/*
 * 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.naming.Context;
import javax.naming.Name;
import javax.naming.RefAddr;
import javax.naming.Reference;
import javax.naming.spi.ObjectFactory;

import jakarta.mail.Authenticator;
import jakarta.mail.PasswordAuthentication;
import jakarta.mail.Session;

Factory class that creates a JNDI named JavaMail Session factory,
which can be used for managing inbound and outbound electronic mail
messages via JavaMail APIs.  All messaging environment properties
described in the JavaMail Specification may be passed to the Session
factory; however the following properties are the most commonly used:


mail.smtp.host - Hostname for outbound transport
    connections.  Defaults to localhost if not specified.

This factory can be configured in a
<Context> element in your conf/server.xml
configuration file.  An example of factory configuration is:
<Resource name="mail/smtp" auth="CONTAINER"
          type="jakarta.mail.Session"/>
<ResourceParams name="mail/smtp">
  <parameter>
    <name>factory</name>
    <value>org.apache.naming.factory.MailSessionFactory</value>
  </parameter>
  <parameter>
    <name>mail.smtp.host</name>
    <value>mail.mycompany.com</value>
  </parameter>
</ResourceParams>

Author:
Craig R. McClanahan/**
 * <p>Factory class that creates a JNDI named JavaMail Session factory,
 * which can be used for managing inbound and outbound electronic mail
 * messages via JavaMail APIs.  All messaging environment properties
 * described in the JavaMail Specification may be passed to the Session
 * factory; however the following properties are the most commonly used:</p>
 * <ul>
 * <li>
 * <li><strong>mail.smtp.host</strong> - Hostname for outbound transport
 *     connections.  Defaults to <code>localhost</code> if not specified.</li>
 * </ul>
 *
 * <p>This factory can be configured in a
 * <code>&lt;Context&gt;</code> element in your <code>conf/server.xml</code>
 * configuration file.  An example of factory configuration is:</p>
 * <pre>
 * &lt;Resource name="mail/smtp" auth="CONTAINER"
 *           type="jakarta.mail.Session"/&gt;
 * &lt;ResourceParams name="mail/smtp"&gt;
 *   &lt;parameter&gt;
 *     &lt;name&gt;factory&lt;/name&gt;
 *     &lt;value&gt;org.apache.naming.factory.MailSessionFactory&lt;/value&gt;
 *   &lt;/parameter&gt;
 *   &lt;parameter&gt;
 *     &lt;name&gt;mail.smtp.host&lt;/name&gt;
 *     &lt;value&gt;mail.mycompany.com&lt;/value&gt;
 *   &lt;/parameter&gt;
 * &lt;/ResourceParams&gt;
 * </pre>
 *
 * @author Craig R. McClanahan
 */
public class MailSessionFactory implements ObjectFactory {


    
The Java type for which this factory knows how to create objects.
/**
     * The Java type for which this factory knows how to create objects.
     */
    protected static final String factoryType = "jakarta.mail.Session";


    
Create and return an object instance based on the specified
characteristics.
Params:
refObj – Reference information containing our parameters, or null
 if there are no parameters
name – The name of this object, relative to context, or null
 if there is no name
context – The context to which name is relative, or null if name
 is relative to the default initial context
env – Environment variables, or null if there are none
Throws:
Exception – if an error occurs during object creation/**
     * Create and return an object instance based on the specified
     * characteristics.
     *
     * @param refObj Reference information containing our parameters, or null
     *  if there are no parameters
     * @param name The name of this object, relative to context, or null
     *  if there is no name
     * @param context The context to which name is relative, or null if name
     *  is relative to the default initial context
     * @param env Environment variables, or null if there are none
     *
     * @exception Exception if an error occurs during object creation
     */
    @Override
    public Object getObjectInstance(Object refObj, Name name, Context context,
            Hashtable<?,?> env) throws Exception {

        // Return null if we cannot create an object of the requested type
        final Reference ref = (Reference) refObj;
        if (!ref.getClassName().equals(factoryType))
            return null;

        // Create a new Session inside a doPrivileged block, so that JavaMail
        // can read its default properties without throwing Security
        // exceptions.
        //
        // Bugzilla 31288, 33077: add support for authentication.
        return AccessController.doPrivileged((PrivilegedAction<Session>) () -> {

            // Create the JavaMail properties we will use
            Properties props = new Properties();
            props.put("mail.transport.protocol", "smtp");
            props.put("mail.smtp.host", "localhost");

            String password = null;

            Enumeration<RefAddr> attrs = ref.getAll();
            while (attrs.hasMoreElements()) {
                RefAddr attr = attrs.nextElement();
                if ("factory".equals(attr.getType())) {
                    continue;
                }

                if ("password".equals(attr.getType())) {
                    password = (String) attr.getContent();
                    continue;
                }

                props.put(attr.getType(), attr.getContent());
            }

            Authenticator auth = null;
            if (password != null) {
                String user = props.getProperty("mail.smtp.user");
                if(user == null) {
                    user = props.getProperty("mail.user");
                }

                if(user != null) {
                    final PasswordAuthentication pa = new PasswordAuthentication(user, password);
                    auth = new Authenticator() {
                            @Override
                            protected PasswordAuthentication getPasswordAuthentication() {
                                return pa;
                            }
                        };
                }
            }

            // Create and return the new Session object
            Session session = Session.getInstance(props, auth);
            return session;

        });
    }
}