/*
    * 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.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.net.SocketException;
  import java.net.UnknownHostException;
  import org.apache.commons.net.tftp.TFTP;
  import org.apache.commons.net.tftp.TFTPClient;
  
  /***
   * This is an example of a simple Java tftp client using NetComponents.
   * Notice how all of the code is really just argument processing and
   * error handling.
   * <p>
   * Usage: tftp [options] hostname localfile remotefile
   * hostname   - The name of the remote host
   * localfile  - The name of the local file to send or the name to use for
   *              the received file
   * remotefile - The name of the remote file to receive or the name for
   *              the remote server to use to name the local file being sent.
   * options: (The default is to assume -r -b)
   *        -s Send a local file
   *        -r Receive a remote file
   *        -a Use ASCII transfer mode
   *        -b Use binary transfer mode
   * <p>
   ***/
  public final class tftp
  {
      static final String USAGE =
          "Usage: tftp [options] hostname localfile remotefile\n\n" +
          "hostname   - The name of the remote host\n" +
          "localfile  - The name of the local file to send or the name to use for\n" +
          "\tthe received file\n" +
          "remotefile - The name of the remote file to receive or the name for\n" +
          "\tthe remote server to use to name the local file being sent.\n\n" +
          "options: (The default is to assume -r -b)\n" +
          "\t-s Send a local file\n" +
          "\t-r Receive a remote file\n" +
          "\t-a Use ASCII transfer mode\n" +
          "\t-b Use binary transfer mode\n";
  
      public final static void main(String[] args)
      {
          boolean receiveFile = true, closed;
          int transferMode = TFTP.BINARY_MODE, argc;
          String arg, hostname, localFilename, remoteFilename;
          TFTPClient tftp;
  
          // Parse options
          for (argc = 0; argc < args.length; argc++)
          {
              arg = args[argc];
              if (arg.startsWith("-"))
              {
                  if (arg.equals("-r"))
                      receiveFile = true;
                  else if (arg.equals("-s"))
                      receiveFile = false;
                  else if (arg.equals("-a"))
                      transferMode = TFTP.ASCII_MODE;
                  else if (arg.equals("-b"))
                      transferMode = TFTP.BINARY_MODE;
                  else
                  {
                      System.err.println("Error: unrecognized option.");
                      System.err.print(USAGE);
                      System.exit(1);
                  }
              }
              else
                  break;
          }
  
          // Make sure there are enough arguments
          if (args.length - argc != 3)
          {
              System.err.println("Error: invalid number of arguments.");
              System.err.print(USAGE);
              System.exit(1);
          }
 
         // Get host and file arguments
         hostname = args[argc];
         localFilename = args[argc + 1];
         remoteFilename = args[argc + 2];
 
         // Create our TFTP instance to handle the file transfer.
         tftp = new TFTPClient();
 
         // We want to timeout if a response takes longer than 60 seconds
         tftp.setDefaultTimeout(60000);
 
         // Open local socket
         try
         {
             tftp.open();
         }
         catch (SocketException e)
         {
             System.err.println("Error: could not open local UDP socket.");
             System.err.println(e.getMessage());
             System.exit(1);
         }
 
         // We haven't closed the local file yet.
         closed = false;
 
         // If we're receiving a file, receive, otherwise send.
         if (receiveFile)
         {
             FileOutputStream output = null;
             File file;
 
             file = new File(localFilename);
 
             // If file exists, don't overwrite it.
             if (file.exists())
             {
                 System.err.println("Error: " + localFilename + " already exists.");
                 System.exit(1);
             }
 
             // Try to open local file for writing
             try
             {
                 output = new FileOutputStream(file);
             }
             catch (IOException e)
             {
                 tftp.close();
                 System.err.println("Error: could not open local file for writing.");
                 System.err.println(e.getMessage());
                 System.exit(1);
             }
 
             // Try to receive remote file via TFTP
             try
             {
                 tftp.receiveFile(remoteFilename, transferMode, output, hostname);
             }
             catch (UnknownHostException e)
             {
                 System.err.println("Error: could not resolve hostname.");
                 System.err.println(e.getMessage());
                 System.exit(1);
             }
             catch (IOException e)
             {
                 System.err.println(
                     "Error: I/O exception occurred while receiving file.");
                 System.err.println(e.getMessage());
                 System.exit(1);
             }
             finally
             {
                 // Close local socket and output file
                 tftp.close();
                 try
                 {
                     output.close();
                     closed = true;
                 }
                 catch (IOException e)
                 {
                     closed = false;
                     System.err.println("Error: error closing file.");
                     System.err.println(e.getMessage());
                 }
             }
 
             if (!closed)
                 System.exit(1);
 
         }
         else
         {
             // We're sending a file
             FileInputStream input = null;
 
             // Try to open local file for reading
             try
             {
                 input = new FileInputStream(localFilename);
             }
             catch (IOException e)
             {
                 tftp.close();
                 System.err.println("Error: could not open local file for reading.");
                 System.err.println(e.getMessage());
                 System.exit(1);
             }
 
             // Try to send local file via TFTP
             try
             {
                 tftp.sendFile(remoteFilename, transferMode, input, hostname);
             }
             catch (UnknownHostException e)
             {
                 System.err.println("Error: could not resolve hostname.");
                 System.err.println(e.getMessage());
                 System.exit(1);
             }
             catch (IOException e)
             {
                 System.err.println(
                     "Error: I/O exception occurred while sending file.");
                 System.err.println(e.getMessage());
                 System.exit(1);
             }
             finally
             {
                 // Close local socket and input file
                 tftp.close();
                 try
                 {
                     input.close();
                     closed = true;
                 }
                 catch (IOException e)
                 {
                     closed = false;
                     System.err.println("Error: error closing file.");
                     System.err.println(e.getMessage());
                 }
             }
 
             if (!closed)
                 System.exit(1);
 
         }
 
     }
 
 }