#!/usr/bin/env python3
"""TFTP + BOOTP server for the dwt/tcpip fetch experiment.

Serves ``dwt/tcpip/probe.bin`` for *any* requested name (the terminal's TFTP
client asks for the exact filename we put in the payload) and logs every RRQ.
``--bootp`` reuses the L2 BOOTP responder from ``harness/serve.py`` so the
terminal learns 192.168.99.2 at power-up; that file is imported, not modified.

    sudo python3 -u dwt/tcpip/serve_probe.py 192.168.99.1 --bootp

Run this instead of ``harness/serve.py`` when the file to serve is the probe:
both want UDP 69, so only one can be up.
"""
import argparse
import os
import sys
import time

HERE = os.path.dirname(os.path.abspath(__file__))
ROOT = os.path.dirname(os.path.dirname(HERE))
sys.path.insert(0, os.path.join(ROOT, "tools"))
sys.path.insert(0, os.path.join(ROOT, "harness"))

import fontgen  # noqa: E402
import serve as hserve  # noqa: E402

PROBE = os.path.join(HERE, "probe.bin")


def main(argv=None):
    ap = argparse.ArgumentParser(description=__doc__,
                                 formatter_class=argparse.RawDescriptionHelpFormatter)
    ap.add_argument("host", nargs="?", default="192.168.99.1")
    ap.add_argument("port", nargs="?", type=int, default=69)
    ap.add_argument("--bootp", action="store_true")
    ap.add_argument("--bootp-client", default="192.168.99.2")
    ap.add_argument("--bootp-iface", default=None)
    ap.add_argument("--file", default=PROBE)
    args = ap.parse_args(argv)

    content = open(args.file, "rb").read()
    # Answer any name with the probe: the payload chooses the name, and the
    # log records exactly what the terminal asked for.
    srv = fontgen.TFTPServer((args.host, args.port), {}, timeout=60.0,
                             retries=10, resolver=lambda name: content).start()
    print(f"tftp: serving {len(content)} bytes ({os.path.basename(args.file)}) "
          f"for any name on {srv.address}", flush=True)

    bootp = None
    if args.bootp:
        bootp = hserve.BootpResponder(server_ip=args.host,
                                      client_ip=args.bootp_client,
                                      iface=args.bootp_iface).start()
        print(f"bootp: L2 responder on {bootp.iface}: handing out "
              f"{bootp.client_ip}, siaddr {bootp.server_ip}", flush=True)

    start = time.time()
    try:
        while True:
            time.sleep(0.2)
            while srv.log:
                ts, name, addr = srv.log.pop(0)
                stamp = time.strftime("%H:%M:%S", time.localtime(ts))
                print(f"{stamp}  RRQ {addr[0]}:{addr[1]} requested {name!r} "
                      f"({content.__len__()} bytes)", flush=True)
    except KeyboardInterrupt:
        pass
    finally:
        srv.stop()
        if bootp:
            bootp.stop()


if __name__ == "__main__":
    main()