/* Lua format strings.

   Copyright (C) 2012-2026 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 Ľubomír Remák and Bruno Haible.  */

#include <config.h>

#include <stdbool.h>

#include <stdlib.h>

#include "format.h"

#include "attribute.h"

#include "gettext.h"

#include "xalloc.h"

#include "format-invalid.h"

#include "c-ctype.h"

#include "xvasprintf.h"

#define _(str) gettext (str)

/* The Lua format strings are described in the Lua manual,

   which can be found at:

   https://www.lua.org/manual/5.2/manual.html

   They are implemented in lua-5.2.4/src/lstrlib.c.

   A directive

   - starts with '%',

   - is optionally followed by any of the characters '0', '-', ' ', or

     each of which acts as a flag,

   - is optionally followed by a width specification: a nonempty digit

     sequence with at most 2 digits,

   - is optionally followed by '.' and a precision specification: an optional

     nonempty digit sequence with at most 2 digits,

   - is finished by a specifier

       - 's', 'q', that need a string argument,

       - 'd', 'i', 'o', 'u', 'X', 'x', that need an integer argument,

       - 'A', 'a', 'E', 'e', 'f', 'G', 'g', that need a floating-point argument,

       - 'c', that needs a character argument.

   Additionally there is the directive '%%', which takes no argument.

   Note: Lua does not distinguish between integer, floating-point

   and character arguments, since it has a number data type only.

   However, we should not allow users to use %d instead of %c.

   The same applies to %s and %q - we should not allow intermixing them.

 */

enum format_arg_type

{

  FAT_INTEGER,

  FAT_CHARACTER,

  FAT_FLOAT,

  FAT_STRING,

  FAT_ESCAPED_STRING

};

struct spec

{

  size_t directives;

  size_t format_args_count;

  enum format_arg_type *format_args

    COUNTED_BY (format_args_count);

};

static void *

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

              char **invalid_reason)

{

  const char *format_start = format;

  const char *fatstr = format;

  struct spec spec;

  spec.directives = 0;

  spec.format_args_count = 0;

  spec.format_args = NULL;

  size_t format_args_allocated = 0;

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

    {

      if (*fatstr++ == '%')

        {

          FDI_SET (fatstr - 1, FMTDIR_START);

          spec.directives++;

          if (*fatstr != '%')

            {

              /* Parse width. */

              if (c_isdigit (*fatstr))

                {

                  fatstr++;

                  if (c_isdigit (*fatstr))

                    fatstr++;

                }

              if (*fatstr == '.')

                {

                  fatstr++;

                  /* Parse precision. */

                  if (c_isdigit (*fatstr))

                    {

                      fatstr++;

                      if (c_isdigit (*fatstr))

                        fatstr++;

                    }

                }

              enum format_arg_type type;

              switch (*fatstr)

                {

                case 'c':

                  type = FAT_CHARACTER;

                  break;

                case 'd':

                case 'i':

                case 'o':

                case 'u':

                case 'X':

                case 'x':

                  type = FAT_INTEGER;

                  break;

                case 'a':

                case 'A':

                case 'E':

                case 'e':

                case 'f':

                case 'g':

                case 'G':

                  type = FAT_FLOAT;

                  break;

                case 's':

                  type = FAT_STRING;

                  break;

                case 'q':

                  type = FAT_ESCAPED_STRING;

                  break;

                default:

                  if (*fatstr == '\0')

                    {

                      *invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();

                      FDI_SET (fatstr - 1, FMTDIR_ERROR);

                    }

                  else

                    {

                      *invalid_reason =

                        INVALID_CONVERSION_SPECIFIER (spec.format_args_count + 1,

                                                      *fatstr);

                      FDI_SET (fatstr, FMTDIR_ERROR);

                    }

                  goto bad_format;

                }

              if (spec.format_args_count == format_args_allocated)

                {

                  format_args_allocated = 2 * format_args_allocated + 10;

                  spec.format_args =

                    xrealloc (spec.format_args,

                              format_args_allocated *

                              sizeof (enum format_arg_type));

                }

              size_t format_args_index = spec.format_args_count++;

              spec.format_args[format_args_index] = type;

            }

          FDI_SET (fatstr, FMTDIR_END);

          fatstr++;

        }

    }

  struct spec *result = XMALLOC (struct spec);

  *result = spec;

  return result;

 bad_format:

  if (spec.format_args != NULL)

    free (spec.format_args);

  return NULL;

}

static void

format_free (void *descr)

{

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

  if (spec->format_args != NULL)

    free (spec->format_args);

  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->format_args_count + spec2->format_args_count > 0)

    {

      size_t n1 = spec1->format_args_count;

      size_t n2 = spec2->format_args_count;

      /* Check that the argument counts are the same.  */

      if (n1 < n2)

        {

          if (error_logger)

            error_logger (error_logger_data,

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

                          n1 + 1, pretty_msgstr, pretty_msgid);

          err = true;

        }

      else if (n1 > n2 && equality)

        {

          if (error_logger)

            error_logger (error_logger_data,

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

                          n2 + 1, pretty_msgstr);

          err = true;

        }

      else

        {

          /* Check that the argument types are the same.  */

          if (!err)

            for (size_t i = 0; i < n2; i++)

              {

                if (spec1->format_args[i] != spec2->format_args[i])

                  {

                    if (error_logger)

                      error_logger (error_logger_data,

                                    _("format specifications in '%s' and '%s' for argument %zu are not the same"),

                                    pretty_msgid, pretty_msgstr, i + 1);

                    err = true;

                    break;

                  }

              }

        }

    }

  return err;

}

struct formatstring_parser formatstring_lua =

{

  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->format_args_count; i++)

    {

      if (i > 0)

        printf (" ");

      switch (spec->format_args[i])

        {

        case FAT_INTEGER:

          printf ("i");

          break;

        case FAT_FLOAT:

          printf ("f");

          break;

        case FAT_CHARACTER:

          printf ("c");

          break;

        case FAT_STRING:

          printf ("s");

          break;

        case FAT_ESCAPED_STRING:

          printf ("q");

          break;

        default:

          abort ();

        }

    }

  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-lua.c ../gnulib-lib/libgettextlib.la"

 * End:

 */

#endif /* TEST */