/**
 * Copyright 2010 JBoss Inc
 *
 * 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.ArrayList;
import java.util.HashSet;
import java.util.List;

import org.drools.definition.process.WorkflowProcess;
import org.drools.xml.BaseAbstractHandler;
import org.drools.xml.ExtensibleXmlParser;
import org.drools.xml.Handler;
import org.jbpm.bpmn2.core.Association;
import org.jbpm.bpmn2.core.Lane;
import org.jbpm.bpmn2.core.SequenceFlow;
import org.jbpm.process.core.context.variable.Variable;
import org.jbpm.ruleflow.core.RuleFlowProcess;
import org.jbpm.workflow.core.Node;
import org.w3c.dom.Element;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

public class LaneHandler extends BaseAbstractHandler implements Handler {

    public static final String LANES = "BPMN.Lanes";

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

            this.validPeers = new HashSet();
            this.validPeers.add(null);
            this.validPeers.add(Lane.class);
            this.validPeers.add(Variable.class);
            this.validPeers.add(Node.class);
            this.validPeers.add(SequenceFlow.class);
            this.validPeers.add(Lane.class);
            this.validPeers.add(Association.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);

        String id = attrs.getValue("id");
        String name = attrs.getValue("name");

        WorkflowProcess process = (WorkflowProcess) parser.getParent();

        List<Lane> lanes = (List<Lane>) ((RuleFlowProcess) process).getMetaData(LaneHandler.LANES);
        if (lanes == null) {
            lanes = new ArrayList<Lane>();
            ((RuleFlowProcess) process).setMetaData(LaneHandler.LANES, lanes);
        }
        Lane lane = new Lane(id);
        lane.setName(name);
        lanes.add(lane);
        return lane;
    }

    public Object end(final String uri, final String localName,
            final ExtensibleXmlParser parser) throws SAXException {
        final Element element = parser.endElementBuilder();
        Lane lane = (Lane) parser.getCurrent();
        handleLane(lane, element, uri, localName, parser);

        org.w3c.dom.Node xmlNode = element.getFirstChild();
        while (xmlNode != null) {
            String nodeName = xmlNode.getNodeName();
            if ("flowNodeRef".equals(nodeName)) {
                String flowElementRef = xmlNode.getTextContent();
                lane.addFlowElement(flowElementRef);
            }
            xmlNode = xmlNode.getNextSibling();
        }
        return lane;
    }

    protected void handleLane(final Lane lane, final Element element, final String uri,
            final String localName, final ExtensibleXmlParser parser)
            throws SAXException {
        final String x = element.getAttribute("x");
        if (x != null && x.length() != 0) {
            try {
                lane.setX(new Integer(x));
            } catch (NumberFormatException exc) {
                throw new SAXParseException("<" + localName + "> requires an Integer 'x' attribute", parser.getLocator());
            }
        }
        final String y = element.getAttribute("y");
        if (y != null && y.length() != 0) {
            try {
                lane.setY(new Integer(y));
            } catch (NumberFormatException exc) {
                throw new SAXParseException("<" + localName + "> requires an Integer 'y' attribute", parser.getLocator());
            }
        }
        final String width = element.getAttribute("width");
        if (width != null && width.length() != 0) {
            try {
                lane.setWidth(new Integer(width));
            } catch (NumberFormatException exc) {
                throw new SAXParseException("<" + localName + "> requires an Integer 'width' attribute", parser.getLocator());
            }
        }
        final String height = element.getAttribute("height");
        if (height != null && height.length() != 0) {
            try {
                lane.setHeight(new Integer(height));
            } catch (NumberFormatException exc) {
                throw new SAXParseException("<" + localName + "> requires an Integer 'height' attribute", parser.getLocator());
            }
        }
    }

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

}