import java.awt.*;
import java.awt.event.*;
import java.io.IOException;
import java.net.*;
import java.util.*;
import javax.swing.*;

/**
 * Ip 4.1.2
 * @author emi-lind
 *
 */
public class ChatServer extends JFrame
{

	private int _port;
	private ServerSocket _serverSocket;
	private JTextArea _outputArea;
	
	/**
	 * Stores all clients connected
	 */
	private ArrayList<ClientHandler> _allClients;
	
	private String _jFrameTitle;
	
	/**
	 * @param args Port
	 */
	public static void main(String[] args)
	{
		new ChatServer(args);
	}
	
	private ChatServer(String[] aArgs)
	{
		this.readCommandLineArgs(aArgs);
		this.createGUI();
		this.initServer();
	}

	/**
	 * Reads the command line
	 * @param aArgs
	 */
	private void readCommandLineArgs(String[] aArgs)
	{
		int port = 2000;
		if (aArgs.length > 0)
		{
			port = Integer.parseInt(aArgs[0]);
		}
		_port = port;
	}
	
	/**
	 * Creates the gui
	 */
	private void createGUI()
	{
		_jFrameTitle = "Server Chat v1.0.";
		setVisible(true);
		setSize(600, 400);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		_outputArea = new JTextArea();
		_outputArea.setEditable(false);
		JScrollPane outScroll = new JScrollPane(_outputArea);
		// Auto scroll
		outScroll.getVerticalScrollBar().addAdjustmentListener(new AdjustmentListener()
		{  
			@Override
			public void adjustmentValueChanged(AdjustmentEvent e)
			{  
				e.getAdjustable().setValue(e.getAdjustable().getMaximum());  
			}
		}); 
		add(outScroll, BorderLayout.CENTER);
		
		validate();
	}
	
	/**
	 * Starts and runs the server
	 */
	private void initServer()
	{
		_allClients = new ArrayList<ClientHandler>();
		try
		{	
			showMessage("Starting server on port: " + _port, false);
			_serverSocket = new ServerSocket(_port);
			_jFrameTitle += " HOST: " + _serverSocket.getInetAddress().getLocalHost().getHostName() + " IP: " +
				_serverSocket.getInetAddress().getLocalHost().getHostAddress() + " ON PORT: " + _port + " CLIENTS: ";
			setTitle(_jFrameTitle + "0");
			while (true)
			{
				Socket connection = _serverSocket.accept(); // Waits  for connection
				showMessage("Connection established with " + connection.getInetAddress() +
						" on port " + connection.getPort(), false);
				ClientHandler ch = new ClientHandler(this, connection);
				_allClients.add(ch);
				setTitle(_jFrameTitle + " CLIENTS: " + _allClients.size());
				
			}
		}
		catch (IOException e)
		{
			showMessage(e.toString(), true);
		}
	}
	

	/**
	 * Prints a message or an error message in System.err or out and in the output. 
	 * @param aErrorMessage The message to print
	 * @param aIsError If the message is an error 
	 */
	public void showMessage(String aMessage, boolean aIsError)
	{
		if (aIsError)
		{
			System.err.println(aMessage);
	    	this._outputArea.append("ERROR: " + aMessage+ "\n");
		}
		else
		{
			System.out.println(aMessage);
	    	this._outputArea.append(aMessage + "\n");
		}
	}
	
	/**
	 * Broadcasts a message to all connected users
	 * @param aMessage The message
	 */
	public synchronized void broadcastMessageToAllClients(String aMessage)
	{
		for (ClientHandler ch : _allClients)
		{
			ch.sendMessage(aMessage);
		}
	}
	
	/**
	 * Kills a  ClientHandler. Does nothing if given ClientHandler doesn't exist
	 * @param aClient the client to kill
	 */
	public synchronized void killClientHandler(ClientHandler aClient)
	{
		if( _allClients.remove(aClient))
		{
			setTitle(_jFrameTitle + " CLIENTS: " + _allClients.size());
			aClient.killThread();
		}
	}
}