/*
    * 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.net;
  
  import org.apache.log4j.AppenderSkeleton;
  import org.apache.log4j.Layout;
  import org.apache.log4j.Level;
  import org.apache.log4j.helpers.CyclicBuffer;
  import org.apache.log4j.helpers.LogLog;
  import org.apache.log4j.helpers.OptionConverter;
  import org.apache.log4j.spi.ErrorCode;
  import org.apache.log4j.spi.LoggingEvent;
  import org.apache.log4j.spi.OptionHandler;
  import org.apache.log4j.spi.TriggeringEventEvaluator;
  import org.apache.log4j.xml.UnrecognizedElementHandler;
  import org.w3c.dom.Element;
  
  import javax.mail.Authenticator;
  import javax.mail.Message;
  import javax.mail.MessagingException;
  import javax.mail.Multipart;
  import javax.mail.PasswordAuthentication;
  import javax.mail.Session;
  import javax.mail.Transport;
  import javax.mail.internet.AddressException;
  import javax.mail.internet.InternetAddress;
  import javax.mail.internet.InternetHeaders;
  import javax.mail.internet.MimeBodyPart;
  import javax.mail.internet.MimeMessage;
  import javax.mail.internet.MimeMultipart;
  import javax.mail.internet.MimeUtility;
  import java.io.ByteArrayOutputStream;
  import java.io.OutputStreamWriter;
  import java.io.UnsupportedEncodingException;
  import java.io.Writer;
  import java.util.Date;
  import java.util.Properties;
  
  /**
     Send an e-mail when a specific logging event occurs, typically on
     errors or fatal errors.
  
     <p>The number of logging events delivered in this e-mail depend on
     the value of <b>BufferSize</b> option. The
     <code>SMTPAppender</code> keeps only the last
     <code>BufferSize</code> logging events in its cyclic buffer. This
     keeps memory requirements at a reasonable level while still
     delivering useful application context.
  
     By default, an email message will be sent when an ERROR or higher
     severity message is appended.  The triggering criteria can be
     modified by setting the evaluatorClass property with the name
     of a class implementing TriggeringEventEvaluator, setting the evaluator
     property with an instance of TriggeringEventEvaluator or
     nesting a triggeringPolicy element where the specified
     class implements TriggeringEventEvaluator.
     
     This class has implemented UnrecognizedElementHandler since 1.2.15.
  
     Since 1.2.16, SMTP over SSL is supported by setting SMTPProtocol to "smpts".
  
     @author Ceki G&uuml;lc&uuml;
     @since 1.0 */
  public class SMTPAppender extends AppenderSkeleton
          implements UnrecognizedElementHandler {
    private String to;
    /**
     * Comma separated list of cc recipients.
     */
    private String cc;  
    /**
     * Comma separated list of bcc recipients.
     */
    private String bcc;  
    private String from;
    /**
     * Comma separated list of replyTo addresses.
     */
    private String replyTo;
    private String subject;
    private String smtpHost;
    private String smtpUsername;
    private String smtpPassword;
    private String smtpProtocol;
   private int smtpPort = -1;
   private boolean smtpDebug = false;
   private int bufferSize = 512;
   private boolean locationInfo = false;
   private boolean sendOnClose = false;
 
   protected CyclicBuffer cb = new CyclicBuffer(bufferSize);
   protected Message msg;
 
   protected TriggeringEventEvaluator evaluator;
 
 
 
   /**
      The default constructor will instantiate the appender with a
      {@link TriggeringEventEvaluator} that will trigger on events with
      level ERROR or higher.*/
   public
   SMTPAppender() {
     this(new DefaultEvaluator());
   }
 
 
   /**
      Use <code>evaluator</code> passed as parameter as the {@link
      TriggeringEventEvaluator} for this SMTPAppender.  */
   public
   SMTPAppender(TriggeringEventEvaluator evaluator) {
     this.evaluator = evaluator;
   }
 
