/**
    *    Copyright 2011 meltmedia
    *
    *    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.xchain.framework.sax;
  
  import org.xml.sax.helpers.DefaultHandler;
  import org.xml.sax.Attributes;
  import org.xml.sax.helpers.AttributesImpl;
  import org.xml.sax.ext.LexicalHandler;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  /**
   * The SaxEventRecorder is a DefaultHandler implementation that will simply record all incoming SAX events.  The events are stored as SaxEvent objects.
   * The EventList is in the same order as the original SAX events.  By default no SAX events are tracked.  Types of event tracking can be enabled with {@link #setTrackDocumentEvents(boolean)},
   * {@link #setTrackElementEvents(boolean)}, {@link #setTrackCharactersEvents(boolean)}, and {@link #setTrackPrefixMappingEvents(boolean)}.
   *
   * @author Christian Trimble
   * @author Devon Tackett
   */
  public class SaxEventRecorder
    extends DefaultHandler
    implements LexicalHandler
  {
    /** The list of recorded SAX events. */
    protected List<SaxEvent> eventList = new ArrayList<SaxEvent>();
    /** Whether document events should be tracked. */
    protected boolean trackDocumentEvents = false;
    /** Whether element events should be tracked. */
    protected boolean trackElementEvents = false;
    /** Whether character events should be tracked. */
    protected boolean trackCharactersEvents = false;
    /** Whether prefix mapping events should be tracked. */
    protected boolean trackPrefixMappingEvents = false;
    /** Whether comment events should be tracked. */
    protected boolean trackCommentEvents = false;
  
    /**
     * @return The recorded list of SAX events.
     */
    public List<SaxEvent> getEventList() { return eventList; }
    
    /** 
     * Set whether document SAX events should be tracked.
     */
    public void setTrackDocumentEvents( boolean trackDocumentEvents ) { this.trackDocumentEvents = trackDocumentEvents; }
    
    /**
     * Set whether element SAX events should be tracked.
     */
    public void setTrackElementEvents( boolean trackElementEvents ) { this.trackElementEvents = trackElementEvents; }
    
    /**
     * Set whether character SAX events should be tracked.
     */
    public void setTrackCharactersEvents( boolean trackCharactersEvents ) { this.trackCharactersEvents = trackCharactersEvents; }
    
    /**
     * Set whether prefix mapping events should be tracked.
     */
    public void setTrackPrefixMappingEvents( boolean trackPrefixMappingEvents ) { this.trackPrefixMappingEvents = trackPrefixMappingEvents; }
  
    public void setTrackCommentEvents( boolean trackCommentEvents ) { this.trackCommentEvents = trackCommentEvents; }
  
    public void startDocument()
    {
      if( trackDocumentEvents ) {
        SaxEvent saxEvent = new SaxEvent();
        saxEvent.setType(EventType.START_DOCUMENT);
        eventList.add(saxEvent);
      }
    }
  
    public void endDocument()
    {
      if( trackDocumentEvents ) {
        SaxEvent saxEvent = new SaxEvent();
        saxEvent.setType(EventType.END_DOCUMENT);
        eventList.add(saxEvent);
      }
    }
  
    public void startElement( String uri, String localName, String qName, Attributes attributes )
   {
     if( trackElementEvents ) {
       SaxEvent saxEvent = new SaxEvent();
       saxEvent.setType(EventType.START_ELEMENT);
       saxEvent.setUri(uri);
       saxEvent.setLocalName(localName);
       saxEvent.setQName(qName);
       saxEvent.setAttributes(new AttributesImpl(attributes));
       eventList.add(saxEvent);
     }
   }
 
   public void endElement( String uri, String localName, String qName )
   {
     if( trackElementEvents ) {
       SaxEvent saxEvent = new SaxEvent();
       saxEvent.setType(EventType.END_ELEMENT);
       saxEvent.setUri(uri);
       saxEvent.setLocalName(localName);
       eventList.add(saxEvent);
     }
   }
 
   public void characters( char[] characters, int start, int length )
   {
     if( trackCharactersEvents ) {
       // if the previous event was characters, then append.
       if( !eventList.isEmpty() && eventList.get(eventList.size()-1).getType() == EventType.CHARACTERS ) {
         SaxEvent saxEvent = eventList.get(eventList.size()-1);
         saxEvent.setText(new StringBuilder().append(saxEvent.getText()).append( characters, start, length ).toString());
       }
       else {
         SaxEvent saxEvent = new SaxEvent();
         saxEvent.setType(EventType.CHARACTERS);
         saxEvent.setText(new StringBuilder().append( characters, start, length ).toString());
         eventList.add(saxEvent);
       }
     }
   }
 
