#!/usr/bin/env python3

import argparse
import sys
import time
import serial

def read_response(port: serial.Serial, timeout_s: float) -> list[str]:
    deadline = time.monotonic() + timeout_s
    lines: list[str] = []

    while time.monotonic() < deadline:
        raw = port.readline()
        if not raw:
            continue

        line = raw.decode(errors="replace").strip()
        if not line:
            continue

        lines.append(line)
        if line in {"OK", "ERROR"}:
            break

    return lines

def send_at(port: serial.Serial, command: str, timeout_s: float) -> tuple[bool, list[str]]:
    port.write((command + "\r").encode())
    port.flush()
    lines = read_response(port, timeout_s)

    ok = any(line == "OK" for line in lines)
    err = any(line == "ERROR" for line in lines)
    return ok and not err, lines

def send_and_log(port: serial.Serial, command: str, timeout_s: float) -> tuple[bool, list[str]]:
    ok, lines = send_at(port, command, timeout_s)
    print(f"> {command}")
    for line in lines:
        print(f"< {line}")
    return ok, lines


def main() -> int:
    parser = argparse.ArgumentParser(description="Control an AT modem and send DTMF tones")
    parser.add_argument("device", help="Serial device path, e.g. /dev/ttyACM0")
    parser.add_argument("--baud", type=int, default=115200, help="Serial baudrate (default: 115200)")
    parser.add_argument("--timeout", type=float, default=2.0, help="AT command timeout seconds")
    args = parser.parse_args()

    try:
        with serial.Serial(args.device, args.baud, timeout=0.2, write_timeout=1.0) as port:
            port.reset_input_buffer()
            port.reset_output_buffer()

            # Inicialise

            for cmd in ("AT", "ATZ0", "ATE1", "ATX0"):
                ok, lines = send_and_log(port, cmd, args.timeout)
                if not ok:
                    print(f"Modem did not accept {cmd}", file=sys.stderr)
                    return 1

            send_and_log(port, "ATS6=0", args.timeout) # Set wait for dial tone time to 0
            send_and_log(port, "ATS11=2", args.timeout) # set tone length to 1 ms
            send_and_log(port, "ATH1", args.timeout)
            while True:
                send_and_log(port, "ATDT0123456789;", args.timeout)
            send_and_log(port, "ATH0", args.timeout)

    except serial.SerialException as exc:
        print(f"Serial error: {exc}", file=sys.stderr)
        return 1

    print("Done")
    return 0

if __name__ == "__main__":
    raise SystemExit(main())