/*
 * 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.naming.factory;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;

import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimePartDataSource;
import javax.naming.Context;
import javax.naming.Name;
import javax.naming.RefAddr;
import javax.naming.Reference;
import javax.naming.spi.ObjectFactory;

/**
 * Factory class that creates a JNDI named javamail MimePartDataSource
 * object which can be used for sending email using SMTP.
 * <p>
 * Can be configured in the Context scope
 * of your server.xml configuration file.
 * <p>
 * Example:
 * <pre>
 * <Resource name="mail/send" auth="CONTAINER"
 *           type="javax.mail.internet.MimePartDataSource"/>
 * <ResourceParams name="mail/send">
 *   <parameter><name>factory</name>
 *     <value>org.apache.naming.factory.SendMailFactory</value>
 *   </parameter>
 *   <parameter><name>mail.smtp.host</name>
 *     <value>your.smtp.host</value>
 *   </parameter>
 *   <parameter><name>mail.smtp.user</name>
 *     <value>someuser</value>
 *   </parameter>
 *   <parameter><name>mail.from</name>
 *     <value>someuser@some.host</value>
 *   </parameter>
 *   <parameter><name>mail.smtp.sendpartial</name>
 *     <value>true</value>
 *   </parameter>
 *  <parameter><name>mail.smtp.dsn.notify</name>
 *     <value>FAILURE</value>
 *   </parameter>
 *   <parameter><name>mail.smtp.dsn.ret</name>
 *     <value>FULL</value>
 *   </parameter>
 * </ResourceParams>
 * </pre>
 *
 * @author Glenn Nielsen Rich Catlett
 */

public class SendMailFactory implements ObjectFactory
{
    // The class name for the javamail MimeMessageDataSource
    protected static final String DataSourceClassName =
        "javax.mail.internet.MimePartDataSource";

    @Override
    public Object getObjectInstance(Object refObj, Name name, Context ctx,
            Hashtable<?,?> env) throws Exception {
        final Reference ref = (Reference)refObj;

        // Creation of the DataSource is wrapped inside a doPrivileged
        // so that javamail can read its default properties without
        // throwing Security Exceptions
        if (ref.getClassName().equals(DataSourceClassName)) {
            return AccessController.doPrivileged(
                    new PrivilegedAction<MimePartDataSource>()
            {
                @Override
                public MimePartDataSource run() {
                    // set up the smtp session that will send the message
                    Properties props = new Properties();
                    // enumeration of all refaddr
                    Enumeration<RefAddr> list = ref.getAll();
                    // current refaddr to be set
                    RefAddr refaddr;
                    // set transport to smtp
                    props.put("mail.transport.protocol", "smtp");

                    while (list.hasMoreElements()) {
                        refaddr = list.nextElement();

                        // set property
                        props.put(refaddr.getType(), refaddr.getContent());
                    }
                    MimeMessage message = new MimeMessage(
                        Session.getInstance(props));
                    try {
                        RefAddr fromAddr = ref.get("mail.from");
                        String from = null;
                        if (fromAddr != null) {
                            from = (String)ref.get("mail.from").getContent();
                        }
                        if (from != null) {
                            message.setFrom(new InternetAddress(from));
                        }
                        message.setSubject("");
                    } catch (Exception e) {/*Ignore*/}
                    MimePartDataSource mds = new MimePartDataSource(message);
                    return mds;
                }
            } );
        }
        else { // We can't create an instance of the DataSource
            return null;
        }
    }
}