/* PHP format strings.
   Copyright (C) 2001-2024 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 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/>.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdbool.h>
#include <stdlib.h>

#include "format.h"
#include "c-ctype.h"
#include "xalloc.h"
#include "xvasprintf.h"
#include "format-invalid.h"
#include "gettext.h"

#define _(str) gettext (str)

/* PHP format strings are described in
   https://www.php.net/manual/en/function.sprintf.php, and are implemented in
   php-8.1.0/ext/standard/formatted_print.c.
   A directive
   - starts with '%' or '%m$' where m is a positive integer,
   - is optionally followed by any of the characters '0', '-', ' ', or
     "'<anychar>", each of which acts as a flag,
   - is optionally followed by a width specification: a nonempty digit
     sequence,
   - is optionally followed by '.' and a precision specification: a nonempty
     digit sequence,
   - is optionally followed by a size specifier 'l', which is ignored,
   - is finished by a specifier
       - 's', that needs a string argument,
       - 'b', 'd', 'u', 'o', 'x', 'X', that need an integer argument,
       - 'e', 'E', 'f', 'F', 'g', 'G', 'h', 'H', that need a floating-point
         argument,
       - 'c', that needs a character argument.
   Additionally there is the directive '%%', which takes no argument.
   Numbered and unnumbered argument specifications can be used in the same
   string.  Numbered argument specifications have no influence on the
   "current argument index", that is incremented each time an argument is read.
 */

enum format_arg_type
{
  FAT_INTEGER,
  FAT_FLOAT,
  FAT_CHARACTER,
  FAT_STRING
};

struct numbered_arg
{
  unsigned int number;
  enum format_arg_type type;
};

struct spec
{
  unsigned int directives;
  unsigned int numbered_arg_count;
  struct numbered_arg *numbered;
};

/* Locale independent test for a decimal digit.
   Argument can be  'char' or 'unsigned char'.  (Whereas the argument of
   <ctype.h> isdigit must be an 'unsigned char'.)  */
#undef isdigit
#define isdigit(c) ((unsigned int) ((c) - '0') < 10)


static int
numbered_arg_compare (const void *p1, const void *p2)
{
  unsigned int n1 = ((const struct numbered_arg *) p1)->number;
  unsigned int n2 = ((const struct numbered_arg *) p2)->number;

  return (n1 > n2 ? 1 : n1 < n2 ? -1 : 0);
}

static void *
format_parse (const char *format, bool translated, char *fdi,
              char **invalid_reason)
{
  const char *const format_start = format;
  unsigned int directives;
  unsigned int numbered_arg_count;
  struct numbered_arg *numbered;
  unsigned int numbered_allocated;
  unsigned int unnumbered_arg_count;
  struct spec *result;

  directives = 0;
  numbered_arg_count = 0;
  numbered = NULL;
  numbered_allocated = 0;
  unnumbered_arg_count = 0;

  for (; *format != '\0';)
    if (*format++ == '%')
      {
        /* A directive.  */
        FDI_SET (format - 1, FMTDIR_START);
        directives++;

        if (*format != '%')
          {
            /* A complex directive.  */
            unsigned int number;
            enum format_arg_type type;

            number = ++unnumbered_arg_count;
            if (isdigit (*format))
              {
                const char *f = format;
                unsigned int m = 0;

                do
                  {
                    m = 10 * m + (*f - '0');
                    f++;
                  }
                while (isdigit (*f));

                if (*f == '$')
                  {
                    if (m == 0)
                      {
                        *invalid_reason = INVALID_ARGNO_0 (directives);
                        FDI_SET (f, FMTDIR_ERROR);
                        goto bad_format;
                      }
                    number = m;
                    format = ++f;
                    --unnumbered_arg_count;
                  }
              }

            /* Parse flags.  */
            for (;;)
              {
                if (*format == '0' || *format == '-' || *format == ' ')
                  format++;
                else if (*format == '\'')
                  {
                    format++;
                    if (*format == '\0')
                      {
                        *invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
                        FDI_SET (format - 1, FMTDIR_ERROR);
                        goto bad_format;
                      }
                    format++;
                  }
                else
                  break;
              }

            /* Parse width.  */
            if (isdigit (*format))
              {
                do
                  format++;
                while (isdigit (*format));
              }

            /* Parse precision.  */
            if (*format == '.')
              {
                format++;

                if (isdigit (*format))
                  {
                    do
                      format++;
                    while (isdigit (*format));
                  }
                else
                  --format;     /* will jump to bad_format */
              }

            /* Parse size.  */
            if (*format == 'l')
              format++;

            switch (*format)
              {
              case 'b': case 'd': case 'u': case 'o': case 'x': case 'X':
                type = FAT_INTEGER;
                break;
              case 'e': case 'E': case 'f': case 'F': case 'g': case 'G':
              case 'h': case 'H':
                type = FAT_FLOAT;
                break;
              case 'c':
                type = FAT_CHARACTER;
                break;
              case 's':
                type = FAT_STRING;
                break;
              default:
                if (*format == '\0')
                  {
                    *invalid_reason = INVALID_UNTERMINATED_DIRECTIVE ();
                    FDI_SET (format - 1, FMTDIR_ERROR);
                  }
                else
                  {
                    *invalid_reason =
                      INVALID_CONVERSION_SPECIFIER (directives, *format);
                    FDI_SET (format, FMTDIR_ERROR);
                  }
                goto bad_format;
              }

            if (numbered_allocated == numbered_arg_count)
              {
                numbered_allocated = 2 * numbered_allocated + 1;
                numbered = (struct numbered_arg *) xrealloc (numbered, numbered_allocated * sizeof (struct numbered_arg));
              }
            numbered[numbered_arg_count].number = number;
            numbered[numbered_arg_count].type = type;
            numbered_arg_count++;
          }

