/*
 * Copyright (c) 2005, 2006, Oracle and/or its affiliates. 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.xml.internal.stream.events;

import com.sun.org.apache.xerces.internal.impl.PropertyManager;
import java.util.List;
import javax.xml.stream.util.XMLEventAllocator;
import javax.xml.stream.*;
import javax.xml.stream.events.*;
import javax.xml.XMLConstants;
import javax.xml.namespace.QName;
import com.sun.org.apache.xerces.internal.util.NamespaceContextWrapper;
import com.sun.org.apache.xerces.internal.util.NamespaceSupport;

/**
 * Implementation of XMLEvent Allocator.
 * @author Neeraj.bajaj@sun.com, k.venugopal@sun.com
 */
public class XMLEventAllocatorImpl implements XMLEventAllocator {

    /** Creates a new instance of XMLEventAllocator */
    public XMLEventAllocatorImpl() {
    }

    public javax.xml.stream.events.XMLEvent allocate(javax.xml.stream.XMLStreamReader xMLStreamReader) throws javax.xml.stream.XMLStreamException {
        if(xMLStreamReader == null )
            throw new XMLStreamException("Reader cannot be null");
        //        allocate is not supposed to change the state of the reader so we shouldn't be calling next.
        //        return getNextEvent(xMLStreamReader);
        return getXMLEvent(xMLStreamReader);
    }

    public void allocate(javax.xml.stream.XMLStreamReader xMLStreamReader, javax.xml.stream.util.XMLEventConsumer xMLEventConsumer) throws javax.xml.stream.XMLStreamException {
        XMLEvent currentEvent = getXMLEvent(xMLStreamReader);
        if(currentEvent != null )
            xMLEventConsumer.add(currentEvent);

        return;
    }

    public javax.xml.stream.util.XMLEventAllocator newInstance() {
        return new XMLEventAllocatorImpl();
    }

    //REVISIT: shouldn't we be using XMLEventFactory to create events.
    XMLEvent getXMLEvent(XMLStreamReader streamReader){
        XMLEvent event = null;
        //returns the current event
        int eventType = streamReader.getEventType();
        switch(eventType){

            case XMLEvent.START_ELEMENT:{
                StartElementEvent startElementEvent = new StartElementEvent(getQName(streamReader));
                fillAttributes(startElementEvent,streamReader);
                //we might have different XMLStreamReader so check every time for the namespace aware property
                //we should be setting namespace related values only when isNamespaceAware is 'true'
                if( ((Boolean)streamReader.getProperty(XMLInputFactory.IS_NAMESPACE_AWARE)).booleanValue() ){
                    fillNamespaceAttributes(startElementEvent, streamReader);
                    setNamespaceContext(startElementEvent,streamReader);
                }

                startElementEvent.setLocation(streamReader.getLocation());
                event = startElementEvent ;
                break;
            }
            case XMLEvent.END_ELEMENT:{
                EndElementEvent endElementEvent = new EndElementEvent(getQName(streamReader));
                endElementEvent.setLocation(streamReader.getLocation());

                if( ((Boolean)streamReader.getProperty(XMLInputFactory.IS_NAMESPACE_AWARE)).booleanValue() ){
                    fillNamespaceAttributes(endElementEvent,streamReader);
                }
                event = endElementEvent ;
                break;
            }
            case XMLEvent.PROCESSING_INSTRUCTION:{
                ProcessingInstructionEvent piEvent = new ProcessingInstructionEvent(streamReader.getPITarget(),streamReader.getPIData());
                piEvent.setLocation(streamReader.getLocation());
                event = piEvent ;
                break;
            }
            case XMLEvent.CHARACTERS:{
                CharacterEvent cDataEvent = new CharacterEvent(streamReader.getText());
                cDataEvent.setLocation(streamReader.getLocation());
                event = cDataEvent ;
                break;
            }
            case XMLEvent.COMMENT:{
                CommentEvent commentEvent = new CommentEvent(streamReader.getText());
                commentEvent.setLocation(streamReader.getLocation());
                event = commentEvent ;
                break;
            }
            case XMLEvent.START_DOCUMENT:{
                StartDocumentEvent sdEvent = new StartDocumentEvent();
                sdEvent.setVersion(streamReader.getVersion());
                sdEvent.setEncoding(streamReader.getEncoding());
                if(streamReader.getCharacterEncodingScheme() != null){
                    sdEvent.setDeclaredEncoding(true);
                }else{
                    sdEvent.setDeclaredEncoding(false);
                }
                sdEvent.setStandalone(streamReader.isStandalone());
                sdEvent.setLocation(streamReader.getLocation());
                event = sdEvent ;
                break;
            }
            case XMLEvent.END_DOCUMENT:{
                EndDocumentEvent endDocumentEvent = new EndDocumentEvent() ;
                endDocumentEvent.setLocation(streamReader.getLocation());
                event = endDocumentEvent ;
                break;
            }
            case XMLEvent.ENTITY_REFERENCE:{
                EntityReferenceEvent entityEvent =  new EntityReferenceEvent(streamReader.getLocalName(), new EntityDeclarationImpl(streamReader.getLocalName(),streamReader.getText()));
                entityEvent.setLocation(streamReader.getLocation());
                event = entityEvent;
                break;

