/*
 * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */
package com.sun.tools.internal.xjc.reader.xmlschema.parser;

import com.sun.tools.internal.xjc.reader.internalizer.AbstractReferenceFinderImpl;
import com.sun.tools.internal.xjc.reader.internalizer.DOMForest;
import com.sun.tools.internal.xjc.reader.internalizer.InternalizationLogic;
import com.sun.tools.internal.xjc.util.DOMUtils;
import com.sun.xml.internal.bind.v2.WellKnownNamespace;

import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.XMLFilterImpl;

/**
 * XML Schema specific internalization logic.
 * 
 * @author
 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
 */
public class XMLSchemaInternalizationLogic implements InternalizationLogic {

    /**
     * This filter looks for &lt;xs:import> and &lt;xs:include>
     * and parses those documents referenced by them.
     */
    private static final class ReferenceFinder extends AbstractReferenceFinderImpl {
        ReferenceFinder( DOMForest parent ) {
            super(parent);
        }
        
        protected String findExternalResource( String nsURI, String localName, Attributes atts) {
            if( WellKnownNamespace.XML_SCHEMA.equals(nsURI)
            && ("import".equals(localName) || "include".equals(localName) ) )
                return atts.getValue("schemaLocation");
            else
                return null;
        }
    }

    public XMLFilterImpl createExternalReferenceFinder(DOMForest parent) {
        return new ReferenceFinder(parent);
    }

    public boolean checkIfValidTargetNode(DOMForest parent, Element bindings, Element target) {
        return WellKnownNamespace.XML_SCHEMA.equals(target.getNamespaceURI());
    }

    public Element refineTarget(Element target) {
        // look for existing xs:annotation
        Element annotation = DOMUtils.getFirstChildElement(target, WellKnownNamespace.XML_SCHEMA, "annotation");
        if(annotation==null)
            // none exists. need to make one
            annotation = insertXMLSchemaElement( target, "annotation" );
        
        // then look for appinfo
        Element appinfo = DOMUtils.getFirstChildElement(annotation, WellKnownNamespace.XML_SCHEMA, "appinfo" );
        if(appinfo==null)
            // none exists. need to make one
            appinfo = insertXMLSchemaElement( annotation, "appinfo" );
        
        return appinfo;
    }

    /**
     * Creates a new XML Schema element of the given local name
     * and insert it as the first child of the given parent node.
     * 
     * @return
     *      Newly create element.
     */
    private Element insertXMLSchemaElement( Element parent, String localName ) {
        // use the same prefix as the parent node to avoid modifying
        // the namespace binding.
        String qname = parent.getTagName();
        int idx = qname.indexOf(':');
        if(idx==-1)     qname = localName;
        else            qname = qname.substring(0,idx+1)+localName;
        
        Element child = parent.getOwnerDocument().createElementNS( WellKnownNamespace.XML_SCHEMA, qname );
        
        NodeList children = parent.getChildNodes();
        
        if( children.getLength()==0 )
            parent.appendChild(child);
        else
            parent.insertBefore( child, children.item(0) );
        
        return child;
    }
}
