from machine import Pin
from time import sleep

# LEDs for 8 parking slots
led_pins = [Pin(pin, Pin.OUT) for pin in [2, 4, 5, 13, 16, 17, 18, 21]]

# Buttons (external pull-downs required!)
enter_button = Pin(34, Pin.IN)
exit_button = Pin(35, Pin.IN)

# State variables
car_count = 0
MAX_CARS = 8

def update_leds(count):
    for i in range(MAX_CARS):
        led_pins[i].value(1 if i < count else 0)

# Show initial state
update_leds(car_count)
print("System Ready. Cars in lot:", car_count)

# Main loop
while True:
    # Car entering
    if enter_button.value() == 1:
        if car_count < MAX_CARS:
            car_count += 1
            update_leds(car_count)
            print("Car entered. Count:", car_count)
            sleep(0.5)
        else:
            print("Parking full!")
            sleep(0.5)

        # Wait for release
        while enter_button.value():
            sleep(0.01)

    # Car exiting
    if exit_button.value() == 1:
        if car_count > 0:
            car_count -= 1
            update_leds(car_count)
            print("Car exited. Count:", car_count)
            sleep(0.5)
        else:
            print("No cars to exit.")
            sleep(0.5)

        # Wait for release
        while exit_button.value():
            sleep(0.01)

    sleep(0.05)