/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.log4j.varia;

import org.apache.log4j.Level;
import org.apache.log4j.spi.Filter;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.helpers.OptionConverter;

/**
 * This is a very simple filter based on level matching.
 * 
 * <p>
 * The filter admits two options <b>LevelToMatch</b> and <b>AcceptOnMatch</b>.
 * If there is an exact match between the value of the <b>LevelToMatch</b>
 * option and the level of the {@link LoggingEvent}, then the {@link #decide}
 * method returns {@link Filter#ACCEPT} in case the <b>AcceptOnMatch</b> option
 * value is set to <code>true</code>, if it is <code>false</code> then
 * {@link Filter#DENY} is returned. If there is no match, {@link Filter#NEUTRAL}
 * is returned.
 * 
 * @author Ceki G&uuml;lc&uuml;
 * 
 * @since 1.2
 */
public class LevelMatchFilter extends Filter {

    /**
     * Do we return ACCEPT when a match occurs. Default is <code>true</code>.
     */
    boolean acceptOnMatch = true;

    /**
     */
    Level levelToMatch;

    public void setLevelToMatch(String level) {
	levelToMatch = OptionConverter.toLevel(level, null);
    }

    public String getLevelToMatch() {
	return levelToMatch == null ? null : levelToMatch.toString();
    }

    public void setAcceptOnMatch(boolean acceptOnMatch) {
	this.acceptOnMatch = acceptOnMatch;
    }

    public boolean getAcceptOnMatch() {
	return acceptOnMatch;
    }

    /**
     * Return the decision of this filter.
     * 
     * Returns {@link Filter#NEUTRAL} if the <b>LevelToMatch</b> option is not set
     * or if there is not match. Otherwise, if there is a match, then the returned
     * decision is {@link Filter#ACCEPT} if the <b>AcceptOnMatch</b> property is set
     * to <code>true</code>. The returned decision is {@link Filter#DENY} if the
     * <b>AcceptOnMatch</b> property is set to false.
     * 
     */
    public int decide(LoggingEvent event) {
	if (this.levelToMatch == null) {
	    return Filter.NEUTRAL;
	}

	boolean matchOccured = false;
	if (this.levelToMatch.equals(event.getLevel())) {
	    matchOccured = true;
	}

	if (matchOccured) {
	    if (this.acceptOnMatch)
		return Filter.ACCEPT;
	    else
		return Filter.DENY;
	} else {
	    return Filter.NEUTRAL;
	}
    }
}
