import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import com.objectspace.jgl.*;

public class MDChatServlet extends HttpServlet {
//Initialize global variables
  HashMap messageRepository;
  String user,message,invitemes;
  MDChatUserRepository usernames;
  static int count;
  String randid="";
  String userid="";
  String userarray[]=new String[50];
  java.sql.Connection connect;
  java.sql.Statement st;
  java.sql.ResultSet rs;
//Thread to clean the messageRepository
  RepositoryCleanerThread repCleaner;

  public void init(ServletConfig config) throws ServletException {
    super.init(config);
    try
    {
//      Properties props = getProperties();
      Class.forName("postgresql.Driver");
//      connect=java.sql.DriverManager.getConnection((String)props.get("DBConURL"), (String)props.get("UName"), (String)props.get("PWord"));
      connect=java.sql.DriverManager.getConnection("jdbc:postgresql://192.165.1.4/mdm", "postgres", "postgres");
//      Class.forName("oracle.jdbc.driver.OracleDriver");
//      connect=java.sql.DriverManager.getConnection("jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(PORT=1521)(HOST=128.12.12.70)))(CONNECT_DATA=(SID=ORCL)))", "mdm", "mdm");
      System.out.println("Chat Servlet: Established connection");
      st=connect.createStatement();
    }catch (Exception e){
        e.printStackTrace();
    }
    usernames = MDChatUserRepository.getInstance();
    messageRepository = new HashMap(true);

    RepositoryCleanerThread repCleaner = new RepositoryCleanerThread();
    repCleaner.setPriority(Thread.MIN_PRIORITY);
    repCleaner.setDaemon(true);
    repCleaner.start();
  }

//Process the HTTP Get request

  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//This will be used to pick the messages
    String mode = request.getParameter("mode");
    if(mode.equalsIgnoreCase("get")){
      ObjectOutputStream oos = new ObjectOutputStream(response.getOutputStream());
      try{
        Vector result = new Vector();
        String userName = request.getParameter("userName");
        String randid = request.getParameter("randid");
        Hashtable uservec = (Hashtable)usernames.get(randid);
        if(uservec != null){
          uservec.put(userName, new Long(System.currentTimeMillis()));
        }
System.out.println("MDChatServ: get: "+ userName + messageRepository);
        Enumeration e = messageRepository.values(userName);
        messageRepository.remove(userName);
        while(e.hasMoreElements()){
          result.addElement((String)e.nextElement());
        }
        oos.writeObject(result);
System.out.println("MDChatServ: get result: "+ userName + result);
        result = null;
        e = null;
      }
      catch(Exception ex){
        ex.printStackTrace();
      }
      finally{
        oos.close();
      }
    }
    else if(mode.equalsIgnoreCase("post")){
//Process the post messages here
//This will be used to put messages in hashmap
      try{
        String sub="";
        message = request.getParameter("message");
System.out.println("Chat servlet inside post " + message);
        if (message != null){
//This is a normal chat message
          if (message.charAt(0)=='$')
          {
            try
            {
              randid=message.substring(1,message.indexOf("*"));
              addMessageToRepository(message);
            }
            catch(Exception e){
              e.printStackTrace();
            }
          }
// Acceptance of the invitation
         else if (message.charAt(0)=='^')
          {
            int ind=message.indexOf("*");
            randid=(message.substring(1,ind)).trim();
            userid=(message.substring(ind+1,message.length())).trim();
System.out.println("User accepted "+userid);
System.out.println("Randid accepted "+randid);
            Hashtable uservec = (Hashtable)usernames.get(randid);
System.out.println("Taking the uservec success");
            message="#"+randid+"*";
System.out.println("MD Chat befor accept : " + uservec);
            if(uservec != null){
              uservec.put(userid, new Long(System.currentTimeMillis()));
System.out.println("MD Chat after accept : " + uservec);
System.out.println("Putting the uservec success");
              Enumeration enum = uservec.keys();
              while (enum.hasMoreElements()){
                message+=(String)enum.nextElement() + "*";
              }
              addMessageToRepository(message);
            }
          }
//Removing the user because of log off
          else if (message.charAt(0)=='~')
          {
            int ind=message.indexOf("*");
            randid=message.substring(1,ind);
            userid=message.substring(ind+2,message.length());
            Hashtable uservec = (Hashtable)usernames.get(randid);
System.out.println("usernames: " + usernames);
System.out.println("Before remove: " + uservec);
            messageRepository.remove(userid);
            if(uservec != null){
              uservec.remove(userid);
System.out.println("After remove: " + uservec);
//Since this user has logged off, his
//messages should be removed from the repository
              if (uservec.isEmpty())
              {
                usernames.remove(randid);
              }
              else{
                addMessageToRepository(message);
              }
            }
          }
//This message is for rejection of invitation
          else if (message.charAt(0)=='|')
          {
            int ind=message.indexOf("*");
            randid=message.substring(1,ind);
            String invitorName = randid.substring(0, randid.indexOf("&"));
            userid=message.substring(ind+1,message.length());
System.out.println("Inside reject button "+randid+userid);
            connectToDB();
            addMessageToRepositoryForUser(message, invitorName);
          }
//This message is for user busy
          else if (message.charAt(0)=='@')
          {
            randid=message.substring(1,message.indexOf("*"));
            addMessageToRepositoryForUser(message, randid);
          }
//put the message into repository
          response.setStatus(response.SC_NO_CONTENT);
        }
      }
      catch(Exception ex){
        ex.printStackTrace();
      }
//..........end of post............
    }
  }

