#!/usr/bin/env python3
# cdc.py -- minimal host helper to talk to the c2probe CDC line protocol.
# Uses termios (no pyserial). Usage:
#   ./cdc.py hello
#   ./cdc.py id2
#   ./cdc.py "read 2400 16"
# Sends one command, prints all reply lines until a known terminator/prompt.
import sys, os, termios, tty, time, select

DEV = os.environ.get("C2PROBE_DEV", "/dev/cu.usbmodem2101")

def open_port():
    fd = os.open(DEV, os.O_RDWR | os.O_NOCTTY | os.O_NONBLOCK)
    attrs = termios.tcgetattr(fd)
    attrs[2] = termios.CS8 | termios.CLOCAL | termios.CREAD  # cflag
    attrs[3] = 0                                               # lflag: raw
    attrs[4] = termios.B115200                                 # ispeed
    attrs[5] = termios.B115200                                 # ospeed
    # no flow control, no special chars
    attrs[0] = 0; attrs[1] = 0
    termios.tcsetattr(fd, termios.TCSANOW, attrs)
    return fd

def drain(fd, t=0.15):
    r, _, _ = select.select([fd], [], [], t)
    if r:
        try: return os.read(fd, 4096).decode("utf-8", "replace")
        except BlockingIOError: return ""
    return ""

def cmd(fd, line, timeout=3.0):
    os.write(fd, (line + "\n").encode())
    out = ""
    end = time.time() + timeout
    while time.time() < end:
        r, _, _ = select.select([fd], [], [], 0.1)
        if r:
            try: out += os.read(fd, 4096).decode("utf-8", "replace")
            except BlockingIOError: pass
        # stop once we have at least one complete line and the port goes quiet
        if "\n" in out:
            # give a short quiet window for any trailing lines
            r2, _, _ = select.select([fd], [], [], 0.08)
            if not r2:
                break
    return out

if __name__ == "__main__":
    line = " ".join(sys.argv[1:]) if len(sys.argv) > 1 else "hello"
    fd = open_port()
    drain(fd, 0.3)  # drop any startup/banner
    print(cmd(fd, line), end="")
    os.close(fd)