 
   /**
      Activate the specified options, such as the smtp host, the
      recipient, from, etc. */
   public
   void activateOptions() {
     Session session = createSession();
     msg = new MimeMessage(session);
 
      try {
         addressMessage(msg);
         if(subject != null) {
            try {
                 msg.setSubject(MimeUtility.encodeText(subject, "UTF-8", null));
            } catch(UnsupportedEncodingException ex) {
                 LogLog.error("Unable to encode SMTP subject", ex);
            }
         }
      } catch(MessagingException e) {
        LogLog.error("Could not activate SMTPAppender options.", e );
      }
 
      if (evaluator instanceof OptionHandler) {
          ((OptionHandler) evaluator).activateOptions();
      }
   }
   
   /**
    *   Address message.
    *   @param msg message, may not be null.
    *   @throws MessagingException thrown if error addressing message. 
    *   @since 1.2.14
    */
   protected void addressMessage(final Message msg) throws MessagingException {
        if (from != null) {
 	 		msg.setFrom(getAddress(from));
        } else {
 	 		msg.setFrom();
 	   }
 
       //Add ReplyTo addresses if defined.
          if (replyTo != null && replyTo.length() > 0) {
                msg.setReplyTo(parseAddress(replyTo));
          }
 
        if (to != null && to.length() > 0) {
              msg.setRecipients(Message.RecipientType.TO, parseAddress(to));
        }
 
       //Add CC receipients if defined.
 	  if (cc != null && cc.length() > 0) {
 		msg.setRecipients(Message.RecipientType.CC, parseAddress(cc));
 	  }
 
       //Add BCC receipients if defined.
 	  if (bcc != null && bcc.length() > 0) {
 		msg.setRecipients(Message.RecipientType.BCC, parseAddress(bcc));
 	  }
   }
   
   /**
    *  Create mail session.
    *  @return mail session, may not be null.
    *  @since 1.2.14
    */
   protected Session createSession() {
     Properties props = null;
     try {
         props = new Properties (System.getProperties());
     } catch(SecurityException ex) {
         props = new Properties();
     }
 
     String prefix = "mail.smtp";
     if (smtpProtocol != null) {
         props.put("mail.transport.protocol", smtpProtocol);
         prefix = "mail." + smtpProtocol;
     }
     if (smtpHost != null) {
       props.put(prefix + ".host", smtpHost);
     }
     if (smtpPort > 0) {
         props.put(prefix + ".port", String.valueOf(smtpPort));
     }
     
     Authenticator auth = null;
     if(smtpPassword != null && smtpUsername != null) {
       props.put(prefix + ".auth", "true");
       auth = new Authenticator() {
         protected PasswordAuthentication getPasswordAuthentication() {
           return new PasswordAuthentication(smtpUsername, smtpPassword);
         }
       };
     }
     Session session = Session.getInstance(props, auth);
     if (smtpProtocol != null) {
         session.setProtocolForAddress("rfc822", smtpProtocol);
     }
     if (smtpDebug) {
         session.setDebug(smtpDebug);
     }
     return session;
   }
 
   /**
      Perform SMTPAppender specific appending actions, mainly adding
      the event to a cyclic buffer and checking if the event triggers
      an e-mail to be sent. */
   public
   void append(LoggingEvent event) {
 
     if(!checkEntryConditions()) {
       return;
     }
 
     event.getThreadName();
     event.getNDC();
     event.getMDCCopy();
     if(locationInfo) {
       event.getLocationInformation();
     }
     event.getRenderedMessage();
     event.getThrowableStrRep();
     cb.add(event);
     if(evaluator.isTriggeringEvent(event)) {
       sendBuffer();
     }
   }
 
  /**
      This method determines if there is a sense in attempting to append.
 
      <p>It checks whether there is a set output target and also if
      there is a set layout. If these checks fail, then the boolean
      value <code>false</code> is returned. */
   protected
   boolean checkEntryConditions() {
     if(this.msg == null) {
       errorHandler.error("Message object not configured.");
       return false;
     }
 
     if(this.evaluator == null) {
       errorHandler.error("No TriggeringEventEvaluator is set for appender ["+
 			 name+"].");
       return false;
     }
 
 
     if(this.layout == null) {
       errorHandler.error("No layout set for appender named ["+name+"].");
       return false;
     }
     return true;
   }
 
 
   synchronized
   public
   void close() {
     this.closed = true;
     if (sendOnClose && cb.length() > 0) {
         sendBuffer();
     }
   }
 