            }
            case XMLEvent.ATTRIBUTE:{
                event = null ;
                break;
            }
            case XMLEvent.DTD:{
                DTDEvent dtdEvent = new DTDEvent(streamReader.getText());
                dtdEvent.setLocation(streamReader.getLocation());
                List entities = (List)streamReader.getProperty(PropertyManager.STAX_ENTITIES);
                if (entities != null && entities.size() != 0) dtdEvent.setEntities(entities);
                List notations = (List)streamReader.getProperty(PropertyManager.STAX_NOTATIONS);
                if (notations != null && notations.size() != 0) dtdEvent.setNotations(notations);
                event = dtdEvent;
                break;
            }
            case XMLEvent.CDATA:{
                CharacterEvent cDataEvent = new CharacterEvent(streamReader.getText(),true);
                cDataEvent.setLocation(streamReader.getLocation());
                event = cDataEvent ;
                break;
            }
            case XMLEvent.SPACE:{
                CharacterEvent spaceEvent = new CharacterEvent(streamReader.getText(),false,true);
                spaceEvent.setLocation(streamReader.getLocation());
                event = spaceEvent ;
                break;
            }
        }
        return event ;
    }

    //this function is not used..
    protected XMLEvent getNextEvent(XMLStreamReader streamReader) throws XMLStreamException{
        //advance the reader to next event.
        streamReader.next();
        return getXMLEvent(streamReader);
    }

    protected void fillAttributes(StartElementEvent event,XMLStreamReader xmlr){

        int len = xmlr.getAttributeCount();
        QName qname = null;
        AttributeImpl attr = null;
        NamespaceImpl nattr = null;
        for(int i=0; i<len ;i++){
            qname = xmlr.getAttributeName(i);
            //this method doesn't include namespace declarations
            //so we can be sure that there wont be any namespace declaration as part of this function call
            //we can avoid this check - nb.
            /**
             * prefix = qname.getPrefix();
             * localpart = qname.getLocalPart();
             * if (prefix.equals(XMLConstants.XMLNS_ATTRIBUTE) ) {
             * attr = new NamespaceImpl(localpart,xmlr.getAttributeValue(i));
             * }else if (prefix.equals(XMLConstants.DEFAULT_NS_PREFIX)){
             * attr = new NamespaceImpl(xmlr.getAttributeValue(i));
             * }else{
             * attr = new AttributeImpl();
             * attr.setName(qname);
             * }
             **/
            attr = new AttributeImpl();
            attr.setName(qname);
            attr.setAttributeType(xmlr.getAttributeType(i));
            attr.setSpecified(xmlr.isAttributeSpecified(i));
            attr.setValue(xmlr.getAttributeValue(i));
            event.addAttribute(attr);
        }
    }

    protected void fillNamespaceAttributes(StartElementEvent event,XMLStreamReader xmlr){
        int count = xmlr.getNamespaceCount();
        String uri = null;
        String prefix = null;
        NamespaceImpl attr = null;
        for(int i=0;i< count;i++){
            uri = xmlr.getNamespaceURI(i);
            prefix = xmlr.getNamespacePrefix(i);
            if(prefix == null){
                prefix = XMLConstants.DEFAULT_NS_PREFIX;
            }
            attr = new NamespaceImpl(prefix,uri);
            event.addNamespaceAttribute(attr);
        }
    }

    protected void fillNamespaceAttributes(EndElementEvent event,XMLStreamReader xmlr){
        int count = xmlr.getNamespaceCount();
        String uri = null;
        String prefix = null;
        NamespaceImpl attr = null;
        for(int i=0;i< count;i++){
            uri = xmlr.getNamespaceURI(i);
            prefix = xmlr.getNamespacePrefix(i);
            if(prefix == null){
                prefix = XMLConstants.DEFAULT_NS_PREFIX;
            }
            attr = new NamespaceImpl(prefix,uri);
            event.addNamespace(attr);
        }
    }

    //Revisit : Creating a new Namespacecontext for now.
    //see if we can do better job.
    private void setNamespaceContext(StartElementEvent event , XMLStreamReader xmlr){
        NamespaceContextWrapper contextWrapper =(NamespaceContextWrapper) xmlr.getNamespaceContext();
        NamespaceSupport ns = new NamespaceSupport(contextWrapper.getNamespaceContext());
        event.setNamespaceContext(new NamespaceContextWrapper(ns));
    }

    private QName getQName(XMLStreamReader xmlr) {
        return new QName(xmlr.getNamespaceURI(), xmlr.getLocalName(),
                xmlr.getPrefix());
    }
}