// 程序：多人連線服務器
// 范例文件：ServerFrame.java

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

public class ServerFrame extends Frame implements ActionListener
{
   int      ScreenWidth,ScreenHeight; 
   Button   CloseServer;
   TextArea ServerStatus;
   
   ServerThread sThread;

   public ServerFrame()    
   {
      super("游戲服務器");   
      
      ServerStatus = new TextArea();   
      CloseServer  = new Button("關閉服務器"); 
      ServerStatus.setEditable(false);  
      CloseServer.addActionListener(this); 

      add(ServerStatus,BorderLayout.CENTER);  
      add(CloseServer,BorderLayout.SOUTH); 

      ScreenWidth  = getToolkit().getScreenSize().width;
      ScreenHeight = getToolkit().getScreenSize().height;
      setSize(ScreenWidth / 2,ScreenHeight / 2);
      setLocation((ScreenWidth - getWidth()) / 2,
                  (ScreenHeight - getHeight()) / 2);
      
      setResizable(false);  
      setVisible(true);   

      sThread      = new ServerThread(this); 
      sThread.start();  
   }

   public static void main(String srgs[])
   {
      new ServerFrame();    
   }

   public void actionPerformed(ActionEvent e) 
   {
      dispose();
      System.exit(0);    
   }
}

class ServerThread extends Thread 
{
   int          sPort;     
   ServerSocket sSocket;    
   ServerFrame  frame;

   TextArea     sStatus;

   Vector       Clients;   
   Vector       messages;   

   BroadCast        BroadCastWriter;  
   CleanDeadConnect Cleaner;   

   public ServerThread(ServerFrame f)
   {
      Clients  = new Vector();  
      messages = new Vector();

      try
      {
         sPort   = 6633;    
         sSocket = new ServerSocket(sPort); 
      }
      catch(IOException E)     
      {
         System.out.println("發生例外: " + E);
         System.out.println("無法建立服務器端口!!");
         System.exit(1);  
      }

      this.frame = f;
      sStatus    = frame.ServerStatus;
 
      sStatus.append("游戲服務器已啟動..\n\n");
      sStatus.append(">>>>>等待連線<<<<<\n\n");

      BroadCastWriter = new BroadCast(this); 
      BroadCastWriter.start();   

      Cleaner = new CleanDeadConnect(this);  
      Cleaner.start();      
   }

   public void run()
   {
      while(true)       
      {
         try
         {
            Socket cSocket       = sSocket.accept(); 

            ClientThread cThread = new ClientThread(cSocket,this);
            cThread.start();    

            sStatus.append(cThread.getClientName() + ":");
            sStatus.append(cThread.getClientAddress() + "已連線 ");
            sStatus.append("目前連線數: " + ClientThread.ConnectNumber +
                           "\n");

            synchronized(Clients)   
            {
               Clients.addElement(cThread); 
            }
         }
         catch(IOException E)    
         {
            System.out.println("發生例外: " + E);
            System.out.println("建立客戶端連線失敗!");
            System.exit(2);    
         }
      }
   }

   public void finalize()
   {
      try
      {
         sSocket.close();   
      }
      catch(IOException E){}
     
      sSocket = null;     
   }
}

class ClientThread extends Thread
{
   Socket          cSocket;   
   PrintStream     write;   
   BufferedReader  read;     
   ServerThread    sThread;

   TextArea        sStatus;
   String          m;

   public static int ConnectNumber = 0; 
   
   public ClientThread(Socket cSocket,ServerThread sThread)
   {
      this.cSocket = cSocket;
      this.sThread = sThread; 

      sStatus      = sThread.frame.ServerStatus;  
 
      ConnectNumber++;   
      
      try
      {

         write = new PrintStream(cSocket.getOutputStream());
         read  = new BufferedReader(
                     new InputStreamReader(cSocket.getInputStream()));
      }
      catch(IOException E)   
      {
         System.out.println("發生例外: " + E);
         System.out.println("建立I/O管道失敗!");
         System.exit(3);  
      }
 
      m = "新伙伴<" + getClientName() + ">加入羅!!! ";
      m = m + "聊天室人數: " + ConnectNumber + " \n\n";
   
      sThread.messages.addElement(m);
   }
  
   public void run()
   {
      while(true)
      {
         try
         {
            String Message = read.readLine();

            synchronized(sThread.messages)  
            {
               if(Message != null)   
               {
                  if(Message.equals("bye")) 
                  {
                     ConnectNumber--; 

                     Message = getClientName() + ":" + getClientAddress() + 
                               "已離開 ";

                     sStatus.append(Message + " ");
                     sStatus.append("目前連線數: " + ConnectNumber + "\n");

                     sThread.messages.addElement(Message);

                     synchronized(sThread.Clients)  
                     {
                        sThread.Clients.removeElement(this); 
                     }

                     break;   
                  }
                  else
                  {
                     Message = "來自" + getClientName() + ":" + 
                               getClientAddress() + "\n=> " + Message + "\n";

                     sThread.messages.addElement(Message);
                  }
               }
            }
         }
         catch(IOException E)  
         { 
            break;       
         }
      }
   }

   public String getClientName()     
   {
      return cSocket.getInetAddress().getHostName();
   }
  
   public String getClientAddress()  
   {
      return cSocket.getInetAddress().getHostAddress(); 
   }

   public void finalize()
   {
      try
      {
         read.close();
         write.close();
         cSocket.close();  
      }
      catch(IOException E){}
     
      cSocket = null;     
   }
}

class BroadCast extends Thread   
{
   ClientThread c;
   ServerThread sThread;
   String       m;

 
   public BroadCast(ServerThread sThread)
   {
      this.sThread    = sThread;
   }

   public void run()
   {
      while(true)
      { 
         try
         {
            Thread.sleep(3000);  
         }
         catch(InterruptedException E){}

         synchronized(sThread.messages)    
         {
            if(sThread.messages.isEmpty())   
               continue;                    
           
            m = (String)sThread.messages.firstElement();
            sThread.messages.removeElement(m); 
         }

         synchronized(sThread.Clients)    
         {

            for(int i=0;i<sThread.Clients.size();i++)
            {
               c = (ClientThread)sThread.Clients.elementAt(i);
               c.write.println(m);
            }
         }
      }
   }
}

class CleanDeadConnect extends Thread 
{
   ServerThread sThread;
   ClientThread temp;
   String       m;

   public CleanDeadConnect(ServerThread sThread)
   {
      this.sThread = sThread;
   }

   public void run()
   {  
      while(true)
      {  
         try
         {
            Thread.sleep(10000);   
         }
         catch(InterruptedException E){}

         synchronized(sThread.Clients) 
         {
            for(int i=0;i<sThread.Clients.size();i++)
            {
               temp = (ClientThread)sThread.Clients.elementAt(i);

               if(!temp.isAlive())    
               {
                  ClientThread.ConnectNumber--; 

                  m = temp.getClientName() + ":" + temp.getClientAddress();
                  m = m + "已離開 目前連線數: " + 
                      ClientThread.ConnectNumber + "\n";

                  sThread.frame.ServerStatus.append(m);
                  
                  synchronized(sThread.messages)   
                  {
                     sThread.messages.addElement(m);
                  }

                  sThread.Clients.removeElementAt(i);
               }   
            }
         }
      }
   }
}