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

/*
 * 聊天服務端的主框架類
 */
public class ChatServer extends JFrame implements ActionListener{

	public static int port = 8888;//服務端的偵聽端口

	ServerSocket serverSocket;//服務端Socket
	Image icon;//程序圖標
	JComboBox combobox;//選擇發送消息的接受者
	JTextArea messageShow;//服務端的信息顯示
	JScrollPane messageScrollPane;//信息顯示的滾動條
	JTextField showStatus;//顯示用戶連接狀態
	JLabel sendToLabel,messageLabel;
	JTextField sysMessage;//服務端消息的發送
	JButton sysMessageButton;//服務端消息的發送按鈕
	UserLinkList userLinkList;//用戶鏈表

	//建立菜單欄
	JMenuBar jMenuBar = new JMenuBar(); 
	//建立菜單組
	JMenu serviceMenu = new JMenu ("服務(V)"); 
	//建立菜單項
	JMenuItem portItem = new JMenuItem ("端口設置(P)");
	JMenuItem startItem = new JMenuItem ("啟動服務(S)");
	JMenuItem stopItem=new JMenuItem ("停止服務(T)");
	JMenuItem exitItem=new JMenuItem ("退出(X)");
	
	JMenu helpMenu=new JMenu ("幫助(H)");
	JMenuItem helpItem=new JMenuItem ("幫助(H)");

	//建立工具欄
	JToolBar toolBar = new JToolBar();

	//建立工具欄中的按鈕組件
	JButton portSet;//啟動服務端偵聽
	JButton startServer;//啟動服務端偵聽
	JButton stopServer;//關閉服務端偵聽
	JButton exitButton;//退出按鈕
	
	//框架的大小
	Dimension faceSize = new Dimension(400, 600);
	
	ServerListen listenThread;

	JPanel downPanel ;
	GridBagLayout girdBag;
	GridBagConstraints girdBagCon;


	/**
	 * 服務端構造函數
	 */
	public ChatServer(){
		init();//初始化程序

		//添加框架的關閉事件處理
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.pack();
		//設置框架的大小
		this.setSize(faceSize);

		//設置運行時窗口的位置
		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
		this.setLocation( (int) (screenSize.width - faceSize.getWidth()) / 2,
						 (int) (screenSize.height - faceSize.getHeight()) / 2);
		this.setResizable(false);

		this.setTitle("聊天室服務端"); //設置標題

		//程序圖標
		icon = getImage("icon.gif");
		this.setIconImage(icon); //設置程序圖標
		show();

		//為服務菜單欄設置熱鍵'V'
		serviceMenu.setMnemonic('V');

		//為端口設置快捷鍵為ctrl+p
		portItem.setMnemonic ('P'); 
		portItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_P,InputEvent.CTRL_MASK));

		//為啟動服務快捷鍵為ctrl+s
		startItem.setMnemonic ('S'); 
		startItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_S,InputEvent.CTRL_MASK));

		//為端口設置快捷鍵為ctrl+T
		stopItem.setMnemonic ('T'); 
		stopItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_T,InputEvent.CTRL_MASK));

		//為退出設置快捷鍵為ctrl+x
		exitItem.setMnemonic ('X'); 
		exitItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_X,InputEvent.CTRL_MASK));

		//為幫助菜單欄設置熱鍵'H'
		helpMenu.setMnemonic('H');

		//為幫助設置快捷鍵為ctrl+p
		helpItem.setMnemonic ('H'); 
		helpItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_H,InputEvent.CTRL_MASK));

	}
	
	/**
	 * 程序初始化函數
	 */
	public void init(){

		Container contentPane = getContentPane();
		contentPane.setLayout(new BorderLayout());

		//添加菜單欄
		serviceMenu.add (portItem);
		serviceMenu.add (startItem);
		serviceMenu.add (stopItem);
		serviceMenu.add (exitItem);
		jMenuBar.add (serviceMenu); 
		helpMenu.add (helpItem);
		jMenuBar.add (helpMenu); 
		setJMenuBar (jMenuBar);

		//初始化按鈕
		portSet = new JButton("端口設置");
		startServer = new JButton("啟動服務");
		stopServer = new JButton("停止服務" );
		exitButton = new JButton("退出" );
		//將按鈕添加到工具欄
		toolBar.add(portSet);
		toolBar.addSeparator();//添加分隔欄
		toolBar.add(startServer);
		toolBar.add(stopServer);
		toolBar.addSeparator();//添加分隔欄
		toolBar.add(exitButton);
		contentPane.add(toolBar,BorderLayout.NORTH);

		//初始時，令停止服務按鈕不可用
		stopServer.setEnabled(false);
		stopItem .setEnabled(false);

