/*
 *	aegis - project change supervisor
 *	Copyright (C) 1994, 1995, 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 if statements
 */

#include <aer/expr.h>
#include <aer/stmt/if.h>
#include <aer/value/boolean.h>
#include <aer/value/error.h>
#include <error.h>
#include <sub.h>
#include <trace.h>


typedef struct rpt_stmt_if_ty rpt_stmt_if_ty;
struct rpt_stmt_if_ty
{
	RPT_STMT
	rpt_expr_ty	*condition;
};


static void destruct _((rpt_stmt_ty *));

static void
destruct(sp)
	rpt_stmt_ty	*sp;
{
	rpt_stmt_if_ty	*this;

	this = (rpt_stmt_if_ty *)sp;
	rpt_expr_free(this->condition);
}


static void run _((rpt_stmt_ty *, rpt_stmt_result_ty *));

static void
run(sp, rp)
	rpt_stmt_ty	*sp;
	rpt_stmt_result_ty *rp;
{
	rpt_stmt_if_ty	*this;
	rpt_value_ty	*vp;
	rpt_value_ty	*vp2;
	int		flag;

	trace(("stmt_if::run()\n{\n"/*}*/));
	this = (rpt_stmt_if_ty *)sp;
	assert(this->nchild == 1 || this->nchild == 2);
	vp = rpt_expr_evaluate(this->condition, 1);
	if (vp->method->type == rpt_value_type_error)
	{
		rp->status = rpt_stmt_status_error;
		rp->thrown = vp;
		trace((/*{*/"}\n"));
		return;
	}
	vp2 = rpt_value_booleanize(vp);
	rpt_value_free(vp);
	if (vp2->method->type != rpt_value_type_boolean)
	{
		sub_context_ty	*scp;
		string_ty	*s;

		scp = sub_context_new();
		sub_var_set_charstar(scp, "Name", vp2->method->name);
		rpt_value_free(vp2);
		s =
			subst_intl
			(
				scp,
		      i18n("boolean value required in if statement (not $name)")
			);
		sub_context_delete(scp);
		rp->status = rpt_stmt_status_error;
		rp->thrown = rpt_value_error(this->condition->pos, s);
		str_free(s);
		trace((/*{*/"}\n"));
		return;
	}
	flag = !rpt_value_boolean_query(vp2);
	trace(("condition was %s\n", (flag ? "false" : "true")));
	rpt_value_free(vp2);
	if (flag < this->nchild)
		rpt_stmt_run(this->child[flag], rp);
	else
	{
		rp->status = rpt_stmt_status_normal;
		rp->thrown = 0;
	}
	trace((/*{*/"}\n"));
}


static rpt_stmt_method_ty method =
{
	sizeof(rpt_stmt_if_ty),
	"if",
	0, /* construct */
	destruct,
	run,
};


rpt_stmt_ty *
rpt_stmt_if(ep)
	rpt_expr_ty	*ep;
{
	rpt_stmt_if_ty	*this;

	this = (rpt_stmt_if_ty *)rpt_stmt_alloc(&method);
	this->condition = rpt_expr_copy(ep);
	return (rpt_stmt_ty *)this;
}