server.py

import argparse
import socket
from datetime import datetime

HOST = "127.0.0.1"
PORT = 8080
NUM_CONNS = 5
DEFAULT_RESPONSE = b"Request received!"


def construct_response(response_payload: bytes = DEFAULT_RESPONSE) -> bytes:
    response_line = b"HTTP/1.1 200 OK\r\n"
    headers = b"".join(
        [b"Server: CrappyServer/0.0.1\r\n", b"Content-Type: text/plain\r\n"]
    )
    blank_line = b"\r\n"

    response = b"".join([response_line, headers, blank_line, response_payload])

    return response


def start_server(
    response: bytes, host: str = HOST, port: int = PORT
) -> tuple[str, str]:
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    s.bind((host, port))
    s.listen(NUM_CONNS)
    print("Server_listening at:", s.getsockname())

    while True:
        conn, addr = s.accept()
        data = conn.recv(1024)

        if not data:
            break

        print(f"\n[{datetime.now()}]")
        print("Server_new_connection_from:", addr)
        print("Server_request:\n", data.decode("utf-8"))
        print("\nServer_response:\n", response.decode("utf-8"))

        conn.sendall(response)
        conn.close()

    return response.decode("utf-8"), data.decode("utf-8")


def main() -> None:
    parser = argparse.ArgumentParser(
        description="HTTP Server with configurable response"
    )
    parser.add_argument(
        "-p",
        "--response-payload",
        dest="response_payload",
        type=str,
        default=DEFAULT_RESPONSE,
        help="Custom response payload in plaintext (default: 'Request received!')",
    )
    args = parser.parse_args()

    start_server(response=construct_response(args.response_payload.encode("utf-8")))


if __name__ == "__main__":
    print("Starting standalone server...")
    main()