/*
    * 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 examples;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.Reader;
  import org.apache.commons.net.pop3.POP3Client;
  import org.apache.commons.net.pop3.POP3MessageInfo;
  
  /***
   * This is an example program demonstrating how to use the POP3Client class.
   * This program connects to a POP3 server and retrieves the message
   * headers of all the messages, printing the From: and Subject: header
   * entries for each message.
   * <p>
   * Usage: messages <pop3 server hostname> <username> <password>
   * <p>
   ***/
  public final class messages
  {
  
      public static final void printMessageInfo(BufferedReader reader, int id)
      throws IOException
      {
          String line, lower, from, subject;
  
          from = "";
          subject = "";
  
          while ((line = reader.readLine()) != null)
          {
              lower = line.toLowerCase();
              if (lower.startsWith("from: "))
                  from = line.substring(6).trim();
              else if (lower.startsWith("subject: "))
                  subject = line.substring(9).trim();
          }
  
          System.out.println(Integer.toString(id) + " From: " + from +
                             "  Subject: " + subject);
      }
  
      public static final void main(String[] args)
      {
          int message;
          String server, username, password;
          POP3Client pop3;
          Reader reader;
          POP3MessageInfo[] messages;
  
          if (args.length < 3)
          {
              System.err.println(
                  "Usage: messages <pop3 server hostname> <username> <password>");
              System.exit(1);
          }
  
          server = args[0];
          username = args[1];
          password = args[2];
  
          pop3 = new POP3Client();
          // We want to timeout if a response takes longer than 60 seconds
          pop3.setDefaultTimeout(60000);
  
          try
          {
              pop3.connect(server);
          }
          catch (IOException e)
          {
              System.err.println("Could not connect to server.");
              e.printStackTrace();
              System.exit(1);
          }
  
          try
          {
              if (!pop3.login(username, password))
              {
                  System.err.println("Could not login to server.  Check password.");
                  pop3.disconnect();
                  System.exit(1);
              }
 
             messages = pop3.listMessages();
 
             if (messages == null)
             {
                 System.err.println("Could not retrieve message list.");
                 pop3.disconnect();
                 System.exit(1);
             }
             else if (messages.length == 0)
             {
                 System.out.println("No messages");
                 pop3.logout();
                 pop3.disconnect();
                 System.exit(1);
             }
 
             for (message = 0; message < messages.length; message++)
             {
                 reader = pop3.retrieveMessageTop(messages[message].number, 0);
 
                 if (reader == null)
                 {
                     System.err.println("Could not retrieve message header.");
                     pop3.disconnect();
                     System.exit(1);
                 }
 
                 printMessageInfo(new BufferedReader(reader), messages[message].number);
             }
 
             pop3.logout();
             pop3.disconnect();
         }
         catch (IOException e)
         {
             e.printStackTrace();
             System.exit(1);
         }
     }
 }