/*

  * Copyright 2005-2007 The Kuali Foundation

  * 

  * 

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  * 

  * 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.kuali.rice.kew.mail;

 import java.util.Properties;

 import javax.activation.DataHandler;

 import javax.mail.Address;

 import javax.mail.Authenticator;

 import javax.mail.Message;

 import javax.mail.MessagingException;

 import javax.mail.NoSuchProviderException;

 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.MimeMessage;

 import org.kuali.rice.kew.util.ByteArrayDataSource;

 /**

  * Maintains a Java Mail session and can be used for sending emails.

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class Mailer {

             protected final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(getClass());

             private Properties configProperties;

             private Authenticator authenticator;

             private Session currentSession;

             /**

              * Create a AuthenticatedMailer with the default values for authenticated

              * use of mail-relay.iu.edu.

              * 

              * The Kerberos principle and and password should be a system principle

              * rather than a user principle.

              * 

              * @param senderAddress

              *            return address for the mail being sent

              * @param kbPrincipleName

              *            kerberos principle name used to authenticate to mail-relay

              * @param kbPrinciplePassword

              *            kerberos principle password used to authenticate to mail-relay

              */

             public Mailer(Properties configProperties, Authenticator authenticator) {

                     this.configProperties = configProperties;

                     this.authenticator = authenticator;

             }

             public Mailer(Properties configProperties) {

                     this(configProperties, null);

             }

             public Mailer(Properties configProperties, String username, String password) {

                     this(configProperties, new SimpleAuthenticator(username, password));

             }

             /**

              * A method to configure the Mailer properties. This class will default to a

              * set of properties but this method allows the calling program to set the

              * specific properties.

              * 

              * @param mailConfigProperties

              *            Proeprties object containing configuration information

              */

             public void setConfig(Properties configProperties) {

                 this.configProperties = configProperties;

             }

             /**

              * Sends an email to the given recipients.

              * 

              * @param recipients

              *            list of addresses to which the message is sent

              * @param subject

              *            subject of the message

              * @param messageBody

              *            body of the message

              * @param ccRecipients

              *            list of addresses which are to be cc'd on the message

              * @param bccRecipients

              *            list of addresses which are to be bcc'd on the message

              *

              * @throws AddressException

              * @throws MessagingException

              */

             public void sendMessage(String sender, Address[] recipients, String subject, String messageBody, Address[] ccRecipients, Address[] bccRecipients, boolean htmlMessage) throws AddressException, MessagingException {

                     Session session = getCurrentSession();

                     session.setDebug(LOG.isDebugEnabled());

                 Message message = new MimeMessage(session);

                 // From Address

                 message.setFrom(new InternetAddress(sender));

                 // To Address

                 if (recipients != null && recipients.length > 0) {

                     message.addRecipients(Message.RecipientType.TO, recipients);

                 } else {

                     LOG.warn("No recipients indicated");

                 }

                 // CC Address

                 if (ccRecipients != null && ccRecipients.length > 0) {

                     message.addRecipients(Message.RecipientType.CC, ccRecipients);

                 }

                 // BCC Address

                 if (bccRecipients != null && bccRecipients.length > 0) {

                     message.addRecipients(Message.RecipientType.BCC, bccRecipients);

                 }

                 // The Subject

                 message.setSubject(subject);

                 if (subject == null || "".equals(subject)) {

                     LOG.warn("Empty subject being sent");

                 }

                 // Now the message body.

                 if (htmlMessage) {

                     prepareHtmlMessage(messageBody, message);

                 } else {

                     message.setText(messageBody);

                     if (messageBody == null || "".equals(messageBody)) {

                         LOG.warn("Empty message body being sent.");

                     }

                 }

                 // Finally, send the message!

                 Transport.send(message);

             }

             /**

              * Send a message to the designated recipient with the specified subject and

              * message. This is a convience class for simple message addressing

              * 

              * @param recipient

              *            the email address to which the message is sent

              * @param subject

              *            subject for the message

              * @param messageBody

              *            body of the message to to be sent

              * @param ccRecipient

              *            email address of a cc recipient

              */

             public void sendMessage(String sender, String recipient, String subject, String messageBody, boolean htmlMessage) throws AddressException, MessagingException {

                 final Address[] NO_RECIPIENTS = null;

                 Address[] recipients = { new InternetAddress(recipient) };

                 sendMessage(sender, recipients, subject, messageBody, NO_RECIPIENTS, NO_RECIPIENTS, htmlMessage);

             }

             /**

              * @return current properties used to configure the mail session

              */

             public Properties getConfig() {

                 return configProperties;

             }

             public Authenticator getAuthenticator() {

                     return authenticator;

             }

             /**

              * This allows direct access to the Mail Session. While this offers more

              * flexibility, the AuthenticatedMailer will no longer be responsible for

              * management of the this session.

              * 

              * @return get the current session. If current session is null it creates a

              *         new one.

              */

             public Session getCurrentSession() throws NoSuchProviderException {

                 if (this.currentSession == null || !this.currentSession.getTransport().isConnected()) {

                     this.currentSession = Session.getInstance(configProperties, authenticator);

                 }

                 return currentSession;

             }

             private void prepareHtmlMessage(String messageText, Message message) throws MessagingException {

                 message.setDataHandler(new DataHandler(new ByteArrayDataSource(messageText, "text/html")));

             }

             /**

              * SimpleAuthenticator is used to do simple authentication when the SMTP

              * server requires it.

              */

             private static class SimpleAuthenticator extends javax.mail.Authenticator {

                     private final PasswordAuthentication passwordAuthentication;

                 private SimpleAuthenticator(String username, String password) {

                         this.passwordAuthentication = new PasswordAuthentication(username, password);

                 }

                 public PasswordAuthentication getPasswordAuthentication() {

                     return passwordAuthentication;

                 }

             }

 }