/*
 *  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.ivy.plugins.trigger;

import org.apache.ivy.core.IvyContext;
import org.apache.ivy.core.event.IvyEvent;
import org.apache.ivy.core.event.IvyEventFilter;
import org.apache.ivy.core.event.IvyListener;
import org.apache.ivy.plugins.matcher.PatternMatcher;
import org.apache.ivy.util.filter.Filter;

/**
 * Base class for easy trigger implementation. This base class takes of the event filtering part,
 * the only method to implement in subclasses is {@link IvyListener#progress(IvyEvent)} which should
 * do whatever the trigger needs to do when the event occurs. This method will only be called when
 * an event matching the trigger filter occurs.
 * 
 * @since 1.4
 */
public abstract class AbstractTrigger implements Trigger {
    private Filter filter;

    private String event;

    private String expression;

    private String matcher = PatternMatcher.EXACT;

    public Filter getEventFilter() {
        if (filter == null) {
            filter = createFilter();
        }
        return filter;
    }

    private Filter createFilter() {
        return new IvyEventFilter(getEvent(), getFilter(), getPatternMatcher());
    }

    private PatternMatcher getPatternMatcher() {
        return IvyContext.getContext().getSettings().getMatcher(matcher);
    }

    public String getEvent() {
        return event;
    }

    public void setEvent(String event) {
        this.event = event;
    }

    public String getFilter() {
        return expression;
    }

    public void setFilter(String filterExpression) {
        expression = filterExpression;
    }

    public String getMatcher() {
        return matcher;
    }

    public void setMatcher(String matcher) {
        this.matcher = matcher;
    }

}