   InternetAddress getAddress(String addressStr) {
     try {
       return new InternetAddress(addressStr);
     } catch(AddressException e) {
       errorHandler.error("Could not parse address ["+addressStr+"].", e,
 			 ErrorCode.ADDRESS_PARSE_FAILURE);
       return null;
     }
   }
 
   InternetAddress[] parseAddress(String addressStr) {
     try {
       return InternetAddress.parse(addressStr, true);
     } catch(AddressException e) {
       errorHandler.error("Could not parse address ["+addressStr+"].", e,
 			 ErrorCode.ADDRESS_PARSE_FAILURE);
       return null;
     }
   }
 
   /**
      Returns value of the <b>To</b> option.
    */
   public
   String getTo() {
     return to;
   }
 
 
   /**
      The <code>SMTPAppender</code> requires a {@link
      org.apache.log4j.Layout layout}.  */
   public
   boolean requiresLayout() {
     return true;
   }
 
   /**
    * Layout body of email message.
    * @since 1.2.16  
    */
   protected String formatBody() {
 	  
 	  // Note: this code already owns the monitor for this
 	  // appender. This frees us from needing to synchronize on 'cb'.
 	  
       StringBuffer sbuf = new StringBuffer();
       String t = layout.getHeader();
       if(t != null)
 	sbuf.append(t);
       int len =  cb.length();
       for(int i = 0; i < len; i++) {
 	//sbuf.append(MimeUtility.encodeText(layout.format(cb.get())));
 	LoggingEvent event = cb.get();
 	sbuf.append(layout.format(event));
 	if(layout.ignoresThrowable()) {
 	  String[] s = event.getThrowableStrRep();
 	  if (s != null) {
 	    for(int j = 0; j < s.length; j++) {
 	      sbuf.append(s[j]);
 	      sbuf.append(Layout.LINE_SEP);
 	    }
 	  }
 	}
       }
       t = layout.getFooter();
       if(t != null) {
 	    sbuf.append(t);
       }
       
       return sbuf.toString();
   }
   
   /**
      Send the contents of the cyclic buffer as an e-mail message.
    */
   protected
   void sendBuffer() {
 
     try {
       String s = formatBody();
       boolean allAscii = true;
       for(int i = 0; i < s.length() && allAscii; i++) {
           allAscii = s.charAt(i) <= 0x7F;
       }
       MimeBodyPart part;
       if (allAscii) {
           part = new MimeBodyPart();
           part.setContent(s, layout.getContentType());
       } else {
           try {
             ByteArrayOutputStream os = new ByteArrayOutputStream();
             Writer writer = new OutputStreamWriter(
                     MimeUtility.encode(os, "quoted-printable"), "UTF-8");
             writer.write(s);
             writer.close();
             InternetHeaders headers = new InternetHeaders();
             headers.setHeader("Content-Type", layout.getContentType() + "; charset=UTF-8");
             headers.setHeader("Content-Transfer-Encoding", "quoted-printable");
             part = new MimeBodyPart(headers, os.toByteArray());
           } catch(Exception ex) {
               StringBuffer sbuf = new StringBuffer(s);
               for (int i = 0; i < sbuf.length(); i++) {
                   if (sbuf.charAt(i) >= 0x80) {
                       sbuf.setCharAt(i, '?');
                   }
               }
               part = new MimeBodyPart();
               part.setContent(sbuf.toString(), layout.getContentType());
           }
       }
 
 
 
       Multipart mp = new MimeMultipart();
       mp.addBodyPart(part);
       msg.setContent(mp);
 
       msg.setSentDate(new Date());
       Transport.send(msg);
     } catch(MessagingException e) {
       LogLog.error("Error occured while sending e-mail notification.", e);
     } catch(RuntimeException e) {
       LogLog.error("Error occured while sending e-mail notification.", e);
     }
   }
 
 
 
   /**
      Returns value of the <b>EvaluatorClass</b> option.
    */
   public
   String getEvaluatorClass() {
     return evaluator == null ? null : evaluator.getClass().getName();
   }
 
   /**
      Returns value of the <b>From</b> option.
    */
   public
   String getFrom() {
     return from;
   }
 
