mport socket

import tkinter
import time
from tkinter import *
from tkinter import font

userpass={"Koncar":"123", "Milica":"321", "Biljana":"222"}
top=tkinter.Tk()
top.geometry("500x400")
font=font.Font(top, family="Verdana", size=12)

Label0=tkinter.Label(top, text="Server side\r\n", font=font)
Label0.pack(side=TOP)

s=socket.socket()
host=socket.gethostname()
port=2222
s.bind((host, port))
s.listen(5)
conn, addr=s.accept()
poruka="Enter username and password:"
conn.send(poruka.encode())

username=conn.recv(20).decode()
password=conn.recv(20).decode()

for usr, pas in userpass.items():
    if username==usr and password==pas:
        Label1=tkinter.Label(top, text="Connected to "+username+" at "+\
                    time.asctime(time.localtime(time.time())), font=font )
        poruka="Hello, "+username
        conn.send(poruka.encode())
        break
else:
    pogresno="Who are you?"
    conn.send(pogresno.encode())
    Label2=tkinter.Label(top, text="Unknown user tried to connect at "+\
                    time.asctime(time.localtime(time.time())), font=font )
    Label2.pack()



top.mainloop()