/* Store a character in UTF-8 string.

   Copyright (C) 2002, 2005-2006, 2009-2020 Free Software Foundation, Inc.

   Written by Bruno Haible <bruno@clisp.org>, 2002.

   This program is free software: you can redistribute it and/or

   modify it under the terms of either:

     * the GNU Lesser General Public License as published by the Free

       Software Foundation; either version 3 of the License, or (at your

       option) any later version.

   or

     * the GNU General Public License as published by the Free

       Software Foundation; either version 2 of the License, or (at your

       option) any later version.

   or both in parallel, as here.

   This program 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 for more details.

   You should have received a copy of the GNU Lesser General Public License

   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

#if defined IN_LIBUNISTRING

/* Tell unistr.h to declare u8_uctomb as 'extern', not 'static inline'.  */

# include "unistring-notinline.h"

#endif

/* Specification.  */

#include "unistr.h"

#include "attribute.h"

#if !HAVE_INLINE

int

u8_uctomb (uint8_t *s, ucs4_t uc, int n)

{

  if (uc < 0x80)

    {

      if (n > 0)

        {

          s[0] = uc;

          return 1;

        }

      /* else return -2, below.  */

    }

  else

    {

      int count;

      if (uc < 0x800)

        count = 2;

      else if (uc < 0x10000)

        {

          if (uc < 0xd800 || uc >= 0xe000)

            count = 3;

          else

            return -1;

        }

      else if (uc < 0x110000)

        count = 4;

      else

        return -1;

      if (n >= count)

        {

          switch (count) /* note: code falls through cases! */

            {

            case 4: s[3] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x10000;

              FALLTHROUGH;

            case 3: s[2] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x800;

              FALLTHROUGH;

            case 2: s[1] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0xc0;

          /*case 1:*/ s[0] = uc;

            }

          return count;

        }

    }

  return -2;

}

#endif