		//為菜單欄添加事件監聽
		portItem.addActionListener(this);
		startItem.addActionListener(this);
		stopItem.addActionListener(this);
		exitItem.addActionListener(this);
		helpItem.addActionListener(this);
		
		//添加按鈕的事件偵聽
		portSet.addActionListener(this);
		startServer.addActionListener(this);
		stopServer.addActionListener(this);
		exitButton.addActionListener(this);
		
		combobox = new JComboBox();
		combobox.insertItemAt("所有人",0);
		combobox.setSelectedIndex(0);
		
		messageShow = new JTextArea();
		messageShow.setEditable(false);
		//添加滾動條
		messageScrollPane = new JScrollPane(messageShow,
			JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
			JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
		messageScrollPane.setPreferredSize(new Dimension(400,400));
		messageScrollPane.revalidate();
		
		showStatus = new JTextField(35);
		showStatus.setEditable(false);
		
		sysMessage = new JTextField(24);
		sysMessage.setEnabled(false);
		sysMessageButton = new JButton();
		sysMessageButton.setText("發送");

		//添加系統消息的事件偵聽
		sysMessage.addActionListener(this);
		sysMessageButton.addActionListener(this);

		sendToLabel = new JLabel("發送至:");
		messageLabel = new JLabel("發送消息:");
		downPanel = new JPanel();
		girdBag = new GridBagLayout();
		downPanel.setLayout(girdBag);

		girdBagCon = new GridBagConstraints();
		girdBagCon.gridx = 0;
		girdBagCon.gridy = 0;
		girdBagCon.gridwidth = 3;
		girdBagCon.gridheight = 2;
		girdBagCon.ipadx = 5;
		girdBagCon.ipady = 5;
		JLabel none = new JLabel("    ");
		girdBag.setConstraints(none,girdBagCon);
		downPanel.add(none);

		girdBagCon = new GridBagConstraints();
		girdBagCon.gridx = 0;
		girdBagCon.gridy = 2;
		girdBagCon.insets = new Insets(1,0,0,0);
		girdBagCon.ipadx = 5;
		girdBagCon.ipady = 5;
		girdBag.setConstraints(sendToLabel,girdBagCon);
		downPanel.add(sendToLabel);

		girdBagCon = new GridBagConstraints();
		girdBagCon.gridx =1;
		girdBagCon.gridy = 2;
		girdBagCon.anchor = GridBagConstraints.LINE_START;
		girdBag.setConstraints(combobox,girdBagCon);
		downPanel.add(combobox);

		girdBagCon = new GridBagConstraints();
		girdBagCon.gridx = 0;
		girdBagCon.gridy = 3;
		girdBag.setConstraints(messageLabel,girdBagCon);
		downPanel.add(messageLabel);

		girdBagCon = new GridBagConstraints();
		girdBagCon.gridx = 1;
		girdBagCon.gridy = 3;
		girdBag.setConstraints(sysMessage,girdBagCon);
		downPanel.add(sysMessage);

		girdBagCon = new GridBagConstraints();
		girdBagCon.gridx = 2;
		girdBagCon.gridy = 3;
		girdBag.setConstraints(sysMessageButton,girdBagCon);
		downPanel.add(sysMessageButton);

		girdBagCon = new GridBagConstraints();
		girdBagCon.gridx = 0;
		girdBagCon.gridy = 4;
		girdBagCon.gridwidth = 3;
		girdBag.setConstraints(showStatus,girdBagCon);
		downPanel.add(showStatus);

		contentPane.add(messageScrollPane,BorderLayout.CENTER);
		contentPane.add(downPanel,BorderLayout.SOUTH);
		
		//關閉程序時的操作
		this.addWindowListener(
			new WindowAdapter(){
				public void windowClosing(WindowEvent e){
					stopService();
					System.exit(0);
				}
			}
		);
	}

	/**
	 * 事件處理
	 */
	public void actionPerformed(ActionEvent e) {
		Object obj = e.getSource();
		if (obj == startServer || obj == startItem) { //啟動服務端
			startService();
		}
		else if (obj == stopServer || obj == stopItem) { //停止服務端
			int j=JOptionPane.showConfirmDialog(
				this,"真的停止服務嗎?","停止服務",
				JOptionPane.YES_OPTION,JOptionPane.QUESTION_MESSAGE);
			
			if (j == JOptionPane.YES_OPTION){
				stopService();
			}
		}
		else if (obj == portSet || obj == portItem) { //端口設置
			//調出端口設置的對話框
			PortConf portConf = new PortConf(this);
			portConf.show();
		}
		else if (obj == exitButton || obj == exitItem) { //退出程序
			int j=JOptionPane.showConfirmDialog(
				this,"真的要退出嗎?","退出",
				JOptionPane.YES_OPTION,JOptionPane.QUESTION_MESSAGE);
			
			if (j == JOptionPane.YES_OPTION){
				stopService();
				System.exit(0);
			}
		}
		else if (obj == helpItem) { //菜單欄中的幫助
			//調出幫助對話框
			Help helpDialog = new Help(this);
			helpDialog.show();
		}
		else if (obj == sysMessage || obj == sysMessageButton) { //發送系統消息
			sendSystemMessage();
		}
	}
	