        FDI_SET (format, FMTDIR_END);

        format++;
      }

  /* Sort the numbered argument array, and eliminate duplicates.  */
  if (numbered_arg_count > 1)
    {
      unsigned int i, j;
      bool err;

      qsort (numbered, numbered_arg_count,
             sizeof (struct numbered_arg), numbered_arg_compare);

      /* Remove duplicates: Copy from i to j, keeping 0 <= j <= i.  */
      err = false;
      for (i = j = 0; i < numbered_arg_count; i++)
        if (j > 0 && numbered[i].number == numbered[j-1].number)
          {
            enum format_arg_type type1 = numbered[i].type;
            enum format_arg_type type2 = numbered[j-1].type;
            enum format_arg_type type_both;

            if (type1 == type2)
              type_both = type1;
            else
              {
                /* Incompatible types.  */
                type_both = type1;
                if (!err)
                  *invalid_reason =
                    INVALID_INCOMPATIBLE_ARG_TYPES (numbered[i].number);
                err = true;
              }

            numbered[j-1].type = type_both;
          }
        else
          {
            if (j < i)
              {
                numbered[j].number = numbered[i].number;
                numbered[j].type = numbered[i].type;
              }
            j++;
          }
      numbered_arg_count = j;
      if (err)
        /* *invalid_reason has already been set above.  */
        goto bad_format;
    }

  result = XMALLOC (struct spec);
  result->directives = directives;
  result->numbered_arg_count = numbered_arg_count;
  result->numbered = numbered;
  return result;

 bad_format:
  if (numbered != NULL)
    free (numbered);
  return NULL;
}

static void
format_free (void *descr)
{
  struct spec *spec = (struct spec *) descr;

  if (spec->numbered != NULL)
    free (spec->numbered);
  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->numbered_arg_count + spec2->numbered_arg_count > 0)
    {
      unsigned int i, j;
      unsigned int n1 = spec1->numbered_arg_count;
      unsigned int n2 = spec2->numbered_arg_count;

      /* Check that the argument numbers are the same.
         Both arrays are sorted.  We search for the first difference.  */
      for (i = 0, j = 0; i < n1 || j < n2; )
        {
          int cmp = (i >= n1 ? 1 :
                     j >= n2 ? -1 :
                     spec1->numbered[i].number > spec2->numbered[j].number ? 1 :
                     spec1->numbered[i].number < spec2->numbered[j].number ? -1 :
                     0);

          if (cmp > 0)
            {
              if (error_logger)
                error_logger (error_logger_data,
                              _("a format specification for argument %u, as in '%s', doesn't exist in '%s'"),
                              spec2->numbered[j].number, pretty_msgstr,
                              pretty_msgid);
              err = true;
              break;
            }
          else if (cmp < 0)
            {
              if (equality)
                {
                  if (error_logger)
                    error_logger (error_logger_data,
                                  _("a format specification for argument %u doesn't exist in '%s'"),
                                  spec1->numbered[i].number, pretty_msgstr);
                  err = true;
                  break;
                }
              else
                i++;
            }
          else
            j++, i++;
        }
      /* Check the argument types are the same.  */
      if (!err)
        for (i = 0, j = 0; j < n2; )
          {
            if (spec1->numbered[i].number == spec2->numbered[j].number)
              {
                if (spec1->numbered[i].type != spec2->numbered[j].type)
                  {
                    if (error_logger)
                      error_logger (error_logger_data,
                                    _("format specifications in '%s' and '%s' for argument %u are not the same"),
                                    pretty_msgid, pretty_msgstr,
                                    spec2->numbered[j].number);
                    err = true;
                    break;
                  }
                j++, i++;
              }
            else
              i++;
          }
    }

  return err;
}


struct formatstring_parser formatstring_php =
{
  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;
  unsigned int last;
  unsigned int i;

  if (spec == NULL)
    {
      printf ("INVALID");
      return;
    }

  printf ("(");
  last = 1;
  for (i = 0; i < spec->numbered_arg_count; i++)
    {
      unsigned int number = spec->numbered[i].number;

      if (i > 0)
        printf (" ");
      if (number < last)
        abort ();
      for (; last < number; last++)
        printf ("_ ");
      switch (spec->numbered[i].type)
        {
        case FAT_INTEGER:
          printf ("i");
          break;
        case FAT_FLOAT:
          printf ("f");
          break;
        case FAT_CHARACTER:
          printf ("c");
          break;
        case FAT_STRING:
          printf ("s");
          break;
        default:
          abort ();
        }
      last = number + 1;
    }
  printf (")");
}

int
main ()
{
  for (;;)
    {
      char *line = NULL;
      size_t line_size = 0;
      int line_len;
      char *invalid_reason;
      void *descr;

      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';

      invalid_reason = NULL;
      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 -DHAVE_CONFIG_H -DTEST format-php.c ../gnulib-lib/libgettextlib.la"
 * End:
 */

#endif /* TEST */
