/*
    * 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.
   */
  
  package org.apache.log4j.xml;
  
  import java.awt.Component;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.LineNumberReader;
  import java.io.StringReader;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.Hashtable;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.Vector;
  import java.util.zip.ZipInputStream;
  
  import javax.swing.ProgressMonitorInputStream;
  import javax.xml.parsers.DocumentBuilder;
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.parsers.ParserConfigurationException;
  
  import org.apache.log4j.Level;
  import org.apache.log4j.Logger;
  import org.apache.log4j.helpers.UtilLoggingLevel;
  import org.apache.log4j.spi.Decoder;
  import org.apache.log4j.spi.LoggingEvent;
  import org.apache.log4j.spi.ThrowableInformation;
  import org.apache.log4j.spi.LocationInfo;
  import org.w3c.dom.Document;
  import org.w3c.dom.Node;
  import org.w3c.dom.NodeList;
  import org.xml.sax.InputSource;
  
  
  /**
   * Decodes JDK 1.4's java.util.logging package events
   * delivered via XML (using the logger.dtd).
   *
   * @author Scott Deboy (sdeboy@apache.org)
   * @author Paul Smith (psmith@apache.org)
   *
   */
  public class UtilLoggingXMLDecoder implements Decoder {
    //NOTE: xml section is only handed on first delivery of events
    //on this first delivery of events, there is no end tag for the log element
    /**
     * Document prolog.
     */
    private static final String BEGIN_PART =
      "<log>";
      /**
       * Document close.
       */
    private static final String END_PART = "</log>";
      /**
       * Document builder.
       */
    private DocumentBuilder docBuilder;
      /**
       * Additional properties.
       */
    private Map additionalProperties = new HashMap();
      /**
       * Partial event.
       */
    private String partialEvent;
      /**
       * Record end.
       */
    private static final String RECORD_END = "</record>";
      /**
       * Owner.
       */
    private Component owner = null;
  
    private static final String ENCODING = "UTF-8";
  
      /**
       * Create new instance.
       * @param o owner
       */
   public UtilLoggingXMLDecoder(final Component o) {
       this();
       this.owner = o;
   }
 
     /**
      * Create new instance.
      */
   public UtilLoggingXMLDecoder() {
     DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
     dbf.setValidating(false);
 
     try {
       docBuilder = dbf.newDocumentBuilder();
       docBuilder.setErrorHandler(new SAXErrorHandler());
       docBuilder.setEntityResolver(new UtilLoggingEntityResolver());
     } catch (ParserConfigurationException pce) {
       System.err.println("Unable to get document builder");
     }
   }
 
   /**
    * Sets an additionalProperty map, where each Key/Value pair is
    * automatically added to each LoggingEvent as it is decoded.
    *
    * This is useful, say, to include the source file name of the Logging events
    * @param properties additional properties
    */
   public void setAdditionalProperties(final Map properties) {
     this.additionalProperties = properties;
   }
 
   /**
    * Converts the LoggingEvent data in XML string format into an actual
    * XML Document class instance.
    * @param data XML fragment
    * @return  dom document
    */
   private Document parse(final String data) {
     if (docBuilder == null || data == null) {
       return null;
     }
 
     Document document = null;
 
     try {
       // we change the system ID to a valid URI so that Crimson won't
       // complain. Indeed, "log4j.dtd" alone is not a valid URI which
       // causes Crimson to barf. The Log4jEntityResolver only cares
       // about the "log4j.dtd" ending.
 
       /**
        * resetting the length of the StringBuffer is dangerous, particularly
        * on some JDK 1.4 impls, there's a known Bug that causes a memory leak
        */
       StringBuffer buf = new StringBuffer(1024);
 
       if (!data.startsWith("<?xml")) {
         buf.append(BEGIN_PART);
       }
 
       buf.append(data);
 
       if (!data.endsWith(END_PART)) {
         buf.append(END_PART);
       }
 
       InputSource inputSource =
         new InputSource(new StringReader(buf.toString()));
       document = docBuilder.parse(inputSource);
     } catch (Exception e) {
       e.printStackTrace();
     }
 