   /**
      Get the reply addresses.
      @return reply addresses as comma separated string, may be null.
      @since 1.2.16
    */
   public
   String getReplyTo() {
     return replyTo;
   }
 
   /**
      Returns value of the <b>Subject</b> option.
    */
   public
   String getSubject() {
     return subject;
   }
 
   /**
      The <b>From</b> option takes a string value which should be a
      e-mail address of the sender.
    */
   public
   void setFrom(String from) {
     this.from = from;
   }
 
   /**
      Set the e-mail addresses to which replies should be directed.
      @param addresses reply addresses as comma separated string, may be null.
      @since 1.2.16
    */
   public
   void setReplyTo(final String addresses) {
     this.replyTo = addresses;
   }
 
 
   /**
      The <b>Subject</b> option takes a string value which should be a
      the subject of the e-mail message.
    */
   public
   void setSubject(String subject) {
     this.subject = subject;
   }
 
 
   /**
      The <b>BufferSize</b> option takes a positive integer
      representing the maximum number of logging events to collect in a
      cyclic buffer. When the <code>BufferSize</code> is reached,
      oldest events are deleted as new events are added to the
      buffer. By default the size of the cyclic buffer is 512 events.
    */
   public
   void setBufferSize(int bufferSize) {
     this.bufferSize = bufferSize;
     cb.resize(bufferSize);
   }
 
   /**
      The <b>SMTPHost</b> option takes a string value which should be a
      the host name of the SMTP server that will send the e-mail message.
    */
   public
   void setSMTPHost(String smtpHost) {
     this.smtpHost = smtpHost;
   }
 
   /**
      Returns value of the <b>SMTPHost</b> option.
    */
   public
   String getSMTPHost() {
     return smtpHost;
   }
 
   /**
      The <b>To</b> option takes a string value which should be a
      comma separated list of e-mail address of the recipients.
    */
   public
   void setTo(String to) {
     this.to = to;
   }
 
 
 
   /**
      Returns value of the <b>BufferSize</b> option.
    */
   public
   int getBufferSize() {
     return bufferSize;
   }
 
   /**
      The <b>EvaluatorClass</b> option takes a string value
      representing the name of the class implementing the {@link
      TriggeringEventEvaluator} interface. A corresponding object will
      be instantiated and assigned as the triggering event evaluator
      for the SMTPAppender.
    */
   public
   void setEvaluatorClass(String value) {
       evaluator = (TriggeringEventEvaluator)
                 OptionConverter.instantiateByClassName(value,
 					   TriggeringEventEvaluator.class,
 						       evaluator);
   }
 
 
   /**
      The <b>LocationInfo</b> option takes a boolean value. By
      default, it is set to false which means there will be no effort
      to extract the location information related to the event. As a
      result, the layout that formats the events as they are sent out
      in an e-mail is likely to place the wrong location information
      (if present in the format).
 
      <p>Location information extraction is comparatively very slow and
      should be avoided unless performance is not a concern.
    */
   public
   void setLocationInfo(boolean locationInfo) {
     this.locationInfo = locationInfo;
   }
 
   /**
      Returns value of the <b>LocationInfo</b> option.
    */
   public
   boolean getLocationInfo() {
     return locationInfo;
   }
   
    /**
       Set the cc recipient addresses.
       @param addresses recipient addresses as comma separated string, may be null.
       @since 1.2.14
     */
    public void setCc(final String addresses) {
      this.cc = addresses;
    }
 
    /**
       Get the cc recipient addresses.
       @return recipient addresses as comma separated string, may be null.
       @since 1.2.14
     */
     public String getCc() {
      return cc;
     }
 
    /**
       Set the bcc recipient addresses.
       @param addresses recipient addresses as comma separated string, may be null.
       @since 1.2.14
     */
    public void setBcc(final String addresses) {
      this.bcc = addresses;
    }
 
    /**
       Get the bcc recipient addresses.
       @return recipient addresses as comma separated string, may be null.
       @since 1.2.14
     */
     public String getBcc() {
      return bcc;
     }
 
   /**
    * The <b>SmtpPassword</b> option takes a string value which should be the password required to authenticate against
    * the mail server.
    * @param password password, may be null.
    * @since 1.2.14
    */
   public void setSMTPPassword(final String password) {
     this.smtpPassword = password;
   }
  
