package net.sourceforge.rconed;

 import net.sourceforge.rconed.exception.BadRcon;

 import net.sourceforge.rconed.exception.ResponseEmpty;

 import java.io.*;

 import java.net.*;

 import java.nio.ByteBuffer;

 import java.nio.ByteOrder;

 /**

  * User: oscahie (aka PiTaGoRaS)<br/>

  * Date: 03-jan-2005<br/>

  * Time: 19:11:40<br/>

  * version: 0.4<br/>

  * Rcon library for Source Engine based games<br/> 

  */

 public class SourceRcon {

     final static int SERVERDATA_EXECCOMMAND = 2;

     final static int SERVERDATA_AUTH = 3;

     final static int SERVERDATA_RESPONSE_VALUE = 0;

     final static int SERVERDATA_AUTH_RESPONSE = 2;

     final static int RESPONSE_TIMEOUT = 2000;

     final static int MULTIPLE_PACKETS_TIMEOUT = 300;

     static Socket rconSocket = null;

     static InputStream in = null;

     static OutputStream out = null;

     /**

      * Send the RCON command to the game server (must have been previously authed with the correct rcon_password)

      *

      * @param ipStr     The IP (as a String) of the machine where the RCON command will go.

      * @param port      The port of the machine where the RCON command will go.

      * @param password  The RCON password.

      * @param command   The RCON command (without the rcon prefix).

      * @return The reponse text from the server after trying the RCON command.

      * @throws IOException  if there was an input/output problem

      */

     public static String send(String ipStr, int port, String password, String command) throws BadRcon, ResponseEmpty, IOException {

         return send(ipStr, port, password, command, 0);

     }

     /**

      * Send the RCON command to the game server (must have been previously authed with the correct rcon_password)

      *

      * @param ipStr     The IP (as a String) of the machine where the RCON command will go.

      * @param port      The port of the machine where the RCON command will go.

      * @param password  The RCON password.

      * @param command   The RCON command (without the rcon prefix).

      * @param localPort The port of the local machine to use for sending out the RCON request.

      * @return The reponse text from the server after trying the RCON command.

      * @throws IOException  if there was an input/output problem

      */

     public static String send(String ipStr, int port, String password, String command, int localPort) throws BadRcon, ResponseEmpty, IOException {

         String response = "";

             rconSocket = new Socket();

             InetAddress addr = InetAddress.getLocalHost();

             byte[] ipAddr = addr.getAddress();

             InetAddress inetLocal = InetAddress.getByAddress(ipAddr);

             rconSocket.bind(new InetSocketAddress(inetLocal, localPort));

             rconSocket.connect(new InetSocketAddress(ipStr, port), 1000);

             out = rconSocket.getOutputStream();

             in = rconSocket.getInputStream();

             rconSocket.setSoTimeout(RESPONSE_TIMEOUT);

             if (rcon_auth(password)) {

                 // We are now authed

                 ByteBuffer[] resp = sendCommand(command);

                 // Close socket handlers, we don't need them more

                 out.close(); in.close(); rconSocket.close();

                 if (resp != null) {

                     response = assemblePackets(resp);

                     if (response.length() == 0) {

                         throw new ResponseEmpty();

                     }

                 }

             }

             else {

                 throw new BadRcon();

             }

         return response;

     }

     private static ByteBuffer[] sendCommand(String command) throws IOException {

         byte[] request = constructPacket(2, SERVERDATA_EXECCOMMAND, command);

         ByteBuffer[] resp = new ByteBuffer[128];

         int i = 0;

             out.write(request);

             resp[i] = receivePacket();  // First and maybe the unique response packet

             try {

                 // We don't know how many packets will return in response, so we'll

                 // read() the socket until TimeoutException occurs.

                 rconSocket.setSoTimeout(MULTIPLE_PACKETS_TIMEOUT);

                 while (true) {

                     resp[++i] = receivePacket();

                 }

             } catch (SocketTimeoutException e) {

                 // No more packets in the response, go on

                 return resp;

             }

     }

     private static byte[] constructPacket(int id, int cmdtype, String s1) {

         ByteBuffer p = ByteBuffer.allocate(s1.length() + 16);

         p.order(ByteOrder.LITTLE_ENDIAN);

         // length of the packet

         p.putInt(s1.length() + 12);

         // request id

         p.putInt(id);

         // type of command

         p.putInt(cmdtype);

         // the command itself

         p.put(s1.getBytes());

         // two null bytes at the end

         p.put((byte) 0x00);

         p.put((byte) 0x00);

         // null string2 (see Source protocol)

         p.put((byte) 0x00);

         p.put((byte) 0x00);

         return p.array();

     }

     private static ByteBuffer receivePacket() throws IOException {

         ByteBuffer p = ByteBuffer.allocate(4120);

         p.order(ByteOrder.LITTLE_ENDIAN);

         byte[] length = new byte[4];

         if (in.read(length, 0, 4) != 4) {

                 return null;

         }

         // Now we've the length of the packet, let's go read the bytes

         p.put(length);

         int i = 0;

         while (i < p.getInt(0)) {

             p.put((byte) in.read());

             i++;

         }

         return p;

     }

     private static String assemblePackets(ByteBuffer[] packets) {

     // Return the text from all the response packets together

         String response = "";

         for (int i = 0; i < packets.length; i++) {

             if (packets[i] != null) {

                 response = response.concat(new String(packets[i].array(), 12, packets[i].position()-14));

             }

         }

         return response;

     }

     private static boolean rcon_auth(String rcon_password) throws IOException {

         byte[] authRequest = constructPacket(1337, SERVERDATA_AUTH, rcon_password);

         ByteBuffer response = ByteBuffer.allocate(64);

             out.write(authRequest);

             response = receivePacket(); // junk response packet

             response = receivePacket();

             // Lets see if the received request_id is leet enougth ;)

             if ((response.getInt(4) == 1337) && (response.getInt(8) == SERVERDATA_AUTH_RESPONSE)) {

                 return true;

             }

         return false;

     }

 }