import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
import java.util.Calendar;


public class Client extends Frame implements ActionListener{

	private boolean login = false;
	private Color bg = new Color(176, 196, 227);
	private String rightNow;
	private InetAddress clientAddress;
	private Socket connection;
	private DataInputStream in;
	private DataOutputStream out;
	private recThread receiver;
	
	private Button B_login = new Button("Login");
	private Button B_logout = new Button("Logout");
	private Button B_send = new Button("Send");
	
	private Label userName = new Label("User Name:");
	private TextField getUserName = new TextField();	// 獲取用戶名
	private Label svrIP = new Label("Server IP:");
	private TextField getSvrIP = new TextField();		// 獲取服務器 IP 地址
	private Label svrPort = new Label("Server Port:");
	private TextField getSvrPort = new TextField();		// 獲取服務器端口
	private TextArea input = new TextArea();			// 輸入文本框
	private TextArea output = new TextArea();			// 輸出文本框
	private Label user = new Label("User (0)");
	private List list = new List();
	
	// 用于接收服務器消息的線程類
	private class recThread extends Thread
	{
		public recThread()
		{
			start();
		}
		public void run()
		{
			try{
				while(login){
					String line = in.readUTF();
					rightNow = Calendar.getInstance().getTime().toLocaleString();
					if(line.charAt(0) == 'Q'){
						if(line.length() == 1){
							// 退出
							connection.close();
							rightNow = Calendar.getInstance().getTime().toLocaleString();
							output.append(rightNow+"\nLog out.\n\n");
							login = false;
							list.clear();
							getUserName.setEditable(true);
							getSvrIP.setEditable(true);
							getSvrPort.setEditable(true);
							B_login.setEnabled(true);
							B_send.setEnabled(false);
							B_logout.setEnabled(false);
							break;
						}
						else{
							// 其他用戶退出
							list.remove(line.substring(2));
							user.setText("User ("+list.getItemCount()+")");
							output.append(rightNow+"\n"+line.substring(2)+" log out.\n\n");
						}
					}
					else if(line.charAt(0) == 'L'){
						// 其他用戶登錄
						list.add(line.substring(2));
						user.setText("User ("+list.getItemCount()+")");
						output.append(rightNow+"\n"+line.substring(2)+" log in.\n\n");
					}
					else{
						output.append(rightNow+"\n"+line+"\n\n");
					}
				}
			}catch(SocketException se){
				rightNow = Calendar.getInstance().getTime().toLocaleString();
				output.append(rightNow+"\nConnection closed.\n\n");
				login = false;
				list.clear();
				getUserName.setEditable(true);
				getSvrIP.setEditable(true);
				getSvrPort.setEditable(true);
				B_login.setEnabled(true);
				B_send.setEnabled(false);
				B_logout.setEnabled(false);				
			}catch (IOException ioe){
				output.append("Error: "+ioe+"\n\n");
			}
		}
	}
	// 響應關閉按鈕的內部類
	private class WindowCloser extends WindowAdapter
	{
		public void windowClosing(WindowEvent we)
		{
			System.exit(0);
		}
	}
	// 布局設置方法，在構造方法里面調用
	private void setup()
	{
		Panel top1 = new Panel();
		top1.setLayout(new BorderLayout());
		top1.add("West", userName);
		userName.setBackground(bg);
		top1.add("Center", getUserName);
		getUserName.setBackground(bg);
		Panel top2 = new Panel();
		top2.setLayout(new BorderLayout());
		top2.add("West", svrIP);
		svrIP.setBackground(bg);
		top2.add("Center", getSvrIP);
		getSvrIP.setBackground(bg);
		Panel top3 = new Panel();
		top3.setLayout(new BorderLayout());
		top3.add("West", svrPort);
		svrPort.setBackground(bg);
		top3.add("Center", getSvrPort);
		getSvrPort.setBackground(bg);
		Panel top4 = new Panel();
		top4.setLayout(new BorderLayout());
		top4.add("North", top1);
		top4.add("Center", top2);
		top4.add("East", top3);
		
		Panel east = new Panel();
		east.setLayout(new BorderLayout());
		east.add("North", user);
		user.setBackground(bg);
		east.add("Center", list);
		list.setBackground(bg);
		
		Panel center = new Panel();
		center.setLayout(new BorderLayout());
		center.add("Center", output);
		output.setBackground(bg);
		center.add("South", input);
		input.setBackground(bg);
		center.add("East", east);
		east.setBackground(bg);
		
