server.py

import socket
import sys
import argparse
import select
import re

clients = {}
active_clients = []

def parse_input():
    parser = argparse.ArgumentParser(description="Chat server program")

    parser.add_argument("--port", required=True, help="server port")

    args = parser.parse_args()

    if len(sys.argv) < 2:
        print("Usage: python3 p2-sptjohns-erwalee-server.py --port <port>")
        sys.exit(1)

    # test args here
    try:
        args.port = int(args.port)
    except ValueError:
        print("Error: arguments incorrect")
        exit(1)

    return args
    

def register_user(lines, s_ip, s_port, c_socket):       
    nothing, nothing, c_id = str(lines[1]).partition(":")      # reading message
    c_id = c_id.strip()
    nothing, nothing, c_ip = str(lines[2]).partition(":")
    c_ip = c_ip.strip()
    nothing, nothing, c_port = str(lines[3]).partition(":")
    c_port = c_port.strip()
    clients[c_id] = f"{c_ip}:{c_port}"                        # parsing message

    print(f"REGISTER: {c_id} from {c_ip}:{c_port} received")

    # sending REGACK
    msg = f"REGACK\r\nclientID: {c_id}\r\nIP: {s_ip}\r\nPort: {s_port}\r\nStatus: registered\r\n\r\n"
    c_socket.send(msg.encode())


def bridge_user(lines, c_socket):
    # reading message sent
    nothing, nothing, c_id = str(lines[1]).partition(":")       
    c_id = c_id.strip()

    active_clients.append(c_id)                     # adding to the list of active clients

    # if one client, send empty bridgeack, if multiple bridge incoming with exisiting
    if (len(active_clients) == 1):                  
        print(f"BRIDGE: {c_id} {clients[c_id].partition(':')[0]}:{clients[c_id].partition(':')[2]}")
        msg = f"BRIDGEACK\r\nclientID: \r\nIP: \r\nPort: \r\n\r\n"
        c_socket.send(msg.encode())
    elif (len(clients) > 1):                        
        print(f"BRIDGE: {active_clients[0]} {clients[active_clients[0]].partition(':')[0]}:{clients[active_clients[0]].partition(':')[2]} {c_id} {clients[c_id].partition(':')[0]}:{clients[c_id].partition(':')[2]}")
        msg = f"BRIDGEACK\r\nclientID: {active_clients[0]}\r\nIP: {clients[active_clients[0]].partition(':')[0]}\r\nPort: {clients[active_clients[0]].partition(':')[2]}\r\n\r\n"
        c_socket.send(msg.encode())




def main():
    args = parse_input()
    s_port = args.port
    s_ip = "127.0.0.1"

    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    # make sure this ip is correct
    s.bind((s_ip, s_port))

    data = s.getsockname()
    print(f">Server running on {data[0]}:{data[1]}")

    s.listen()

    while(True):
        ready_to_read, _, _ = select.select([s, sys.stdin], [], [], 1.0)

        for sock in ready_to_read:
            if sock is s:
                (c_socket, c_ip) = s.accept()           # accepting connections
                c_data = c_socket.recv(1024)            # reading data
                #print(c_data.decode())
                c_data = c_data.decode()
                #print(c_data)
                lines = c_data.splitlines()             # splitting message
                #print(lines)

                if (lines[0] == 'REGISTER'):            # choosing register or bridge
                    register_user(lines, s_ip, s_port, c_socket)
                elif (lines[0] == 'BRIDGE'):
                    bridge_user(lines, c_socket)
                else:
                    print("Malformed incoming message", file=sys.stderr) # fix to stderr 
                    # need to properly close silly goose
                    c_socket.close()
                    s.close()
                    sys.exit(1) # better for exiting bc of error
                c_data = None 
            elif sock is sys.stdin:
                user_input = sys.stdin.readline().strip()       # getting user input
                if (user_input == "/info"):
                    for client in clients.keys():
                        print(f"{client} {clients[client]}")


if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        print("\nTerminating server")
        exit()