/**
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed 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.jbpm.bpmn2.xml;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;

import org.drools.core.xml.BaseAbstractHandler;
import org.drools.core.xml.ExtensibleXmlParser;
import org.drools.core.xml.Handler;
import org.jbpm.bpmn2.core.*;
import org.jbpm.bpmn2.core.Error;
import org.jbpm.compiler.xml.ProcessBuildData;
import org.jbpm.ruleflow.core.RuleFlowProcess;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

/**
 * This class isn't currently used because we don't really check thrown or caught event content
 * (itemDefiniton references) to see if it matches the definition in the process.
 *
 * </p>In fact, at this moment, the whole <code><signal></code> element is ignored because that (specifying
 * event content) is it's only function.
 *
 * </p>This handler is just here for two reasons: <ol>
 * <li>So we can process <code><signal></code> elements in process definitions</li>
 * <li>When we do end up actively supporting event content, we'll need the functionality in this class</li>
 * </ol>
 */
public class SignalHandler extends BaseAbstractHandler implements Handler {

	@SuppressWarnings("unchecked")
	public SignalHandler() {
		if ((this.validParents == null) && (this.validPeers == null)) {
			this.validParents = new HashSet();
			this.validParents.add(Definitions.class);

			this.validPeers = new HashSet();
			this.validPeers.add(null);
            this.validPeers.add(ItemDefinition.class);
            this.validPeers.add(Message.class);
            this.validPeers.add(Interface.class);
            this.validPeers.add(Escalation.class);
            this.validPeers.add(Error.class);
            this.validPeers.add(Signal.class);
            this.validPeers.add(DataStore.class);
            this.validPeers.add(RuleFlowProcess.class);

			this.allowNesting = false;
		}
	}

	@SuppressWarnings("unchecked")
    public Object start(final String uri, final String localName,
			            final Attributes attrs, final ExtensibleXmlParser parser)
			throws SAXException {
		parser.startElementBuilder(localName, attrs);

		// according to the (Semantic.)xsd, both the name and structureRef are optional
		String id = attrs.getValue("id");
		String name = attrs.getValue("name"); // referred to by the signalEventDefinition.signalRef attr
		String structureRef = attrs.getValue("structureRef");

        ProcessBuildData buildData = (ProcessBuildData) parser.getData();
        Map<String, Signal> signals = (Map<String, Signal>) buildData.getMetaData("Signals");
        if (signals == null) {
            signals = new HashMap<String, Signal>();
            buildData.setMetaData("Signals", signals);
        }

        Signal s = new Signal(id, name, structureRef);
        signals.put(id, s);

		return s;
	}

	public Object end(final String uri, final String localName,
			          final ExtensibleXmlParser parser) throws SAXException {
		parser.endElementBuilder();
		return parser.getCurrent();
	}

	public Class<?> generateNodeFor() {
		return Error.class;
	}

}