//////////////////////////////////////////////////////////////////////
// SPONSupervisor.java                                              //
// --Supervisor Process used to maintain the SPON Network--         //
//                                                                  //
// Supervised Peer-to-peer Overlay Network (SPON) Simulator         //
//                                                                  //
//                                                                  //
// Computer Science M.S.E. Project                                  //
// Programmed by: Joey Chau                                         //
// Copyright: February, 2003                                        //
//                                                                  //
// Research Advisor: Christian Scheideler                           //
//                   Computer Science                               //
//                   Johns Hopkins University                       //
//////////////////////////////////////////////////////////////////////

import java.io.*;
import java.net.*;
import java.util.*;

/**
   The Actual Supervisor process used to maintain the SPON Network
*/
class SPONSupervisor 
{
    static boolean debug = true;
    
    static void dbg(String str){
	if(debug) {
	    System.out.println(str);
	    System.out.flush();
	}
    }

    public static void main(String argv[]) throws Exception
    {
	// Broadcast Communication
	Socket mTopRoot = null;
	Socket mBottomRoot = null;
	ServerSocket mServerSocket;
	boolean mTon = false; // boolean marker for whether Top Node is on

	// Maintenance Communication
	DatagramSocket mUDPSocket;
	RootVector myRoot;
	
	// General Information
	BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));
	InetAddress mLocalAddress;
	mLocalAddress = InetAddress.getLocalHost();
	System.out.println( "Running SPON Supervisor on <" + mLocalAddress + ">" );
	mServerSocket = new ServerSocket( 7766 );
	mServerSocket.setSoTimeout( 50 );
	dbg( "Started Server: " + mServerSocket.toString() );
	myRoot = new RootVector( mLocalAddress.getHostAddress() );
	mUDPSocket = new DatagramSocket( 6677, mLocalAddress );
	dbg( "Started Maintenance Socket: " + mUDPSocket.toString() );
	
	while(true) 
	    {
		DatagramPacket mDPacket = new DatagramPacket( new byte[75], 75);
		String sMess;
		StringTokenizer token;
		String messType;
		InetAddress senderAddress;
		int senderPort;
		int TimeoutLength = 50;

		mUDPSocket.setSoTimeout( TimeoutLength );
		try {
		  mUDPSocket.receive( mDPacket );
		  sMess = new String( mDPacket.getData(), 0, mDPacket.getLength() );
		  // Diagnostic
		  dbg( " Diagnostic:"+sMess+" length "+sMess.length()+" "+mDPacket.getLength() );
		  //
		  senderAddress = mDPacket.getAddress();
		  token = new StringTokenizer( new String( sMess ), ">" );
		  messType = token.nextToken();
		  dbg("Received: " + sMess + " from " + senderAddress);
		  if( messType.equals("JOIN") ) {
		    // Join Stuff
		    String comString = new String();
		    String newNode = token.nextToken();
		    dbg("New Node: " + newNode );
		    senderAddress = InetAddress.getByName( newNode );
		    comString = myRoot.join( newNode );
		    StringTokenizer comStack = new StringTokenizer( comString, "|" ); 
		    while( comStack.hasMoreTokens() ) {
		      String newInfo = comStack.nextToken();
		      dbg( "Token: " + newInfo + " length " + newInfo.length() );
		      StringTokenizer comToken = 
			new StringTokenizer( newInfo, "," );
		      String cMess = comToken.nextToken();
		      String cDest = comToken.nextToken();
		      dbg( "MESSAGE: " + cMess + " len: " + cMess.length() );
		      InetAddress destAddy = InetAddress.getByName( cDest );
		      
		      DatagramPacket cPacket = new DatagramPacket( cMess.getBytes(), 
								   cMess.length(), 
								   destAddy, 
								   6677 );
		      mUDPSocket.send( cPacket ); 
		      
		    }
		    dbg( myRoot.toString() );
		    
		  }
		  else if( messType.equals( "TOP0" ) ) {
		    String newNode = token.nextToken();
		    if( newNode.equals(" ") ) {
		      mTon = false;
		    }
		    else {
		      InetAddress newTop = InetAddress.getByName( newNode );
		      mTopRoot = new Socket( newTop, 7766 );
		      dbg( "Connected new Top Node: " + mTopRoot.toString() );
		      mTon = true;
		    }
		  }
		  else if( messType.equals( "LEAV" ) ) {
		    String comString = new String();
		    StringTokenizer reqLeaveTok = new StringTokenizer
		      ( token.nextToken(),"+" );
		    Node byeNode = new Node();

		    byeNode.parseString( reqLeaveTok.nextToken() );
		    String parentNode = reqLeaveTok.nextToken();
		    dbg( "Host: " + byeNode +
			 " with Parent " + parentNode +
			 ", requesting to Leave" );
		    comString = myRoot.replace( byeNode, parentNode );
		    StringTokenizer comStack = new StringTokenizer( comString, "|" ); 
		    while( comStack.hasMoreTokens() ) {
		      String newInfo = comStack.nextToken();
		      dbg( "Token: " + newInfo + " length " + newInfo.length() );
		      StringTokenizer comToken = 
			new StringTokenizer( newInfo, "," );
		      String cMess = comToken.nextToken();
		      String cDest = comToken.nextToken();
		      dbg( "MESSAGE: " + cMess + " len: " + cMess.length() );
		      InetAddress destAddy = InetAddress.getByName( cDest );
		      
		      DatagramPacket cPacket = new DatagramPacket( cMess.getBytes(), 
								   cMess.length(), 
								   destAddy, 
								   6677 );
		      mUDPSocket.send( cPacket ); 
		      
		    }
		    dbg( myRoot.toString() );
		  }
		  else if( messType.equals( "INFO" ) ) {
		    String infoNode = token.nextToken();
		    Node newInfo = new Node();
		    newInfo.parseString( infoNode );
		    myRoot.update( newInfo );
		  }
		  else {
		    dbg( "Recieved unknown packet: " + mDPacket );
		  }
		} // try
		catch( SocketTimeoutException e ) {
		}

		if( inFromUser.ready() ) {
		  String userInput = inFromUser.readLine();
		  if( userInput.equals( "diagnostic" ) ) {
		    dbg( "Root Status "+myRoot.toString() );
		  }
		  else {
		    if( mTon ) {
		      DataOutputStream outCom = new DataOutputStream( mTopRoot.getOutputStream() );
		      outCom.writeBytes( "[SUPERVISOR]:" + userInput + "\n" );
		    }
		  }
		}
		
		mServerSocket.setSoTimeout( TimeoutLength );
		try {
		  Socket connectionSocket = mServerSocket.accept();
		  BufferedReader inFromServer = 
		    new BufferedReader( new InputStreamReader( connectionSocket.getInputStream() ) );
		  //if( inFromServer.ready() ) {
		    String incoming = inFromServer.readLine();
		    System.out.println( "Broadcast: " + incoming );
		    if( myRoot.size() > 0 && mTon) {
		      DataOutputStream outCom = new DataOutputStream( mTopRoot.getOutputStream() );
		      outCom.writeBytes( incoming + "\n" );
		    }
		    
		    //}
		    connectionSocket.close();
		}
		catch( SocketTimeoutException e ) {
		}
	    }
    }
}