		Panel south = new Panel();
		south.setLayout(new FlowLayout());
		south.add(B_login);
		B_login.setBackground(bg);
		south.add(B_send);
		B_send.setBackground(bg);
		south.add(B_logout);
		B_logout.setBackground(bg);
		
		setLayout(new BorderLayout());
		add("North", top4);
		add("Center", center);
		add("South", south);

		setBackground(bg);
		
	}
	// 構造方法
	public Client()throws UnknownHostException, IOException
	{
		super("Chat Room Client");
		
		login = false;
		clientAddress = InetAddress.getLocalHost();
		byte[] ip = clientAddress.getAddress();
		String strIP = (ip[0]&0xFF)+"."+(ip[1]&0xFF)+
				"."+(ip[2]&0xFF)+"."+(ip[3]&0xFF);
		getSvrIP.setText(strIP);
		getSvrPort.setText("8888");
		getUserName.setText("User");

		output.setEditable(false);	// 輸出文本框設為只讀屬性	
		B_login.addActionListener(this);
		B_send.addActionListener(this);
		B_send.setEnabled(false);
		B_logout.addActionListener(this);
		B_logout.setEnabled(false);
		addWindowListener(new WindowCloser());
		
		getUserName.setText("User");
		setup();
		pack();
		setSize(500, 600);
		show();
		
		rightNow = Calendar.getInstance().getTime().toLocaleString();
		output.append(rightNow+"\nClient started.\nMy IP Address is "+strIP+"\n\n");
	}
	// 登錄
	private void logIn()
	{
		if(login) return;
		boolean accepted = false, refused = false;
		String line= new String("");
		try{
			connection = new Socket(getSvrIP.getText(), 
					Integer.parseInt(getSvrPort.getText()));
			in = new DataInputStream(connection.getInputStream());
			out = new DataOutputStream(connection.getOutputStream());
			out.writeUTF("L "+getUserName.getText());
			while(!accepted && !refused){
				line = in.readUTF();
				if(line.charAt(0) == 'R'){
					refused = true;
				}
				if(line.charAt(0) == 'A'){
					accepted = true;
				}
			}
			if(refused){
				rightNow = Calendar.getInstance().getTime().toLocaleString();
				output.append(rightNow+"\nUser name error.\n\n");
			}
			if(accepted){
				rightNow = Calendar.getInstance().getTime().toLocaleString();
				output.append(rightNow+"\nSuccessfully log in.\n\n");
				login = true;
				// 獲取當前在線用戶列表
				String[] str = line.split(" ");
				for (int i = 1; i < str.length; i ++){
					list.add(str [i]);
				}
				user.setText("User ("+list.getItemCount()+")");
				
				getUserName.setEditable(false);
				getSvrIP.setEditable(false);
				getSvrPort.setEditable(false);
				B_login.setEnabled(false);
				B_send.setEnabled(true);
				B_logout.setEnabled(true);
				receiver = new recThread();
			}			
		}catch(ConnectException ce){
			rightNow = Calendar.getInstance().getTime().toLocaleString();
			output.append(rightNow+"\nHost not found\n\n");
		}catch(UnknownHostException uhe){
			rightNow = Calendar.getInstance().getTime().toLocaleString();
			output.append(rightNow+"\nHost not found\n\n");
		}catch(IOException ioe){
			output.append("Error: "+ioe+"\n\n");
		}
	}
	// 發送消息
	private void sendMsg()
	{
		if(!login) return;
		try{
			out.writeUTF("M "+input.getText());
			input.setText("");
		}catch (IOException ioe){
			output.append("Error: "+ioe+"\n\n");
		}
	}
	// 退出登錄
	private void Quit()
	{
		if(!login) return;
		try{
			out.writeUTF("Q");
		}catch (IOException ioe){
			output.append("Error: "+ioe+"\n\n");
		}
	}
	// 消息處理方法
	public void actionPerformed(ActionEvent e)
	{
		if(e.getSource() == B_login){
			logIn();
		}
		if(e.getSource() == B_send){
			sendMsg();
		}
		if(e.getSource() == B_logout){
			Quit();
		}
	}
	
	// 主方法
	public static void main(String args [])throws UnknownHostException, IOException
	{
		Client c = new Client();
	}
}