/* Perl brace format strings.

   Copyright (C) 2004-2026 Free Software Foundation, Inc.

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

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   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 General Public License for more details.

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

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

/* Written by Bruno Haible.  */

#include <config.h>

#include <stdbool.h>

#include <stdlib.h>

#include <string.h>

#include "format.h"

#include "attribute.h"

#include "xalloc.h"

#include "gettext.h"

#define _(str) gettext (str)

/* Perl brace format strings are supported by Guido Flohr's libintl-perl

   package, more precisely by the __expand and __x functions therein.

   A format string directive here consists of

     - an opening brace '{',

     - an identifier [_A-Za-z][_0-9A-Za-z]*,

     - a closing brace '}'.

 */

struct named_arg

{

  char *name;

};

struct spec

{

  size_t directives;

  size_t named_arg_count;

  struct named_arg *named

    COUNTED_BY (named_arg_count);

};

static int

named_arg_compare (const void *p1, const void *p2)

{

  return strcmp (((const struct named_arg *) p1)->name,

                 ((const struct named_arg *) p2)->name);

}

static void *

format_parse (const char *format, bool translated, char *fdi,

              char **invalid_reason)

{

  const char *const format_start = format;

  struct spec spec;

  spec.directives = 0;

  spec.named_arg_count = 0;

  spec.named = NULL;

  size_t named_allocated = 0;

  for (; *format != '\0';)

    if (*format++ == '{')

      {

        const char *f = format;

        char c;

        c = *f;

        if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')

          {

            do

              c = *++f;

            while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_'

                   || (c >= '0' && c <= '9'));

            if (c == '}')

              {

                /* A directive.  */

                FDI_SET (format - 1, FMTDIR_START);

                const char *name_start = format;

                const char *name_end = f;

                size_t n = name_end - name_start;

                char *name = XNMALLOC (n + 1, char);

                memcpy (name, name_start, n);

                name[n] = '\0';

                spec.directives++;

                if (named_allocated == spec.named_arg_count)

                  {

                    named_allocated = 2 * named_allocated + 1;

                    spec.named = (struct named_arg *) xrealloc (spec.named, named_allocated * sizeof (struct named_arg));

                  }

                size_t named_index = spec.named_arg_count++;

                spec.named[named_index].name = name;

                FDI_SET (f, FMTDIR_END);

                format = ++f;

              }

          }

      }

  /* Sort the named argument array, and eliminate duplicates.  */

  if (spec.named_arg_count > 1)

    {

      qsort (spec.named, spec.named_arg_count, sizeof (struct named_arg),

             named_arg_compare);

      /* Remove duplicates: Copy from i to j, keeping 0 <= j <= i.  */

      size_t i, j;

      for (i = j = 0; i < spec.named_arg_count; i++)

        if (j > 0 && streq (spec.named[i].name, spec.named[j-1].name))

          free (spec.named[i].name);

        else

          {

            if (j < i)

              spec.named[j].name = spec.named[i].name;

            j++;

          }

      spec.named_arg_count = j;

    }

  struct spec *result = XMALLOC (struct spec);

  *result = spec;

  return result;

}

static void

format_free (void *descr)

{

  struct spec *spec = (struct spec *) descr;

  if (spec->named != NULL)

    {

      for (size_t i = 0; i < spec->named_arg_count; i++)

        free (spec->named[i].name);

      free (spec->named);

    }

  free (spec);

}

static int

format_get_number_of_directives (void *descr)

{

  struct spec *spec = (struct spec *) descr;

  return spec->directives;

}

static bool

format_check (void *msgid_descr, void *msgstr_descr, bool equality,

              formatstring_error_logger_t error_logger, void *error_logger_data,

              const char *pretty_msgid, const char *pretty_msgstr)

{

  struct spec *spec1 = (struct spec *) msgid_descr;

  struct spec *spec2 = (struct spec *) msgstr_descr;

  bool err = false;

  if (spec1->named_arg_count + spec2->named_arg_count > 0)

    {

      size_t n1 = spec1->named_arg_count;

      size_t n2 = spec2->named_arg_count;

      /* Check the argument names in spec1 are contained in those of spec2.

         Additional arguments in spec2 are allowed; they expand to themselves

         (including the surrounding braces) at runtime.

         Both arrays are sorted.  We search for the differences.  */

      size_t i, j;

      for (i = 0, j = 0; i < n1 || j < n2; )

        {

          int cmp = (i >= n1 ? 1 :

                     j >= n2 ? -1 :

                     strcmp (spec1->named[i].name, spec2->named[j].name));

          if (cmp > 0)

            j++;

          else if (cmp < 0)

            {

              if (equality)

                {

                  if (error_logger)

                    error_logger (error_logger_data,

                                  _("a format specification for argument '%s' doesn't exist in '%s'"),

                                  spec1->named[i].name, pretty_msgstr);

                  err = true;

                  break;

                }

              else

                i++;

            }

          else

            j++, i++;

        }

    }

  return err;

}

struct formatstring_parser formatstring_perl_brace =

{

  format_parse,

  format_free,

  format_get_number_of_directives,

  NULL,

  format_check

};

#ifdef TEST

/* Test program: Print the argument list specification returned by

   format_parse for strings read from standard input.  */

#include <stdio.h>

static void

format_print (void *descr)

{

  struct spec *spec = (struct spec *) descr;

  if (spec == NULL)

    {

      printf ("INVALID");

      return;

    }

  printf ("{");

  for (size_t i = 0; i < spec->named_arg_count; i++)

    {

      if (i > 0)

        printf (", ");

      printf ("'%s'", spec->named[i].name);

    }

  printf ("}");

}

int

main ()

{

  for (;;)

    {

      char *line = NULL;

      size_t line_size = 0;

      int line_len = getline (&line, &line_size, stdin);

      if (line_len < 0)

        break;

      if (line_len > 0 && line[line_len - 1] == '\n')

        line[--line_len] = '\0';

      char *invalid_reason = NULL;

      void *descr = format_parse (line, false, NULL, &invalid_reason);

      format_print (descr);

      printf ("\n");

      if (descr == NULL)

        printf ("%s\n", invalid_reason);

      free (invalid_reason);

      free (line);

    }

  return 0;

}

/*

 * For Emacs M-x compile

 * Local Variables:

 * compile-command: "/bin/sh ../libtool --tag=CC --mode=link gcc -o a.out -static -O -g -Wall -I.. -I../gnulib-lib -I../../gettext-runtime/intl -DTEST format-perl-brace.c ../gnulib-lib/libgettextlib.la"

 * End:

 */

#endif /* TEST */