/* Line breaking of UTF-8 strings.

   Copyright (C) 2001-2003, 2006-2025 Free Software Foundation, Inc.

   Written by Bruno Haible <bruno@clisp.org>, 2001.

   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/>.  */

#include <config.h>

/* Specification.  */

#include "unilbrk.h"

#include "unilbrk/internal.h"

#include "unilbrk/lbrktables.h"

#include "unistr.h"

#include "uniwidth.h"

int

u8_width_linebreaks_internal (const uint8_t *s, size_t n,

                              int width, int start_column, int at_end_columns,

                              const char *o, const char *encoding, int cr,

                              char *p)

{

  const uint8_t *s_end;

  char *last_p;

  int last_column;

  int piece_width;

  u8_possible_linebreaks_loop (s, n, encoding, cr, p);

  s_end = s + n;

  last_p = NULL;

  last_column = start_column;

  piece_width = 0;

  while (s < s_end)

    {

      ucs4_t uc;

      int count = u8_mbtouc_unsafe (&uc, s, s_end - s);

      /* Respect the override.  */

      if (o != NULL && *o != UC_BREAK_UNDEFINED)

        *p = *o;

      if (*p == UC_BREAK_POSSIBLE

          || *p == UC_BREAK_MANDATORY || *p == UC_BREAK_CR_BEFORE_LF)

        {

          /* An atomic piece of text ends here.  */

          if (last_p != NULL && last_column + piece_width > width)

            {

              /* Insert a line break.  */

              *last_p = UC_BREAK_POSSIBLE;

              last_column = 0;

            }

        }

      if (*p == UC_BREAK_MANDATORY || *p == UC_BREAK_CR_BEFORE_LF)

        {

          /* uc is a line break character.  */

          /* Start a new piece at column 0.  */

          last_p = NULL;

          last_column = 0;

          piece_width = 0;

        }

      else

        {

          /* uc is not a line break character.  */

          int w;

          if (*p == UC_BREAK_POSSIBLE)

            {

              /* Start a new piece.  */

              last_p = p;

              last_column += piece_width;

              piece_width = 0;

              /* No line break for the moment, may be turned into

                 UC_BREAK_POSSIBLE later, via last_p. */

            }

          *p = UC_BREAK_PROHIBITED;

          w = uc_width (uc, encoding);

          if (w >= 0) /* ignore control characters in the string */

            piece_width += w;

        }

      s += count;

      p += count;

      if (o != NULL)

        o += count;

    }

  /* The last atomic piece of text ends here.  */

  if (last_p != NULL && last_column + piece_width + at_end_columns > width)

    {

      /* Insert a line break.  */

      *last_p = UC_BREAK_POSSIBLE;

      last_column = 0;

    }

  return last_column + piece_width;

}

#if defined IN_LIBUNISTRING

/* For backward compatibility with older versions of libunistring.  */

# undef u8_width_linebreaks

int

u8_width_linebreaks (const uint8_t *s, size_t n,

                     int width, int start_column, int at_end_columns,

                     const char *o, const char *encoding,

                     char *p)

{

  return u8_width_linebreaks_internal (s, n,

                                       width, start_column, at_end_columns,

                                       o, encoding, -1, p);

}

#endif

int

u8_width_linebreaks_v2 (const uint8_t *s, size_t n,

                        int width, int start_column, int at_end_columns,

                        const char *o, const char *encoding,

                        char *p)

{

  return u8_width_linebreaks_internal (s, n,

                                       width, start_column, at_end_columns,

                                       o, encoding, LBP_CR, p);

}

#ifdef TEST

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

/* Read the contents of an input stream, and return it, terminated with a NUL

   byte. */

char *

read_file (FILE *stream)

{

#define BUFSIZE 4096

  char *buf = NULL;

  int alloc = 0;

  int size = 0;

  int count;

  while (! feof (stream))

    {

      if (size + BUFSIZE > alloc)

        {

          alloc = alloc + alloc / 2;

          if (alloc < size + BUFSIZE)

            alloc = size + BUFSIZE;

          buf = realloc (buf, alloc);

          if (buf == NULL)

            {

              fprintf (stderr, "out of memory\n");

              exit (1);

            }

        }

      count = fread (buf + size, 1, BUFSIZE, stream);

      if (count == 0)

        {

          if (ferror (stream))

            {

              perror ("fread");

              exit (1);

            }

        }

      else

        size += count;

    }

  buf = realloc (buf, size + 1);

  if (buf == NULL)

    {

      fprintf (stderr, "out of memory\n");

      exit (1);

    }

  buf[size] = '\0';

  return buf;

#undef BUFSIZE

}

int

main (int argc, char * argv[])

{

  if (argc == 2)

    {

      /* Insert line breaks for a given width.  */

      int width = atoi (argv[1]);

      char *input = read_file (stdin);

      int length = strlen (input);

      char *breaks = malloc (length);

      int i;

      u8_width_linebreaks_v2 ((uint8_t *) input, length, width, 0, 0, NULL, "UTF-8", breaks);

      for (i = 0; i < length; i++)

        {

          switch (breaks[i])

            {

            case UC_BREAK_POSSIBLE:

              putc ('\n', stdout);

              break;

            case UC_BREAK_MANDATORY:

              break;

            case UC_BREAK_CR_BEFORE_LF:

              break;

            case UC_BREAK_PROHIBITED:

              break;

            default:

              abort ();

            }

          putc (input[i], stdout);

        }

      free (breaks);

      return 0;

    }

  else

    return 1;

}

#endif /* TEST */