from machine import Pin
from time import sleep

green = Pin(25, Pin.OUT)
red = Pin(26, Pin.OUT)
yellow = Pin(27, Pin.OUT)
blue = Pin(14, Pin.OUT)

entry_button = Pin(18, Pin.IN, Pin.PULL_UP)
exit_button = Pin(19, Pin.IN, Pin.PULL_UP)

car_count = 0


def update_status():
    if car_count >= 15:
        green.off()
        red.on()
    else:
        green.on()
        red.off()


green.on()
red.off()
yellow.off()
blue.off()

while True:

    if entry_button.value() == 0:
        if car_count < 15:
            car_count += 1

            yellow.on()
            update_status()
            sleep(1)
            yellow.off()

        while entry_button.value() == 0:
            sleep(0.05)

    if exit_button.value() == 0:
        if car_count > 0:
            car_count -= 1

            blue.on()
            update_status()
            sleep(1)
            blue.off()

        while exit_button.value() == 0:
            sleep(0.05)

    sleep(0.05)