#!/usr/bin/env python3
from socket import *
from _thread import start_new_thread
from struct import pack, unpack

# Create a socket.  This doesn't open a port or anything yet
# Parameters:
#   AF_INET is ipv4, AF_INET6
#   SOCK_STREAM means TCP, SOCK_DGRAM would be UDP
our_socket = socket(AF_INET, SOCK_STREAM)
# Bind is only for servers, not client 
# clients call connect instead
# Still doesn't open it, although we have an address
# Double parenthesis = 1 argument which is a tuple
our_socket.bind(("0.0.0.0", 5111))

# Actually opens the port
# Argument is a queue of connections to accept
our_socket.listen(5)
    
def handle_client(client_socket):
    while True:
        try:
            data = client_socket.recv(9, MSG_WAITALL) # We'll get 8 bytes
            op, a, b = unpack("!Bii", data)
            if(op == ord('+')):
                c = a + b
            elif(op == ord('*')):
                c = a * b
            elif(op == 0):
                print("Client gracefully disconnected")
                break
        
            # Then send the result
            data_to_send = pack("!i", c)
            client_socket.send(data_to_send)
    
        except:
            print("Something is wrong with that client")
            break
    client_socket.close()

while True:
    client_socket, client_address = our_socket.accept()
    print("We got a new connection from:  ", client_address[0], client_address[1])
    start_new_thread(handle_client, (client_socket, ))

our_socket.close()