//package server;

import java.sql.*;
import java.sql.DriverManager;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.SQLWarning;
import java.sql.SQLException;
import java.io.IOException;

import java.util.Vector;

// Class User Manager
// Manage All user existants an all controler Mehtod are to Manage correctly 
// The possible Users

public class  CUserManager extends CDataBaseManager
{
	// Singleton controler Property!
	private static CUserManager instance = null;
	private Vector		Users;
	// Singleton Factory for UserManager Class
	public static CUserManager getInstance() {
		if (instance == null) {
			instance = new CUserManager();
		}
		return instance;
	}

	// -------------------------------------------------------------------------------------------
	// I don't wont any one to Extends this class !!! so nobody has the access to Constructor Method
	// -------------------------------------------------------------------------------------------
	private CUserManager(){
		Users = sp_RetrieveAllUsers();
	}
	public synchronized Vector getAllUsers()
	{
		return Users;
	}

	public boolean refreshUserList () {
		Vector newList = sp_RetrieveAllUsers();
		CUser aUser		= null;
		CUser regUser	= null;
		for (int i = 0 ; i < newList.size() ; i++) {
			aUser = (CUser) newList.elementAt(i);
			regUser = getUser(aUser.getId());
			if (regUser == null ) {
				Users.addElement(aUser);
			} else {
				regUser.setName(aUser.getName());
				regUser.setPassword(aUser.getPassword());
			}
		}
		return true;
	};
	
	public synchronized CUser createUser(CUser auser){
		if (sp_insertUser(auser)) {
			refreshUserList();
			return ((CUser)Users.elementAt((Users.size()-1)));
		}
		return null;
	}

	public boolean deleteUser (CUser auser) {
		if (sp_DeleteUser(auser.getId())) {
			for (int i = 0 ; i < Users.size();i++){
				if ( ((CUser)Users.elementAt(i)).getId() == auser.getId()){
					Users.removeElementAt(i);
					return true;
				}
			}
		}
		return false;
	}

	public synchronized boolean updateUser(CUser auser) {
		CUser user = getUser(auser.getId());
		if (user == null) {
			return false;	// this user does not exists
		}
		if (sp_UpdateUser(auser)) {
			user.setName(auser.getName());
			user.setPassword(auser.getPassword());
		}
		return false;
	}
	public CUser getUser(int id) {
		CUser user = null;

		int init, end, mid;	
		init = 0;
		end = Users.size() -1 ;
		mid = (int) end/2;
	
		// THIS WILL ONLY WORK IF THE LIST IS ORGANIZED by ID!!!
		for (int counter =0 ; counter <= Users.size()/2 ; counter ++)
		{
			user = (CUser)Users.elementAt(counter);
			if (user.getId()== id)
				return user;
			else
				if (id < user.getId()) {
					end = mid;
					mid = (int) (end-(init-1))/2 + init;//(int) (end/2) ;
				} else {
					init = mid;
					mid = (int) (end-(init-1))/2 + init;
				}
		}
		return null;
					
		/*
		for (int counter = 0 ; counter < Users.size() ; counter++) {
			aUser = (CUser)Users.elementAt(counter);
			if ( aUser.getId() == id ) {
				return (CUser)Users.elementAt(counter);
			}
		}
		return null;
		*/
	}
	public CUser getUser(String aLogin) {
		for (int counter = 0 ; counter < Users.size() ; counter++) {
			if ( ((CUser)Users.elementAt(counter)).getName().equalsIgnoreCase(aLogin) ) 
				return (CUser)Users.elementAt(counter);
		}
		return null;
	}
	public boolean checkUserAuthentication(int userID, String userPassword ) {
		CUser user = getUser(userID);
		return (user.getPassword().equalsIgnoreCase(userPassword));
	}

	// if the user is ofline this method is invoked
	public boolean saveOfflineMessage(int from,int to, String message) {
		CUser auser = getUser(to);
		if (auser == null) {
			return false;
		}
		if (sp_SaveMessage(from,to, message)) {
			return true;
		}
		return false;
	}

	// needs no comments
	public synchronized boolean isUserOnline (CUser user) {
		return getUser(user.getId()).isUserOnline();
	}
	// needs no comments
	public synchronized boolean isUserOnline (int userId) {
		return getUser(userId).isUserOnline();
	}

	public synchronized boolean isUserExists(int id){
		return ( getUser(id) != null );
	}

	public synchronized Vector getUserFriends(int id) {
		return sp_RetrieveUserFriends(id);
	}
		
}