/*
 * 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.
 */

/* $Id$ */

package org.apache.fop.fo.flow;

import org.xml.sax.Locator;

import org.apache.fop.apps.FOPException;
import org.apache.fop.fo.FONode;
import org.apache.fop.fo.FObj;
import org.apache.fop.fo.PropertyList;
import org.apache.fop.fo.ValidationException;
import org.apache.fop.fo.properties.StringProperty;


/**
 * Class modelling the <a href="http://www.w3.org/TR/xsl/#fo_multi-toggle">
 * <code>fo:multi-toggle<code></a> property.
 */
public class MultiToggle extends FObj implements MultiCaseHandler {
    // The value of properties relevant for fo:multi-toggle (commented out for performance).
    //     private CommonAccessibility commonAccessibility;
     public StringProperty prSwitchTo;
    // End of property values

    private static boolean notImplementedWarningGiven = false;

    /**
     * Base constructor
     *
     * @param parent {@link FONode} that is the parent of this object
     */
    public MultiToggle(FONode parent) {
        super(parent);

        if (!notImplementedWarningGiven) {
            getFOValidationEventProducer().unimplementedFeature(this, getName(),
                    getName(), getLocator());
            notImplementedWarningGiven = true;
        }
    }

    /** {@inheritDoc} */
    @Override
    public void bind(PropertyList pList) throws FOPException {
        super.bind(pList);
        prSwitchTo = (StringProperty) pList.get(PR_SWITCH_TO);
    }

    /**
     * {@inheritDoc}
     * <br>XSL Content Model: (#PCDATA|%inline;|%block;)*
     */
    @Override
    protected void validateChildNode(Locator loc, String nsURI, String localName)
                throws ValidationException {
        if (FO_URI.equals(nsURI)) {
            if (!isBlockOrInlineItem(nsURI, localName)) {
                invalidChildError(loc, nsURI, localName);
            }
        }
    }

    /** {@inheritDoc} */
    @Override
    public String getLocalName() {
        return "multi-toggle";
    }

    /**
     * {@inheritDoc}
     * @return {@link org.apache.fop.fo.Constants#FO_MULTI_TOGGLE}
     */
    @Override
    public int getNameId() {
        return FO_MULTI_TOGGLE;
    }

    public void filter(MultiSwitch multiSwitch) throws FOPException {
        if (multiSwitch.getCurrentlyVisibleNode() == null) {
            multiSwitch.setCurrentlyVisibleNode(parent);
        }

        FONode currentlyVisibleMultiCase = multiSwitch.getCurrentlyVisibleNode();

        if (prSwitchTo.getString().equals("xsl-any")) {
//            NoOp
        } else if (prSwitchTo.getString().equals("xsl-preceding")) {
            FONodeIterator nodeIter = multiSwitch.getChildNodes(currentlyVisibleMultiCase);
            if (nodeIter != null) {
                if (!nodeIter.hasPrevious()) {
                    currentlyVisibleMultiCase = nodeIter.lastNode();
                } else {
                    currentlyVisibleMultiCase = nodeIter.previousNode();
                }
            }
        } else if (prSwitchTo.getString().equals("xsl-following")) {
            FONodeIterator nodeIter = multiSwitch.getChildNodes(currentlyVisibleMultiCase);
            if (nodeIter != null) {
                //Ignore the first node
                nodeIter.next();
                if (!nodeIter.hasNext()) {
                    currentlyVisibleMultiCase = nodeIter.firstNode();
                } else {
                    currentlyVisibleMultiCase = nodeIter.nextNode();
                }
            }
        } else {
            // Pick an fo:multi-case that matches a case-name...
        }

        multiSwitch.setCurrentlyVisibleNode(currentlyVisibleMultiCase);
    }
}