/* Conversion from UTF-8 to legacy encodings.
   Copyright (C) 2002, 2006-2007, 2009-2026 Free Software Foundation, Inc.

   This file is free software.
   It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
   You can redistribute it and/or modify it under either
     - the terms of the GNU Lesser General Public License as published
       by the Free Software Foundation, either version 3, or (at your
       option) any later version, or
     - the terms of the GNU General Public License as published by the
       Free Software Foundation; either version 2, or (at your option)
       any later version, or
     - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".

   This file 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
   Lesser General Public License and the GNU General Public License
   for more details.

   You should have received a copy of the GNU Lesser General Public
   License and of the GNU General Public License along with this
   program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <bruno@clisp.org>.  */

#include <config.h>

/* Specification.  */
#include "uniconv.h"

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

#include "c-strcaseeq.h"
#include "striconveha.h"
#include "unistr.h"

char *
u8_strconv_to_encoding (const uint8_t *string,
                        const char *tocode,
                        enum iconv_ilseq_handler handler)
{
  if (STRCASEEQ (tocode, "UTF-8", 'U','T','F','-','8',0,0,0,0))
    {
      /* Conversion from UTF-8 to UTF-8.  No need to go through iconv().  */
      size_t length = u8_strlen (string) + 1;
      if (u8_check (string, length))
        {
          errno = EILSEQ;
          return NULL;
        }
      char *result = (char *) malloc (length);
      if (result == NULL)
        {
          errno = ENOMEM;
          return NULL;
        }
      memcpy (result, (const char *) string, length);
      return result;
    }
  else
    {
      char *result = NULL;
      size_t length = 0;
      if (mem_iconveha ((const char *) string, u8_strlen (string) + 1,
                        "UTF-8", tocode,
                        handler == iconveh_question_mark, handler,
                        NULL, &result, &length) < 0)
        return NULL;
      /* Verify the result has exactly one NUL byte, at the end.  */
      if (!(length > 0 && result[length-1] == '\0'
            && strlen (result) == length-1))
        {
          free (result);
          errno = EILSEQ;
          return NULL;
        }
      return result;
    }
}
