package Server;

import java.io.IOException;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;


public class Server {

	//handle singleton
	private static Server myInstance = new Server();

	public static Server getInstance() {
		return myInstance;
	}

	//private constructor
	private Server() {
		userMap = new HashMap<String, String>();
		lastSeen = new HashMap<String,String>();
		user2Ip = new HashMap<String,String>();
	}


	private static void usage(){
		System.err.println("Nap use this: ./server tcpport udpport where port is an int from 12400-12500");
		System.exit(1);
	}

	private static void checkPorts(){

		if( (tcpPort<12400 || tcpPort>12500) || (udpPort<12400 || udpPort>12500) )
			usage();
	}

	/**
	 * returns 0 if user successfuly logged in
	 * returns 1 if user is not known
	 * returns 2 if username and password do not match
	 */
	public static int logonUser(String _username,String _password, String _ipAdress)
	{
	    boolean hasKey = userMap.containsKey(_username);
	    if(!hasKey)
	    	return 1;
	    String pw4User = userMap.get(_username);
	    if(pw4User.equals(_password))
	    {
	    	//Do logon stuff here
	    	//boolean hasKeyLS = lastSeen.containsKey(_username);
	    	//if(!hasKeyLS){
	    	    // when user logs on or off
	    	    java.util.Date now = new Date(System.currentTimeMillis());
	    	    java.text.DateFormat formatter = new java.text.SimpleDateFormat("dd.MM.yyyy HH:mm");
	    	    String result = formatter.format(now); // e.g. result == "10.09.2009 17:44"
	    	    String loggedOn = "1:"+result;
	    		lastSeen.put(_username, loggedOn);
	    		user2Ip.put(_username, _ipAdress);
	    	//}else{

	    	//}
	    	return 0;
	    }
	    return 2;
	}

	public static void logoffUser(String _username)
	{
	    java.util.Date now = new Date(System.currentTimeMillis());
	    java.text.DateFormat formatter = new java.text.SimpleDateFormat("dd.MM.yyyy HH:mm");
	    String result = formatter.format(now); // e.g. result == "10.09.2009 17:44"
	    String loggedOff = "0:"+result;
		lastSeen.put(_username, loggedOff);
	}

	public static String getUserInfo(String _username)
	{
		boolean hasKey = lastSeen.containsKey(_username);
	    if(!hasKey)
	    	return "2:never logged on";

		//returns the userstatus
		return lastSeen.get(_username);
	}

	/**
	 * @param args
	 * [TcpPort] Tcp Port on which the server should listen
	 * [UdpPort] Udp Port on which the server should listen
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub

		if(args.length != 2)
			usage();
		//check if the 2 port arguments are integers
	    try {
	    	tcpPort = Integer.parseInt(args[0]);
	    	udpPort = Integer.parseInt(args[1]);
	    } catch (NumberFormatException e) {
	        System.err.println("Arguments must be an integer");
	        System.exit(1);
	    }

	    //print usage message and exit if ports are not valid
	    checkPorts();

	    java.io.InputStream in = ClassLoader.getSystemResourceAsStream("users.properties");
	    if (in != null) {

		    java.util.Properties users = new java.util.Properties();
		    try{
		    	users.load(in);
		    }catch(IOException e){

		    }
		    java.util.Set<String> usernames = users.stringPropertyNames(); // get all usernames

		    for (String username : usernames) {
		    	String password = users.getProperty(username); // get password for user with username
		    	//fil map with users from config file
		    	userMap.put(username, password);
		    }
	    }else{
	    	System.err.println("The required file users.properties was not found.");
	    	System.exit(1);
	    }

	    Set<Entry<String, String>> s = userMap.entrySet();
	    Iterator<Entry<String, String>> it = s.iterator();

	    while(it.hasNext())
        {
            // key=value separator this by Map.Entry to get key and value
            Map.Entry<String, String> m =(Map.Entry<String, String>)it.next();

            // getKey is used to get key of Map
            String key=(String)m.getKey();

            // getValue is used to get value of key in Map
            String value=(String)m.getValue();

            System.out.println("Key :"+key+"  Value :"+value);
        }
	    System.out.println("logging on user john returns: "+logonUser("john", "12345", "192.168.0.1:12000"));
	    System.out.println("userinfo for john: "+getUserInfo("john"));



	}

	//Map<username, password>
	Map<String,String> userMap;
	//Map<username, loggedOn[0||1]:timestamp>
	Map<String,String> lastSeen;
	//Map<username, ip:port>
	Map<String,String> user2Ip;
	int tcpPort, udpPort;



}