//This method will add this message to the repository
//It adds this message for each user
  private void addMessageToRepository(String p_message){
    Hashtable uservec = (Hashtable)usernames.get(randid);
    if(uservec != null){
      Enumeration e = uservec.keys();
System.out.println("adding message " + p_message + " for users " + uservec);
      while(e.hasMoreElements()){
        messageRepository.add((String)e.nextElement(), message);
      }
    }
  }

  private void addMessageToRepositoryForUser(String p_message, String user){
    messageRepository.add(user, message);
  }
//This method is required to set the warning level
//in case of rejection
  public void connectToDB()
  {
    try
    {
      String invitorName = randid.substring(0, randid.indexOf("&"));
      String getrecord="select warning_level from t_chat_user_buddy where user_id='" + invitorName + "' and buddy_id='"+userid+"'";
      rs=st.executeQuery(getrecord);
      System.out.println("after result set");
      if (rs.next())
      {
        int warnlevel=rs.getInt(1)+10;
        if (warnlevel>=100)
        {
          String newtab="insert into t_block_users (user_id, buddy_id) values('" + invitorName + "','"+userid+"')";
          String delrow="delete from t_chat_user_buddy where user_id='" + invitorName + "' and buddy_id='"+userid+"'";
          int blackup=st.executeUpdate(newtab);
          int buddyup=st.executeUpdate(delrow);
        }
      String updaterecord="update t_chat_user_buddy set warning_level=" + warnlevel + " where user_id='" + invitorName + "' and buddy_id='"+userid+"'";
      int en=st.executeUpdate(updaterecord);
      }
      else
      {
        String addrecord="insert into t_chat_user_buddy (user_id, buddy_id, warning_level) values('" + invitorName + "','"+userid+"',"+"'10')";
        int en=st.executeUpdate(addrecord);
      }
      st.close();
      rs.close();
    }
    catch(Exception e)
    {
      System.out.println(e.getMessage());
    }
  }

//Servlet destroy method
  public void destroy(){
    try{
      messageRepository = null;
      connect.close();
      connect = null;
      st = null;
      rs = null;
//Thread to clean the messageRepository
      repCleaner.stopThread();
    }
    catch(Exception ex){
      ex.printStackTrace();
    }
  }

//Get Servlet information

  public String getServletInfo() {
    return "MDMChatServlet Information";
  }

  private Properties getProperties(){
    boolean found = true;
		Properties props=null;
    ObjectInputStream oin=null;
    FileInputStream in=null;
		try{
  		in=new FileInputStream("DBProperties.props");
		}
		catch(FileNotFoundException ex){
	  	System.out.println("File not found "+ ex.getMessage());
      try{
        in.close();
      }
      catch(Exception subEx){
        subEx.printStackTrace();
      }
      found = false;
		}
		catch(SecurityException ex){System.out.println("Security exception-I "+ex.getMessage());}
 		if(found){
  		try{
	    	oin=new ObjectInputStream(in);
 			}
 			catch(StreamCorruptedException ex){
        System.out.println("StreamCorruptedException-I "+ex.getMessage());
      }
      catch(IOException ex){
        System.out.println("IOException-I "+ex.getMessage());
      }
      try{
        props=(Properties)oin.readObject();
      }
      catch(ClassNotFoundException ex){
        System.out.println("ClassNotFoundException "+ex.getMessage());
      }
      catch(InvalidClassException ex){
        System.out.println("InvalidClassException "+ex.getMessage());
      }
      catch(StreamCorruptedException ex){
        System.out.println("StreamCorruptedException-II "+ex.getMessage());
      }
      catch(OptionalDataException ex){
        System.out.println("OPtionalDataException "+ex.getMessage());
      }
      catch(IOException ex){
        System.out.println("IOException-II "+ex.getMessage());
      }
 		}
    try{
      oin.close();
    }
    catch(Exception ex){
      ex.printStackTrace();
    }
		return props;
  }

  class RepositoryCleanerThread extends Thread{
    private boolean isStopPending = false;

    RepositoryCleanerThread(){
      super();
    }

    public void stopThread(){
      isStopPending = true;
    }

    public void run(){
      while (!isStopPending){
//Go through all the users in order to confirm that
//all users have been continuously accessing their
//messages. In case this is not happening perform:
//1. remove messages from repository
//2. add remove message for the other users with this randid
//3. remove user from usernames
        Enumeration randids = usernames.keys();
        while(randids.hasMoreElements()){
          String tempRandid = (String)randids.nextElement();
          Hashtable uservec = (Hashtable)usernames.get(tempRandid);
          if(uservec == null){
            usernames.remove(tempRandid);
          }
          else{
            Enumeration chatRoomUsers = uservec.keys();
            while(chatRoomUsers.hasMoreElements()){
              String chatRoomUser = (String)chatRoomUsers.nextElement();
              Long lastTimeAccessed = (Long)uservec.get(chatRoomUser);
              if((System.currentTimeMillis() - lastTimeAccessed.longValue()) > 100000){
System.out.println("Removing user: " + chatRoomUser + " from chat session.");
                uservec.remove(chatRoomUser);
                messageRepository.remove(chatRoomUser);
              }
            }
          }
        }
        try{
          sleep(20000);
        }
        catch(Exception ex){
          ex.printStackTrace();
        }
      }
    }

    private void sendRemoveUserMessage(String randid){
    
    }
  }
}