/**
 * This Class implements basic network server functionality
 * @version 	1.0
 * @author Tim Stefanini
 */
 
import java.io.*;
import java.net.*;

public abstract class GenericService implements Runnable, Cloneable, ServiceInterface
{
    //++ Public Methods
    public GenericService ()
    {	System.out.println("sTARTING GenericService Constructor");
    	mfIsWorking = false;
        mfContinueToListen = true;
    	System.out.println("Called GenericService Constructor");
    }
    
    public void close()
    {	try
        {
             if (clientSocket != null)
                  clientSocket.close();
             clientSocket = null;
             clientInput = null;
             clientOutput = null;
        }//end try
        catch (Exception e)
        { 
        }//end catch
    }//end close()
    
    public synchronized void ShutDown()
    {	mfContinueToListen = false;
        try
        {    InetAddress aAddress = InetAddress.getLocalHost();
             Socket s = new Socket(aAddress, miPort);
             OutputStream out = s.getOutputStream();
             Thread.currentThread().sleep (100);
             
             serverInstance = null;
        }//end try
        catch (Exception e)
        {    System.out.println("ShutDown failure" + e);
             e.printStackTrace();
        }//end catch
    }//end Shutdown()
    
    /** Return client connection status */
    
    public boolean clientIsOpen()
    {    return clientSocket != null;
    }//end clientIsOpen()
    
    final public void run()
    {	if (serverSocket != null)
        {    Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
             System.out.print("Server starts " + serverSocket + "\n");
             while (true)
             {   if (mfIsActive){
                     try
                     {
                         //Create new Thread to handle request Note: This may be too much overhead 
                         //for simple requests
                         Socket ns = serverSocket.accept();
                         if (!mfContinueToListen)
                             break;
                         GenericService n = (GenericService)clone();
                         n.serverSocket = null;
                         n.clientSocket = ns; 
                         //set the new GenericServer's client socket to the 
                         //one returned by accept()
                         Thread oThread = new Thread(n);	
                         oThread.setDaemon(true);
                         oThread.start();
                     }//end try
                     catch(Exception e)
                     {    System.out.print("Server failure\n");
                          e.printStackTrace();
                          try
                          {    serverSocket.close();
                          }//end try
                          catch(IOException e2)
                          {    e.printStackTrace();
                          }//end catch
                          System.out.print("cs="+serverSocket+"\n");
                          break;
                     }//end catch
                 }//end if
                 else {System.out.println("Server not active on port" + miPort);}
                 }//end while
                 mfIsWorking = false;
                 }//end if serverSocket != null
                 else
                 {
                     try
                     {	
                         clientOutput = new PrintStream(
                         new BufferedOutputStream(clientSocket.getOutputStream()), true); 
                         //true = autoflush on newline char+clientInput = new DataInputStream(clientSocket.getInputStream());
                         serviceRequest();
                     }//end try
                     catch(Exception e)
                     {   e.printStackTrace();
                     }//end catch
                 }//end else
                 close();
     }//end run()
                            
     public void Activate()
     {    this.mfIsActive = true;
     }//end Activate()
     
     public void Deactivate()
     {	this.mfIsActive = false;
     }//end Deactivate()
     
     public boolean IsActive()
     {	return mfIsActive;
     }//end IsActive()
     
     public void StartUp()
     {	try
        {    serverSocket = new ServerSocket(0);
             miPort = serverSocket.getLocalPort();
             serverInstance = new Thread(this);
             serverInstance.setDaemon(true);
             serverInstance.start();
             System.out.println("Service started");
        }
        catch (IOException e)
        { e.printStackTrace();
        }//end catch
     }//end startServer()
     
     public void serviceRequest() throws IOException
     {	System.out.println("in serviceRequest for server " + getClass().getName() + "\n");
        String foo = null;
        while ( (foo = clientInput.readLine()) != null) 
        clientOutput.print("server: " + foo + " :server\r\n"); 
        clientOutput.flush();
     }//end serviceRequest()
     
      public Object clone()
    {	try
		{   return super.clone();
		}//end try
		catch (CloneNotSupportedException e)
		{	// this shouldn't happen, since we are Cloneable
			return null;
		}//end catch
    }//end clone()

    //++ Protected Methods
  	protected	int				miPort = -1;

    //++ Private Methods
    //++ Data Members
    /** Socket for communicating with client. */
    private	Socket			clientSocket = null;
    private Thread			serverInstance;
    private ServerSocket	serverSocket;
	private	boolean			mfIsWorking;
	private	boolean			mfContinueToListen;
    private	boolean			mfIsActive = false;

    /** Stream for printing to the client. */
    public	PrintStream		clientOutput;

    /** Buffered stream for reading replies from client. */
    public	DataInputStream		clientInput;
}//end class GenericService