#!/usr/bin/env python3
from socket import *
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)
print(our_socket)

while True:
    client_socket, client_address = our_socket.accept()
    print("We got a new connection from:  ", client_address[0], client_address[1])
    # First, get a math problem from the client
    # Protocol:  Client sends two 4-byte signed integers in network byte order, 8 bytes total
    while True:
        try:
            data = client_socket.recv(8, MSG_WAITALL) # We'll get 8 bytes
            a, b = unpack("!ii", data)
        except:
            print("Something is wrong with that client")
            break

        print("We got a = ", a, " b = ", b)
    
        # Then figure out the answer
        c = a + b
    
        # Then send the result
        data_to_send = pack("!i", c)
        client_socket.send(data_to_send)

    client_socket.close()

our_socket.close()