   public void startPrefixMapping( String prefix, String uri )
   {
     if( trackPrefixMappingEvents ) {
       if( !eventList.isEmpty() && eventList.get(eventList.size()-1).getType() == EventType.START_PREFIX_MAPPING ) {
         eventList.get(eventList.size()-1).getPrefixMapping().put(prefix, uri);
       }
       else {
         SaxEvent saxEvent = new SaxEvent();
         saxEvent.setType(EventType.START_PREFIX_MAPPING);
         HashMap<String, String> prefixMapping = new HashMap<String, String>();
         prefixMapping.put(prefix, uri);
         saxEvent.setPrefixMapping(prefixMapping);
         eventList.add(saxEvent);
       }
     }
   }
 
   public void endPrefixMapping( String prefix )
   {
     if( trackPrefixMappingEvents ) {
       if( !eventList.isEmpty() && eventList.get(eventList.size()-1).getType() == EventType.END_PREFIX_MAPPING ) {
         eventList.get(eventList.size()-1).getPrefixSet().add(prefix);
       }
       else {
         SaxEvent saxEvent = new SaxEvent();
         saxEvent.setType(EventType.END_PREFIX_MAPPING);
         Set<String> prefixSet = new HashSet<String>();
         prefixSet.add(prefix);
         saxEvent.setPrefixSet(prefixSet);
         eventList.add(saxEvent);
       }
     }
   }
 
   public void comment( char[] comment, int start, int length )
   {
     if( trackCommentEvents ) {
       SaxEvent saxEvent = new SaxEvent();
       saxEvent.setType(EventType.COMMENT);
       saxEvent.setText(new StringBuilder().append( comment, start, length ).toString());
       eventList.add(saxEvent);
     }
   }
   public void startDTD( String name, String publicId, String systemId ) { }
   public void endDTD() { }
   public void startCDATA() { }
   public void endCDATA() { }
   public void startEntity( String name ) { } 
   public void endEntity( String name ) { }
 
   public String toString()
   {
     StringBuilder sb = new StringBuilder();
     for( SaxEvent event : eventList ) {
       sb.append(event.toString()).append("\n");
     }
     return sb.toString();
   }
 
   public static enum EventType
   {
     START_DOCUMENT,
     END_DOCUMENT,
     START_PREFIX_MAPPING,
     END_PREFIX_MAPPING,
     START_ELEMENT,
     END_ELEMENT,
     CHARACTERS,
     COMMENT
   }
 
   /**
    * This class represents a recorded SAX event.
    */
   public static class SaxEvent
   {
     private EventType type;
     private String text;
     private String uri;
     private String localName;
     private String qName;
     private Attributes attributes;
     private Map<String, String> prefixMapping;
     private Set<String> prefixSet;
 
     public EventType getType() { return this.type; }
     public void setType( EventType type ) { this.type = type; }
     public String getText() { return this.text; }
     public void setText( String text ) { this.text = text; }
     public String getUri() { return uri; }
     public void setUri( String uri ) { this.uri = uri; }
     public String getLocalName() { return localName; }
     public void setLocalName( String localName ) { this.localName = localName; }
     public String getQName() { return qName; }
     public void setQName( String qName ) { this.qName = qName; }
     public Map<String, String> getPrefixMapping() { return this.prefixMapping; }
     public void setPrefixMapping( Map<String, String> prefixMapping ) { this.prefixMapping = prefixMapping; }
     public Set<String> getPrefixSet() { return this.prefixSet; }
     public void setPrefixSet( Set<String> prefixSet ) { this.prefixSet = prefixSet; }
     public Attributes getAttributes() { return this.attributes; }
     public void setAttributes( Attributes attributes ) { this.attributes = attributes; }
     public String toString() {
       StringBuilder sb = new StringBuilder();
       sb.append("  ").append(type).append("\n");
       if( uri != null ) {
         sb.append("  ").append("uri:").append(uri).append("\n");
       }
       if( localName != null ) {
         sb.append("  ").append("localName:").append(localName).append("\n");
       }
       if( prefixMapping != null ) {
         for( Map.Entry<String, String> entry : prefixMapping.entrySet() ) {
           sb.append("  ").append("prefix:").append(entry.getKey()).append(" namespace:").append(entry.getValue()).append("\n");
         }
       }
       return sb.toString();
     }
   }
 
 }