/* GNU m4 -- A simple macro processor
   Copyright (C) 1999-2001, 2006-2010, 2013-2014, 2017 Free Software
   Foundation, Inc.

   This file is part of GNU M4.

   GNU M4 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.

   GNU M4 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 <http://www.gnu.org/licenses/>.
*/

#include <config.h>

#if TM_IN_SYS_TIME
#  include <sys/time.h>
#else
#  include <time.h>
#endif /* TM_IN_SYS_TIME */

/* Build using only the exported interfaces, unless NDEBUG is set, in
   which case use private symbols to speed things up as much as possible.  */
#ifndef NDEBUG
#  include <m4/m4module.h>
#else
#  include "m4private.h"
#endif

/*         function     macros  blind   side    minargs maxargs */
#define builtin_functions                                       \
  BUILTIN (currenttime, false,  false,  false,  0,      0  )    \
  BUILTIN (ctime,       false,  false,  false,  0,      1  )    \
  BUILTIN (gmtime,      false,  true,   false,  1,      1  )    \
  BUILTIN (localtime,   false,  true,   false,  1,      1  )    \

#define mktime_functions                                        \
  BUILTIN (mktime,      false,  true,   false,  6,      7  )    \

#define strftime_functions                                      \
  BUILTIN (strftime,    false,  true,   false,  2,      2  )    \


#define BUILTIN(handler, macros, blind, side, min, max)  M4BUILTIN (handler)
  builtin_functions
# if HAVE_MKTIME
  mktime_functions
# endif
# if HAVE_STRFTIME
  strftime_functions
# endif
#undef BUILTIN

static const m4_builtin m4_builtin_table[] =
{
#define BUILTIN(handler, macros, blind, side, min, max)                 \
  M4BUILTIN_ENTRY (handler, #handler, macros, blind, side, min, max)

  builtin_functions
# if HAVE_MKTIME
  mktime_functions
# endif
# if HAVE_STRFTIME
  strftime_functions
# endif
#undef BUILTIN

  { NULL, NULL, 0, 0, 0 },
};


void
include_time (m4 *context, m4_module *module, m4_obstack *obs)
{
  m4_install_builtins (context, module, m4_builtin_table);
}



/**
 * currenttime()
 **/
M4BUILTIN_HANDLER (currenttime)
{
  char buf[64];
  time_t now;
  int l;

  now = time (0L);
  l = sprintf (buf, "%ld", now);

  obstack_grow (obs, buf, l);
}

/**
 * ctime([SECONDS])
 **/
M4BUILTIN_HANDLER (ctime)
{
  time_t t;
  int i;
  const char *s;

  if (argc == 2)
    {
      m4_numeric_arg (context, m4_arg_info (argv), M4ARG (1), M4ARGLEN (1),
                      &i);
      t = i;
    }
  else
    t = time (0L);

  s = ctime (&t);
  obstack_grow (obs, s, 24);
}

static void
format_tm (m4_obstack *obs, struct tm *tm)
{
  m4_shipout_int (obs, tm->tm_sec);
  obstack_1grow (obs, ',');

  m4_shipout_int (obs, tm->tm_min);
  obstack_1grow (obs, ',');

  m4_shipout_int (obs, tm->tm_hour);
  obstack_1grow (obs, ',');

  m4_shipout_int (obs, tm->tm_mday);
  obstack_1grow (obs, ',');

  m4_shipout_int (obs, tm->tm_mon);
  obstack_1grow (obs, ',');

  m4_shipout_int (obs, tm->tm_year);
  obstack_1grow (obs, ',');

  m4_shipout_int (obs, tm->tm_wday);
  obstack_1grow (obs, ',');

  m4_shipout_int (obs, tm->tm_yday);
  obstack_1grow (obs, ',');

  m4_shipout_int (obs, tm->tm_isdst);
}

/**
 * gmtime(SECONDS)
 **/
M4BUILTIN_HANDLER (gmtime)
{
  time_t t;
  int i;

  if (!m4_numeric_arg (context, m4_arg_info (argv), M4ARG (1), M4ARGLEN (1),
                       &i))
    return;

  t = i;
  format_tm (obs, gmtime (&t));
}

/**
 * localtime(SECONDS)
 **/
M4BUILTIN_HANDLER (localtime)
{
  time_t t;
  int i;

  if (!m4_numeric_arg (context, m4_arg_info (argv), M4ARG (1), M4ARGLEN (1),
                       &i))
    return;

  t = i;
  format_tm (obs, localtime (&t));
}

#if HAVE_MKTIME
/**
 * mktime(SEC, MIN, HOUR, MDAY, MONTH, YEAR, [ISDST])
 **/
M4BUILTIN_HANDLER (mktime)
{
  const m4_call_info *me = m4_arg_info (argv);
  struct tm tm;
  time_t t;

  if (!m4_numeric_arg (context, me, M4ARG (1), M4ARGLEN (1), &tm.tm_sec))
    return;
  if (!m4_numeric_arg (context, me, M4ARG (2), M4ARGLEN (2), &tm.tm_min))
    return;
  if (!m4_numeric_arg (context, me, M4ARG (3), M4ARGLEN (3), &tm.tm_hour))
    return;
  if (!m4_numeric_arg (context, me, M4ARG (4), M4ARGLEN (4), &tm.tm_mday))
    return;
  if (!m4_numeric_arg (context, me, M4ARG (5), M4ARGLEN (5), &tm.tm_mon))
    return;
  if (!m4_numeric_arg (context, me, M4ARG (6), M4ARGLEN (6), &tm.tm_year))
    return;
  if (M4ARG (7) && !m4_numeric_arg (context, me, M4ARG (7), M4ARGLEN (7),
                                    &tm.tm_isdst))
    return;

  t = mktime (&tm);

  m4_shipout_int (obs, t);
}
#endif /* HAVE_MKTIME */

#if HAVE_STRFTIME
/**
 * strftime(FORMAT, SECONDS)
 **/
M4BUILTIN_HANDLER (strftime)
{
  struct tm *tm;
  time_t t;
  char *buf;
  int l;

  if (!m4_numeric_arg (context, m4_arg_info (argv), M4ARG (2), M4ARGLEN (2),
                       &l))
    return;

  t = l;
  tm = localtime (&t);

  buf = (char *) obstack_alloc (obs, 1024);
  l = strftime (buf, 1024, M4ARG (1), tm);
  obstack_grow (obs, buf, l);
}
#endif /* HAVE_STRFTIME */