/* 
 *  Copyright (C) 2000 - 2008 TagServlet Ltd
 *
 *  This file is part of Open BlueDragon (OpenBD) CFML Server Engine.
 *  
 *  OpenBD is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  Free Software Foundation,version 3.
 *  
 *  OpenBD 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 OpenBD.  If not, see http://www.gnu.org/licenses/
 *  
 *  Additional permission under GNU GPL version 3 section 7
 *  
 *  If you modify this Program, or any covered work, by linking or combining 
 *  it with any of the JARS listed in the README.txt (or a modified version of 
 *  (that library), containing parts covered by the terms of that JAR, the 
 *  licensors of this Program grant you additional permission to convey the 
 *  resulting work. 
 *  README.txt @ http://www.openbluedragon.org/license/README.txt
 *  
 *  http://www.openbluedragon.org/
 */

package com.naryx.tagfusion.expression.function;

import java.util.List;

import com.naryx.tagfusion.cfm.engine.cfBooleanData;
import com.naryx.tagfusion.cfm.engine.cfData;
import com.naryx.tagfusion.cfm.engine.cfEngine;
import com.naryx.tagfusion.cfm.engine.cfSession;
import com.naryx.tagfusion.cfm.engine.cfmRunTimeException;
import com.naryx.tagfusion.cfm.tag.cfOUTPUT;
import com.naryx.tagfusion.cfm.tag.cfSCRIPT;
import com.naryx.tagfusion.cfm.tag.cfTag;

/**
 * Evaluates an expression and throws an exception if the expression evaluates
 * to false; it does nothing if the expression evaluates to true.
 */

public class assertFunction extends functionBase {
	private static final long serialVersionUID = 1L;

	public assertFunction() {
		min = max = 1;
	}

	public String[] getParamInfo(){
		return new String[]{
			"Expression"
		};
	}
	
	public java.util.Map getInfo(){
		return makeInfo(
				"debugging", 
				"Evaluates an expression and throws an exception if the expression evaluates to false; it does nothing if the expression evaluates to true", 
				ReturnType.BOOLEAN );
	}

	
	public cfData execute(cfSession _session, List<cfData> parameters) throws cfmRunTimeException {
		if (!cfEngine.isAssertionsEnabled())
			return cfBooleanData.TRUE;

		boolean expr = false;

		try {
			expr = parameters.get(0).getBoolean();
		} catch (cfmRunTimeException e) {
			throwException(_session, e.getCatchData().getString("detail"));
		}

		if (!expr) {
			cfTag parent = _session.activeTag();
			if (parent instanceof cfSCRIPT) {
				throwException(_session, "Assertion Failed at line " + (parent.posLine + _session.getCFContext().getLine() - 1));
			} else if (parent instanceof cfOUTPUT) {
				throwException(_session, "Assertion Failed at line " + (parent.posLine + parent.getExpressionPosition(_session.getActiveExpression())));
			} else {
				throwException(_session, "Assertion Failed at line " + parent.posLine);
			}
		}

		return cfBooleanData.TRUE;
	}
}