/**
*Class Chat is the GUI for this Chat application that implements ActionListener
*to register user actions.
*Internetprogrammering 1 - Course
*@author Martin Carlsson
*/

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



public class Chat extends JFrame implements ActionListener {
    
    private String host; // Server/host to connect to
    private int port; // Port to be used for the connection
    private Socket theSocket;
    private Thread receiveactivity;	
    private static String usage = "usage: java Chat host port\n"+
        "example:java Chat this.is.the.host.address 7000";
        
    private JTextField writeField = new JTextField(46); // Text field for writing messages in
    private JTextArea messageArea = new JTextArea(); // Text area for messages received from the server
    private JScrollPane jsp = new JScrollPane(messageArea); // Scroll pane with the message area
    private JPanel up = new JPanel(),down=new JPanel(); // North and south panels
    private JButton sendButton = new JButton(), quit = new JButton(); // Send and Quit buttons
    private Receiver receiver; 
    private Sender sender; 
    
    
    /*Constructor*/
    public Chat(String host, int port)throws IOException {
        
        this.host=host;
        this.port=port;
        
        /*Container to put everything in*/
        Container con = getContentPane();
        
        // Layout of the north panel
        up.setLayout(new FlowLayout(FlowLayout.RIGHT));
        up.setBackground(Color.lightGray);
        up.add(quit);
        
       // Layout of the south panel
        down.setLayout(new FlowLayout(FlowLayout.RIGHT));
        down.setBackground(Color.lightGray);
        down.add(writeField);
        down.add(sendButton);
        
        
        // Prevent changes in the message area
        messageArea.setEditable(false);
        
        
        // Layout of the text field
        writeField.setText(" ");
        writeField.requestFocus();
        
        
        // Text for the buttons
        sendButton.setText("SEND");
        quit.setText("QUIT");
        
        
        /*Adds listener*/
        sendButton.addActionListener(this);
        quit.addActionListener(this);
        writeField.addActionListener(this);
        
        
        // Adds panels
        con.add(down,BorderLayout.SOUTH);
        con.add(up,BorderLayout.NORTH);
    
    
        //Adds scroll area with text area
        con.add(jsp,BorderLayout.CENTER);
        
        
        //Sets the window size and makes it all visible
        setSize(600,300);
        show();
        
        // Tries to create a socket
        try {
            theSocket = new Socket(host, port);
        }
        catch(UnknownHostException uHe) {
            messageArea.setText("Unable to connect to "+ host + " on " + port +".....closing");
            System.err.println("Unable to connect to "+ host + " on " + port +".....closing");
            setTitle("Java Chat Client");
            try {
                Thread.sleep(3000); // Sleeps awhile to show messages
                System.exit(0); // Then closes
            }
            catch(InterruptedException e) {
            }
        }
        catch (IOException iE) {
            messageArea.setText("Unable to connect to " + host + " on " + port + ".....closing");
            System.err.println("Unable to connect to " + host + " on " + port + ".....closing");
                try{
                Thread.sleep(3000); // Sleeps awhile to show messages
                System.exit(0); // Then closes
            }
            catch(InterruptedException e) {
            }
        }
        sender=new Sender(theSocket); // Creates an instance of class Sender
        receiver=new Receiver(this, theSocket); // Creates an instance of class Receiver
        receiveactivity= new Thread(receiver); 
        receiveactivity.start(); // Starts the Receiver thread
    }
    
    
    // Used to clear the message field
    public void clearWriteField() {
        
        writeField.setText("");
    }
    
    // Message from server
    public void setIncomingMessage(String s) {
        
        messageArea.append("\n" + s);
    }
        
    
    
    /*Decides what will happend when an user action is performed*/	
    public void actionPerformed(ActionEvent ae) {
        if(ae.getSource()==writeField || ae.getSource()==sendButton) {
            try {
                sender.sendAway(writeField.getText().trim());
                clearWriteField();
            }
            catch(Exception e) {
                messageArea.append("\n Not able to send message at this time");
                }
        }
        else if(ae.getSource()==quit) {
            try {
            sender.closeOutStream();
            receiver.closeInStream();
            
                if(theSocket!=null) 
                    theSocket.close();
            }
            catch(IOException iE) {
                messageArea.append("\n Please wait...having some trouble closing..");
            }
            catch(NullPointerException nE) {
                messageArea.append("\n Please wait...having some trouble closing..");
            }
        System.exit(0);	
        }
            
                
            
    } 


    
    // Main
    public static void main (String[] args) {
        
        int port=2000; // default port
        String host="localhost"; // default host
        String portText = "port must be a number between"+
                    "0 and 65535";
        System.out.println("Welcome to Chat\n" +usage+"\n");  
        
        try {
            //If there are 2 or more arguments
            if(args.length>=2){
                host=args[0];
                port =Integer.parseInt(args[1]);
            }
            //If there is 1 argument, i.e. host
            else if(args.length==1){
                host=args[0];
            }
            // To make sure the port is within the valid range
            if(port > 65535 || port < 0)
                System.err.println(portText);
            else
                new Chat(host, port); // starts
        }
        catch(NumberFormatException nFe) {
            System.err.println(portText);
        }
        catch(Exception e){
            System.err.println(usage);  
        }	
        
    }
}//End class Chat