	/**
	 * 啟動服務端
	 */
	public void startService(){
		try{
			serverSocket = new ServerSocket(port,10);
			messageShow.append("服務端已經啟動，在"+port+"端口偵聽...\n");
			
			startServer.setEnabled(false);
			startItem.setEnabled(false);
			portSet.setEnabled(false);
			portItem.setEnabled(false);

			stopServer .setEnabled(true);
			stopItem .setEnabled(true);
			sysMessage.setEnabled(true);
		}
		catch (Exception e){
			//System.out.println(e);
		}
		userLinkList = new UserLinkList();
		
		listenThread = new ServerListen(serverSocket,combobox,
			messageShow,showStatus,userLinkList);
		listenThread.start();
	}
	
	/**
	 * 關閉服務端
	 */
	public void stopService(){
		try{
			//向所有人發送服務器關閉的消息
			sendStopToAll();
			listenThread.isStop = true;
			serverSocket.close();
			
			int count = userLinkList.getCount();
			
			int i =0;
			while( i < count){
				Node node = userLinkList.findUser(i);
				
				node.input .close();
				node.output.close();
				node.socket.close();
				
				i ++;
			}

			stopServer .setEnabled(false);
			stopItem .setEnabled(false);
			startServer.setEnabled(true);
			startItem.setEnabled(true);
			portSet.setEnabled(true);
			portItem.setEnabled(true);
			sysMessage.setEnabled(false);

			messageShow.append("服務端已經關閉\n");

			combobox.removeAllItems();
			combobox.addItem("所有人");
		}
		catch(Exception e){
			//System.out.println(e);
		}
	}
	
	/**
	 * 向所有人發送服務器關閉的消息
	 */
	public void sendStopToAll(){
		int count = userLinkList.getCount();
		
		int i = 0;
		while(i < count){
			Node node = userLinkList.findUser(i);
			if(node == null) {
				i ++;
				continue;
			}
			
			try{
				node.output.writeObject("服務關閉");
				node.output.flush();
			}
			catch (Exception e){
				//System.out.println("$$$"+e);
			}
			
			i++;
		}
	}
	
	/**
	 * 向所有人發送消息
	 */
	public void sendMsgToAll(String msg){
		int count = userLinkList.getCount();//用戶總數
		
		int i = 0;
		while(i < count){
			Node node = userLinkList.findUser(i);
			if(node == null) {
				i ++;
				continue;
			}
			
			try{
				node.output.writeObject("系統信息");
				node.output.flush();
				node.output.writeObject(msg);
				node.output.flush();
			}
			catch (Exception e){
				//System.out.println("@@@"+e);
			}
			
			i++;
		}

		sysMessage.setText("");
	}

	/**
	 * 向客戶端用戶發送消息
	 */
	public void sendSystemMessage(){
		String toSomebody = combobox.getSelectedItem().toString();
		String message = sysMessage.getText() + "\n";
		
		messageShow.append(message);
		
		//向所有人發送消息
		if(toSomebody.equalsIgnoreCase("所有人")){
			sendMsgToAll(message);
		}
		else{
			//向某個用戶發送消息
			Node node = userLinkList.findUser(toSomebody);
			
			try{
				node.output.writeObject("系統信息");
				node.output.flush();
				node.output.writeObject(message);
				node.output.flush();
			}
			catch(Exception e){
				//System.out.println("!!!"+e);
			}
			sysMessage.setText("");//將發送消息欄的消息清空
		}
	}

	/**
	 * 通過給定的文件名獲得圖像
	 */
	Image getImage(String filename) {
		URLClassLoader urlLoader = (URLClassLoader)this.getClass().
			getClassLoader();
		URL url = null;
		Image image = null;
		url = urlLoader.findResource(filename);
		image = Toolkit.getDefaultToolkit().getImage(url);
		MediaTracker mediatracker = new MediaTracker(this);
		try {
			mediatracker.addImage(image, 0);
			mediatracker.waitForID(0);
		}
		catch (InterruptedException _ex) {
			image = null;
		}
		if (mediatracker.isErrorID(0)) {
			image = null;
		}

		return image;
	}

	public static void main(String[] args) {
		ChatServer app = new ChatServer();
	}
}