system-status/system-status.py

import sys
import signal

from gpiozero import Button
from signal import pause
from subprocess import check_call
from time import sleep
from unicornhatmini import UnicornHATMini

POWER_BUTTON_GPIO_PIN = 5
HOLD_TIME_IN_SECONDS = 1


class SystemStatus:
    def __init__(self, hat):
        self.hat = hat
        self.hat.set_brightness(0.1)

    def display(self):
        self.hat.set_pixel(0, 0, 0, 0, 50)
        self.hat.show()

    def exit(self):
        self.hat.set_all(50, 0, 0)
        self.hat.show()
        sleep(0.50)
        self.hat.set_all(0, 0, 0)
        self.hat.show()

    def terminate(self):
        for _ in range(3):
            self.hat.set_all(50, 0, 0)
            self.hat.show()
            sleep(0.25)
            self.hat.set_all(0, 0, 0)
            self.hat.show()
            sleep(0.25)


def cleanExit(systemStatus, button):
    def exit(signum, frame):
        button.close()
        systemStatus.exit()
        sys.exit(0)

    return exit


def poweroff(systemStatus, button):
    def terminate():
        systemStatus.terminate()
        check_call(['sudo', 'poweroff'])

    return terminate


def main():
    systemStatus = SystemStatus(UnicornHATMini())
    powerButton = Button(POWER_BUTTON_GPIO_PIN, hold_time=HOLD_TIME_IN_SECONDS)
    signal.signal(signal.SIGTERM, cleanExit(systemStatus, powerButton))

    powerButton.when_held = poweroff(systemStatus, powerButton)
    systemStatus.display()

    pause()


if __name__ == '__main__':
    main()