import io
import json

from machine import Pin, soft_reset
import time


led_red = Pin(18, Pin.OUT, value=1)  # set LED pin to high voltage to turn off the LED indicator.
led_green = Pin(19, Pin.OUT, value=1)
led_blue = Pin(20, Pin.OUT, value=1)
btn_pin = Pin(2, Pin.OUT, value=1)  # button pin high level means released button state. Low level means pressed state.

config = {
    'device_name': 'fingerbot 1',
    'click_press_time': 0.2,
    'led_blink_time': 0.1,
}
default_config = config.copy()
last_error_msg = None

HELP_INFO = '''Supported commands:
  click_btn - command to switch the Fingerbot actuator position.
  get device_name - read current device name.
  set device_name <new_name> - set new device_name config value.
  set click_press_time <time_in_sec> - modify action button press time (in seconds).
  get last_error_msg - show last reported error message (it is None after reboot).
  get config - show config.json content.
  reset_config - reset config to default values.
  reboot - reboot device.
  machine.soft_reset() - same as reboot. This is an alias that is identical to same REPL command.
  repl - stop program and exit to MicroPython Interactive Interpreter (aka REPL mode).
  help or help() - show this message again. '''


def main_loop():
    print(f'Fingerbot Serial API main_loop started.\n{HELP_INFO}')
    led_red(1)  # turn off the red LED light that could be turned on by 'break' command
    while True:
        try:
            cmd = input().strip()
            if cmd == 'click_btn':
                click_btn()
            elif cmd == 'reboot' or cmd == 'machine.soft_reset()':
                reboot()
            elif cmd == 'reset_config':
                reset_config()
            elif cmd == 'get config':
                report_msg(json.dumps(config))
            elif cmd == 'get last_error_msg':
                report_msg(last_error_msg)
            elif cmd.startswith('get '):
                get_config_param(cmd[4:])
            elif cmd.startswith('set '):
                args = cmd[4:].split(' ', 1)
                set_config_param(args[0], args[1])
            elif cmd == 'repl':
                report_msg('Stop program and exit to MicroPython Interactive Interpreter (aka REPL mode).')
                led_red(0)
                break
            elif cmd == 'help' or cmd == 'help()':
                report_msg(HELP_INFO)
            elif cmd:
                report_error(f'Unsupported command "{cmd}".\n{HELP_INFO}')
        except Exception as e:
            print(str(e))
        except KeyboardInterrupt:
            print('KeyboardInterrupt received. Exit from the Fingerbot Serial API main_loop. ' +
                  'Type "main_loop()" command to start it again from the REPL terminal.')
            break


def click_btn():
    print('Do button click action... ', end='')
    btn_pin(0)
    led_blue(0)
    time.sleep(config.get('click_press_time'))
    btn_pin(1)
    led_blue(1)
    report_msg('Done.')


def get_config_param(param_name: str):
    if param_name in ['device_name', 'click_press_time', 'led_blink_time']:
        report_msg(config.get(param_name))
    else:
        report_error(f'Unknown parameter "{param_name}". ' +
                     f'Known parameters: device_name, click_press_time, led_blink_time.')


def set_config_param(param_name: str, value: str):
    if param_name in ['device_name', 'click_press_time', 'led_blink_time']:
        if param_name in ['click_press_time', 'led_blink_time']:
            config[param_name] = float(value)
        else:
            config[param_name] = value
        save_config_to_file()
        report_msg('Done.')
    else:
        report_error(f'Unknown parameter "{param_name}". ' +
                     f'Known parameters: device_name, click_press_time, led_blink_time.')


def report_msg(msg: str | None):
    print(msg)
    led_green(0)
    time.sleep(config.get('led_blink_time'))
    led_green(1)


def report_error(msg: str):
    print(f'Error: {msg}')
    global last_error_msg
    last_error_msg = msg
    led_red(0)
    time.sleep(config.get('led_blink_time'))
    led_red(1)


def save_config_to_file():
    with io.open('config.json', 'wt') as f:
        json.dump(config, f)


def read_config_from_file_if_exist():
    try:
        with io.open('config.json', 'rt') as f:
            global config
            config = json.load(f)
    except Exception as e:
        report_error(str(e))


def reset_config():
    config.update(default_config)
    save_config_to_file()


def reboot():
    soft_reset()
    report_msg('Reboot device.')


read_config_from_file_if_exist()
main_loop()