import argparse
import serial
import threading
import time
import websocket

kDefaultSerialPort = None
kDefaultBaudrate = 115200


def getserial(port=None, baudrate=None, **kwargs):
    if port is not None:
        return serial.Serial(port, baudrate)

    # return first /dev/ttyACMx found
    for i in range(10):
        try:
            return serial.Serial(f"/dev/ttyACM{i}", baudrate)
        except serial.SerialException:
            pass
    raise RuntimeError("No serial device available.")


def parse_args():
    parser = argparse.ArgumentParser(description="Bridge a serial port to a websocket")
    parser.add_argument(
        "--port", help="path to the serial port", default=kDefaultSerialPort
    )
    parser.add_argument("--baudrate", default=kDefaultBaudrate)
    parser.add_argument("ws", help="URL of the websocket")
    return parser.parse_args()


def device_thread(device, ws):
    while True:
        line = device.readline()
        ws.send(line)


def slowwrite(device, data):
    for b in data:
        device.write([b])
        time.sleep(0.005)


def ws_thread(device, ws):
    while True:
        data = ws.recv()
        slowwrite(device, data.replace(b"\n", b"\r\n"))


def main():
    args = parse_args()
    device = getserial(**vars(args))
    ws = websocket.create_connection(args.ws)

    wst = threading.Thread(target=ws_thread, args=(device, ws), daemon=True)
    wst.start()

    device_thread(device, ws)


if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        pass