     return document;
   }
 
   /**
    * Decodes a File into a Vector of LoggingEvents.
    * @param url the url of a file containing events to decode
    * @return Vector of LoggingEvents
    * @throws IOException if IO error during processing.
    */
   public Vector decode(final URL url) throws IOException {
     LineNumberReader reader;
     boolean isZipFile = url.getPath().toLowerCase().endsWith(".zip");
     InputStream inputStream;
     if (isZipFile) {
         inputStream = new ZipInputStream(url.openStream());
         //move stream to next entry so we can read it
         ((ZipInputStream)inputStream).getNextEntry();
     } else {
         inputStream = url.openStream();
     }
     if (owner != null) {
         reader = new LineNumberReader(
                 new InputStreamReader(
                         new ProgressMonitorInputStream(owner,
                                 "Loading " + url , inputStream), ENCODING));
     } else {
         reader = new LineNumberReader(new InputStreamReader(inputStream, ENCODING));
     }
     Vector v = new Vector();
 
       String line;
       Vector events;
       try {
           while ((line = reader.readLine()) != null) {
               StringBuffer buffer = new StringBuffer(line);
               for (int i = 0; i < 1000; i++) {
                   buffer.append(reader.readLine()).append("\n");
               }
               events = decodeEvents(buffer.toString());
               if (events != null) {
                   v.addAll(events);
               }
           }
     } finally {
       partialEvent = null;
       try {
         if (reader != null) {
           reader.close();
         }
       } catch (Exception e) {
         e.printStackTrace();
       }
     }
     return v;
   }
 
   /**
    * Decodes a String representing a number of events into a
    * Vector of LoggingEvents.
    * @param document to decode events from
    * @return Vector of LoggingEvents
    */
   public Vector decodeEvents(final String document) {
 
       if (document != null) {
 
           if (document.trim().equals("")) {
               return null;
           }
 
           String newDoc;
           String newPartialEvent = null;
           //separate the string into the last portion ending with </record>
           // (which will be processed) and the partial event which
           // will be combined and processed in the next section
 
           //if the document does not contain a record end,
           // append it to the partial event string
           if (document.lastIndexOf(RECORD_END) == -1) {
               partialEvent = partialEvent + document;
               return null;
           }
 
           if (document.lastIndexOf(RECORD_END) + RECORD_END.length()
                   < document.length()) {
               newDoc = document.substring(0,
                       document.lastIndexOf(RECORD_END) + RECORD_END.length());
               newPartialEvent = document.substring(
                       document.lastIndexOf(RECORD_END) + RECORD_END.length());
           } else {
               newDoc = document;
           }
           if (partialEvent != null) {
               newDoc = partialEvent + newDoc;
           }
           partialEvent = newPartialEvent;
 
           Document doc = parse(newDoc);
           if (doc == null) {
               return null;
           }
           return decodeEvents(doc);
       }
       return null;
   }
 
     /**
       * Converts the string data into an XML Document, and then soaks out the
       * relevant bits to form a new LoggingEvent instance which can be used
       * by any Log4j element locally.
       * @param data XML fragment
       * @return a single LoggingEvent or null
       */
   public LoggingEvent decode(final String data) {
     Document document = parse(data);
 
     if (document == null) {
       return null;
     }
 
     Vector events = decodeEvents(document);
 
     if (events.size() > 0) {
       return (LoggingEvent) events.firstElement();
     }
 
     return null;
   }
 
   /**
    * Given a Document, converts the XML into a Vector of LoggingEvents.
    * @param document XML document
    * @return Vector of LoggingEvents
    */
   private Vector decodeEvents(final Document document) {
     Vector events = new Vector();
 
     NodeList eventList = document.getElementsByTagName("record");
 
     for (int eventIndex = 0; eventIndex < eventList.getLength();
         eventIndex++) {
       Node eventNode = eventList.item(eventIndex);
 
       Logger logger = null;
     long timeStamp = 0L;
     Level level = null;
     String threadName = null;
     Object message = null;
     String ndc = null;
     String[] exception = null;
     String className = null;
     String methodName = null;
     String fileName = null;
     String lineNumber = null;
     Hashtable properties = new Hashtable();
 
