import time
from machine import UART, Pin


time.sleep(0.1) # Wait for USB to become ready

WAIT_UART_MS = 100

# , tx=Pin(4), rx=Pin(5),
uart0 = UART(0, baudrate=115200, timeout=WAIT_UART_MS)
led = Pin('LED', Pin.OUT, value=0)
buf = b''


def led_on():
    led.on()
    return b'on'


def led_off():
    led.off()
    return b'off'


COMMANDS = {
    b'led_on': led_on,
    b'led_off': led_off,
}


def run_cmd(cmd):
    if cmd in COMMANDS:
        print(f"Running {cmd:s}")
        uart0.write(COMMANDS[cmd]() + b'\r\n')
    else:
        print(f"Invalid Command: {cmd:s}")


while (True):
    char = uart0.read()
    if not char:
        continue
    
    buf += char
    
    while True:
        idx = buf.find(b'\r')
        if idx < 0:
            break
        token = buf[:idx].strip()
        buf = buf[idx+1:]
        run_cmd(token)
        break