/*
 * Copyright 2005 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.xml.internal.stream.events ;

import java.util.List;
import java.util.Map;
import java.util.HashMap;
import java.util.Iterator;
import java.util.ArrayList;
import java.util.Collection;

import javax.xml.namespace.QName;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.Attribute;
import javax.xml.namespace.NamespaceContext;
import java.io.Writer;
import com.sun.xml.internal.stream.util.ReadOnlyIterator;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.events.Namespace;

/** Implementation of StartElementEvent.
 *
 * @author Neeraj Bajaj Sun Microsystems,Inc.
 * @author K.Venugopal Sun Microsystems,Inc.
 */

public class StartElementEvent extends DummyEvent
implements StartElement {

    private Map fAttributes;
    private List fNamespaces;
    private NamespaceContext fNamespaceContext = null;
    private QName fQName;

    public StartElementEvent(String prefix, String uri, String localpart) {
        this(new QName(uri, localpart, prefix));
    }

    public StartElementEvent(QName qname) {
        fQName = qname;
        init();
    }

    public StartElementEvent(StartElement startelement) {
        this(startelement.getName());
        addAttributes(startelement.getAttributes());
        addNamespaceAttributes(startelement.getNamespaces());
    }

    protected void init() {
        setEventType(XMLStreamConstants.START_ELEMENT);
        fAttributes = new HashMap();
        fNamespaces = new ArrayList();
    }

    public QName getName() {
        return fQName;
    }

    public void setName(QName qname) {
        this.fQName = qname;
    }

    public Iterator getAttributes() {
        if(fAttributes != null){
            Collection coll = fAttributes.values();
            return new ReadOnlyIterator(coll.iterator());
        }
        return new ReadOnlyIterator();
    }

    public Iterator getNamespaces() {
        if(fNamespaces != null){
            return new ReadOnlyIterator(fNamespaces.iterator());
        }
        return new ReadOnlyIterator();
    }

    public Attribute getAttributeByName(QName qname) {
        if(qname == null)
            return null;
        return (Attribute)fAttributes.get(qname);
    }

    public String getNamespace(){
        return fQName.getNamespaceURI();
    }

    public String getNamespaceURI(String prefix) {
        //check that URI was supplied when creating this startElement event and prefix matches
        if( getNamespace() != null && fQName.getPrefix().equals(prefix)) return getNamespace();
        //else check the namespace context
        if(fNamespaceContext != null)
            return fNamespaceContext.getNamespaceURI(prefix);
        return null;
    }

    /**
     * <p>Return a <code>String</code> representation of this
     * <code>StartElement</code> formatted as XML.</p>
     *
     * @return <code>String</code> representation of this
     *   <code>StartElement</code> formatted as XML.
     */
    public String toString() {

        StringBuffer startElement = new StringBuffer();

        // open element
        startElement.append("<");
        startElement.append(nameAsString());

        // add any attributes
        if (fAttributes != null) {
            Iterator it = this.getAttributes();
            Attribute attr = null;
            while (it.hasNext()) {
                attr = (Attribute) it.next();
                startElement.append(" ");
                startElement.append(attr.toString());
            }
        }

        // add any namespaces
        if (fNamespaces != null) {
            Iterator it = fNamespaces.iterator();
            Namespace attr = null;
            while (it.hasNext()) {
                attr = (Namespace) it.next();
                startElement.append(" ");
                startElement.append(attr.toString());
            }
        }

        // close start tag
        startElement.append(">");

        // return StartElement as a String
        return startElement.toString();
    }

    /** Return this event as String
     * @return String Event returned as string.
     */
    public String nameAsString() {
        if("".equals(fQName.getNamespaceURI()))
            return fQName.getLocalPart();
        if(fQName.getPrefix() != null)
            return "['" + fQName.getNamespaceURI() + "']:" + fQName.getPrefix() + ":" + fQName.getLocalPart();
        else
            return "['" + fQName.getNamespaceURI() + "']:" + fQName.getLocalPart();
    }


    /** Gets a read-only namespace context. If no context is
     * available this method will return an empty namespace context.
     * The NamespaceContext contains information about all namespaces
     * in scope for this StartElement.
     *
     * @return the current namespace context
     */
    public NamespaceContext getNamespaceContext() {
        return fNamespaceContext;
    }

    public void setNamespaceContext(NamespaceContext nc) {
        fNamespaceContext = nc;
    }

    /** This method will write the XMLEvent as per the XML 1.0 specification as Unicode characters.
     * No indentation or whitespace should be outputted.
     *
     * Any user defined event type SHALL have this method
     * called when being written to on an output stream.
     * Built in Event types MUST implement this method,
     * but implementations MAY choose not call these methods
     * for optimizations reasons when writing out built in
     * Events to an output stream.
     * The output generated MUST be equivalent in terms of the
     * infoset expressed.
     *
     * @param writer The writer that will output the data
     * @throws XMLStreamException if there is a fatal error writing the event
     */
    public void writeAsEncodedUnicode(Writer writer) throws javax.xml.stream.XMLStreamException {
    }

    void addAttribute(Attribute attr){
        if(attr.isNamespace()){
            fNamespaces.add(attr);
        }else{
            fAttributes.put(attr.getName(),attr);
        }
    }

    void addAttributes(Iterator attrs){
        if(attrs == null)
            return;
        while(attrs.hasNext()){
            Attribute attr = (Attribute)attrs.next();
            fAttributes.put(attr.getName(),attr);
        }
    }

    void addNamespaceAttribute(Namespace attr){
        if(attr == null)
            return;
        fNamespaces.add(attr);
    }

    void addNamespaceAttributes(Iterator attrs){
        if(attrs == null)
            return;
        while(attrs.hasNext()){
            Namespace attr = (Namespace)attrs.next();
            fNamespaces.add(attr);
        }
    }

}