       //format of date: 2003-05-04T11:04:52
       //ignore date or set as a property? using millis in constructor instead
       NodeList list = eventNode.getChildNodes();
       int listLength = list.getLength();
 
       if (listLength == 0) {
         continue;
       }
 
       for (int y = 0; y < listLength; y++) {
         String tagName = list.item(y).getNodeName();
 
         if (tagName.equalsIgnoreCase("logger")) {
           logger = Logger.getLogger(getCData(list.item(y)));
         }
 
         if (tagName.equalsIgnoreCase("millis")) {
           timeStamp = Long.parseLong(getCData(list.item(y)));
         }
 
         if (tagName.equalsIgnoreCase("level")) {
           level = UtilLoggingLevel.toLevel(getCData(list.item(y)));
         }
 
         if (tagName.equalsIgnoreCase("thread")) {
           threadName = getCData(list.item(y));
         }
 
         if (tagName.equalsIgnoreCase("sequence")) {
           properties.put("log4jid", getCData(list.item(y)));
         }
 
         if (tagName.equalsIgnoreCase("message")) {
           message = getCData(list.item(y));
         }
 
         if (tagName.equalsIgnoreCase("class")) {
           className = getCData(list.item(y));
         }
 
         if (tagName.equalsIgnoreCase("method")) {
           methodName = getCData(list.item(y));
         }
 
         if (tagName.equalsIgnoreCase("exception")) {
           ArrayList exceptionList = new ArrayList();
           NodeList exList = list.item(y).getChildNodes();
           int exlistLength = exList.getLength();
 
           for (int i2 = 0; i2 < exlistLength; i2++) {
             Node exNode = exList.item(i2);
             String exName = exList.item(i2).getNodeName();
 
             if (exName.equalsIgnoreCase("message")) {
               exceptionList.add(getCData(exList.item(i2)));
             }
 
             if (exName.equalsIgnoreCase("frame")) {
               NodeList exList2 = exNode.getChildNodes();
               int exlist2Length = exList2.getLength();
 
               for (int i3 = 0; i3 < exlist2Length; i3++) {
                 exceptionList.add(getCData(exList2.item(i3)) + "\n");
               }
             }
           }
           if (exceptionList.size() > 0) {
               exception =
                 (String[]) exceptionList.toArray(new String[exceptionList.size()]);
           }
         }
       }
 
         /**
          * We add all the additional properties to the properties
          * hashtable. Override properties that already exist
          */
         if (additionalProperties.size() > 0) {
             if (properties == null) {
                 properties = new Hashtable(additionalProperties);
             }
             Iterator i = additionalProperties.entrySet().iterator();
             while (i.hasNext()) {
                 Map.Entry e = (Map.Entry) i.next();
                 properties.put(e.getKey(), e.getValue());
             }
         }
 
       LocationInfo info;
       if ((fileName != null)
               || (className != null)
               || (methodName != null)
               || (lineNumber != null)) {
           info = new LocationInfo(fileName, className, methodName, lineNumber);
       } else {
         info = LocationInfo.NA_LOCATION_INFO;
       }
 
         ThrowableInformation throwableInfo = null;
         if (exception != null) {
             throwableInfo = new ThrowableInformation(exception);
         }
 
         LoggingEvent loggingEvent = new LoggingEvent(null,
                 logger, timeStamp, level, message,
                 threadName,
                 throwableInfo,
                 ndc,
                 info,
                 properties);
 
       events.add(loggingEvent);
 
     }
     return events;
   }
 
     /**
      * Get contents of CDATASection.
      * @param n CDATASection
      * @return text content of all text or CDATA children of node.
      */
   private String getCData(final Node n) {
     StringBuffer buf = new StringBuffer();
     NodeList nl = n.getChildNodes();
 
     for (int x = 0; x < nl.getLength(); x++) {
       Node innerNode = nl.item(x);
 
       if (
         (innerNode.getNodeType() == Node.TEXT_NODE)
           || (innerNode.getNodeType() == Node.CDATA_SECTION_NODE)) {
         buf.append(innerNode.getNodeValue());
       }
     }
 
     return buf.toString();
   }
 }