/*
 * 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>
 * &lt;Resource name="mail/send" auth="CONTAINER"
 *           type="javax.mail.internet.MimePartDataSource"/&gt;
 * &lt;ResourceParams name="mail/send"&gt;
 *   &lt;parameter&gt;&lt;name&gt;factory&lt;/name&gt;
 *     &lt;value&gt;org.apache.naming.factory.SendMailFactory&lt;/value&gt;
 *   &lt;/parameter&gt;
 *   &lt;parameter&gt;&lt;name&gt;mail.smtp.host&lt;/name&gt;
 *     &lt;value&gt;your.smtp.host&lt;/value&gt;
 *   &lt;/parameter&gt;
 *   &lt;parameter&gt;&lt;name&gt;mail.smtp.user&lt;/name&gt;
 *     &lt;value&gt;someuser&lt;/value&gt;
 *   &lt;/parameter&gt;
 *   &lt;parameter&gt;&lt;name&gt;mail.from&lt;/name&gt;
 *     &lt;value&gt;someuser@some.host&lt;/value&gt;
 *   &lt;/parameter&gt;
 *   &lt;parameter&gt;&lt;name&gt;mail.smtp.sendpartial&lt;/name&gt;
 *     &lt;value&gt;true&lt;/value&gt;
 *   &lt;/parameter&gt;
 *  &lt;parameter&gt;&lt;name&gt;mail.smtp.dsn.notify&lt;/name&gt;
 *     &lt;value&gt;FAILURE&lt;/value&gt;
 *   &lt;/parameter&gt;
 *   &lt;parameter&gt;&lt;name&gt;mail.smtp.dsn.ret&lt;/name&gt;
 *     &lt;value&gt;FULL&lt;/value&gt;
 *   &lt;/parameter&gt;
 * &lt;/ResourceParams&gt;
 * </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(
                    (PrivilegedAction<MimePartDataSource>) () -> {
                        // 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;
        }
    }
}
