];
  char* p = hexbuf;
  while (outlen > 0) {
    if (p > hexbuf)
      *p++ = ' ';
    sprintf (p, "0x%04X", out[0]);
    out += 1; outlen -= 1;
    if (bmp_only && strlen(p) > 6)
      return NULL;
    p += strlen(p);
  }
  return hexbuf;
}

int main (int argc, char* argv[])
{
  const char* charset;
  iconv_t cd;
  int search_depth;

  if (argc != 2) {
    fprintf(stderr,"Usage: table-from charset\n");
    exit(1);
  }
  charset = argv[1];

#if O_BINARY
  SET_BINARY(fileno(stdout));
#endif

  cd = iconv_open("UCS-4-INTERNAL",charset);
  if (cd == (iconv_t)(-1)) {
    perror("iconv_open");
    exit(1);
  }

  /* When testing UTF-8 or GB18030, stop at 0x10000, otherwise the output
     file gets too big. */
  bmp_only = (strcmp(charset,"UTF-8") == 0 || strcmp(charset,"GB18030") == 0);
  search_depth = (strcmp(charset,"UTF-8") == 0 ? 3 : 4);

  {
    unsigned int out[3];
    unsigned char buf[4];
    unsigned int i0, i1, i2, i3;
    int result;
    for (i0 = 0; i0 < 0x100; i0++) {
      buf[0] = i0;
      result = try(cd,buf,1,out);
      if (result < 0) {
      } else if (result > 0) {
        const char* unicode = ucs4_decode(out,result);
        if (unicode != NULL)
          printf("0x%02X\t%s\n",i0,unicode);
      } else {
        for (i1 = 0; i1 < 0x100; i1++) {
          buf[1] = i1;
          result = try(cd,buf,2,out);
          if (result < 0) {
          } else if (result > 0) {
            const char* unicode = ucs4_decode(out,result);
            if (unicode != NULL)
              printf("0x%02X%02X\t%s\n",i0,i1,unicode);
          } else {
            for (i2 = 0; i2 < 0x100; i2++) {
              buf[2] = i2;
              result = try(cd,buf,3,out);
              if (result < 0) {
              } else if (result > 0) {
                const char* unicode = ucs4_decode(out,result);
                if (unicode != NULL)
                  printf("0x%02X%02X%02X\t%s\n",i0,i1,i2,unicode);
              } else if (search_depth > 3) {
                for (i3 = 0; i3 < 0x100; i3++) {
                  buf[3] = i3;
                  result = try(cd,buf,4,out);
                  if (result < 0) {
                  } else if (result > 0) {
                    const char* unicode = ucs4_decode(out,result);
                    if (unicode != NULL)
                      printf("0x%02X%02X%02X%02X\t%s\n",i0,i1,i2,i3,unicode);
                  } else {
                    fprintf(stderr,"%s: incomplete byte sequence\n",hexbuf(buf,4));
                    exit(1);
                  }
                }
              }
            }
          }
        }
      }
    }
  }

  if (iconv_close(cd) < 0) {
    perror("iconv_close");
    exit(1);
  }

  if (ferror(stdin) || ferror(stdout) || fclose(stdout)) {
    fprintf(stderr,"I/O error\n");
    exit(1);
  }

  exit(0);
}