   /**
    * The <b>SmtpUsername</b> option takes a string value which should be the username required to authenticate against
    * the mail server.
    * @param username user name, may be null.
    * @since 1.2.14
    */
   public void setSMTPUsername(final String username) {
     this.smtpUsername = username;
   }
 
   /**
    * Setting the <b>SmtpDebug</b> option to true will cause the mail session to log its server interaction to stdout.
    * This can be useful when debuging the appender but should not be used during production because username and
    * password information is included in the output.
    * @param debug debug flag.
    * @since 1.2.14
    */
   public void setSMTPDebug(final boolean debug) {
     this.smtpDebug = debug;
   }
   
   /**
    * Get SMTP password.
    * @return SMTP password, may be null.
    * @since 1.2.14
    */
   public String getSMTPPassword() {
     return smtpPassword;
   }
  
   /**
    * Get SMTP user name.
    * @return SMTP user name, may be null.
    * @since 1.2.14
    */
   public String getSMTPUsername() {
     return smtpUsername;
   }
 
   /**
    * Get SMTP debug.
    * @return SMTP debug flag.
    * @since 1.2.14
    */
   public boolean getSMTPDebug() {
     return smtpDebug;
   }
 
     /**
      * Sets triggering evaluator.
      * @param trigger triggering event evaluator.
      * @since 1.2.15
      */
   public final void setEvaluator(final TriggeringEventEvaluator trigger) {
       if (trigger == null) {
           throw new NullPointerException("trigger");
       }
       this.evaluator = trigger;
   }
 
     /**
      * Get triggering evaluator.
      * @return triggering event evaluator.
      * @since 1.2.15
      */
   public final TriggeringEventEvaluator getEvaluator() {
       return evaluator;
   }
 
   /** {@inheritDoc}
    * @since 1.2.15 
   */
   public boolean parseUnrecognizedElement(final Element element,
                                           final Properties props) throws Exception {
       if ("triggeringPolicy".equals(element.getNodeName())) {
           Object triggerPolicy =
                   org.apache.log4j.xml.DOMConfigurator.parseElement(
                           element, props, TriggeringEventEvaluator.class);
           if (triggerPolicy instanceof TriggeringEventEvaluator) {
               setEvaluator((TriggeringEventEvaluator) triggerPolicy);
           }
           return true;
       }
 
       return false;
   }
 
     /**
      * Get transport protocol.
      * Typically null or "smtps".
      *
      * @return transport protocol, may be null.
      * @since 1.2.16
      */
   public final String getSMTPProtocol() {
       return smtpProtocol;
   }
 
     /**
      * Set transport protocol.
      * Typically null or "smtps".
      *
      * @param val transport protocol, may be null.
      * @since 1.2.16
      */
   public final void setSMTPProtocol(final String val) {
       smtpProtocol = val;
   }
 
     /**
      * Get port.
      *
      * @return port, negative values indicate use of default ports for protocol.
      * @since 1.2.16
      */
   public final int getSMTPPort() {
         return smtpPort;
   }
 
     /**
      * Set port.
      *
      * @param val port, negative values indicate use of default ports for protocol.
      * @since 1.2.16
      */
   public final void setSMTPPort(final int val) {
         smtpPort = val;
   }
 
     /**
      * Get sendOnClose.
      *
      * @return if true all buffered logging events will be sent when the appender is closed.
      * @since 1.2.16
      */
   public final boolean getSendOnClose() {
         return sendOnClose;
   }
 
     /**
      * Set sendOnClose.
      *
      * @param val if true all buffered logging events will be sent when appender is closed.
      * @since 1.2.16
      */
   public final void setSendOnClose(final boolean val) {
         sendOnClose = val;
   }
 
 }
 
 class DefaultEvaluator implements TriggeringEventEvaluator {
   /**
      Is this <code>event</code> the e-mail triggering event?
 
      <p>This method returns <code>true</code>, if the event level
      has ERROR level or higher. Otherwise it returns
      <code>false</code>. */
   public
   boolean isTriggeringEvent(LoggingEvent event) {
     return event.getLevel().isGreaterOrEqual(Level.ERROR);
   }
 }