/*
 *	aegis - project change supervisor
 *	Copyright (C) 1996, 1999 Peter Miller;
 *	All rights reserved.
 *
 *	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 2 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, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: functions to manipulate strftime
 */

#include <ac/time.h>

#include <aer/expr.h>
#include <aer/func/strftime.h>
#include <aer/value/error.h>
#include <aer/value/integer.h>
#include <aer/value/string.h>
#include <str.h>
#include <sub.h>


static int verify _((rpt_expr_ty *));

static int
verify(ep)
	rpt_expr_ty	*ep;
{
	return (ep->nchild == 2);
}


static rpt_value_ty *run _((rpt_expr_ty *, size_t, rpt_value_ty **));

static rpt_value_ty *
run(ep, argc, argv)
	rpt_expr_ty	*ep;
	size_t		argc;
	rpt_value_ty	**argv;
{
	string_ty	*t1;
	time_t		t2;
	rpt_value_ty	*vp1;
	rpt_value_ty	*vp2;
	rpt_value_ty	*result;
	int		nbytes;
	string_ty	*s;
	char		buffer[2000];

	if (argc >= 1)
	{
		vp1 = rpt_value_stringize(argv[0]);
		if (vp1->method->type != rpt_value_type_string)
		{
			sub_context_ty	*scp;

			scp = sub_context_new();
			sub_var_set_charstar(scp, "Function", "strftime");
			sub_var_set_charstar(scp, "Number", "1");
			sub_var_set_charstar(scp, "Name", argv[0]->method->name);
			rpt_value_free(vp1);
			s =
				subst_intl
				(
					scp,
    i18n("$function: argument $number: string value required (was given $name)")
				);
			sub_context_delete(scp);
			result = rpt_value_error(ep->pos, s);
			str_free(s);
			return result;
		}
		t1 = str_copy(rpt_value_string_query(vp1));
		rpt_value_free(vp1);
	}
	else
		t1 = str_from_c("%C");

	if (argc >= 2)
	{
		vp2 = rpt_value_integerize(argv[1]);
		if (vp2->method->type != rpt_value_type_integer)
		{
			sub_context_ty	*scp;

			scp = sub_context_new();
			rpt_value_free(vp2);
			sub_var_set_charstar(scp, "Function", "strftime");
			sub_var_set_charstar(scp, "Number", "2");
			sub_var_set_charstar(scp, "Name", argv[1]->method->name);
			s =
				subst_intl
				(
					scp,
      i18n("$function: argument $number: time value required (was given $name)")
				);
			sub_context_delete(scp);
			result = rpt_value_error(ep->pos, s);
			str_free(s);
			return result;
		}
		t2 = rpt_value_integer_query(vp2);
		rpt_value_free(vp2);
	}
	else
		t2 = 0;

	nbytes = strftime(buffer, sizeof(buffer), t1->str_text, localtime(&t2));
	if (nbytes <= 0)
	{
		sub_context_ty	*scp;

		scp = sub_context_new();
		sub_var_set_charstar(scp, "Function", "strftime");
		s = subst_intl(scp, i18n("$function: result too long"));
		sub_context_delete(scp);
		result = rpt_value_error(ep->pos, s);
		str_free(s);
	}
	else
	{
		s = str_from_c(buffer);
		result = rpt_value_string(s);
		str_free(s);
	}
	str_free(t1);
	return result;
}


rpt_func_ty rpt_func_strftime =
{
	"strftime",
	1, /* optimizable */
	verify,
	run
};