import machine
import time
from utime import sleep

BUTTONS_COUNT = 3  
LEDS_COUNT = 9     
INPUTS_COUNT = 4  
MAX_SELECTION = 16    

BUTTON_BASE = 16
LED_BASE = 7

debounce = 0
key_presses = []

def extract_id(pin):
    return int(''.join(filter(str.isdigit, str(pin))))

def handle_button_interrupt(pin):
    global debounce
    current = time.ticks_ms()
    if current - debounce > 300:
        debounce = current
        pin_id = extract_id(pin)
        if pin_id != -1:  
            key_presses.append(pin_id)
            print(f'You pressed {pin_id - BUTTON_BASE}')
            sleep(0.1)

def leds():
    global led
    led = [machine.Pin(LED_BASE + i, machine.Pin.OUT) for i in range(LEDS_COUNT)]

def main():
    global key_presses, debounce
    PASSCODE_LENGTH = 3

    mux = [
        machine.Pin(27, machine.Pin.OUT),
        machine.Pin(28, machine.Pin.OUT),
        machine.Pin(26, machine.Pin.IN, machine.Pin.PULL_DOWN)
    ]

    buttons = [machine.Pin(BUTTON_BASE + i, machine.Pin.IN, machine.Pin.PULL_DOWN) for i in range(BUTTONS_COUNT)]
    for button in buttons:
        button.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_button_interrupt)

    PASS_CODE = [BUTTON_BASE, BUTTON_BASE + 2, BUTTON_BASE + 1]  
    leds()

    last_dev = -1
    while True:
        binary_code = 0
        
        stable_readings = 0
        stable_value = None
        while stable_readings < 3: 
            current_value = 0
            for i in range(INPUTS_COUNT):
                s0 = (i >> 0) & 1
                s1 = (i >> 1) & 1
                mux[0].value(s0)
                mux[1].value(s1)

                if mux[-1].value() == 1:
                    current_value |= (1 << i)

            if stable_value is None:
                stable_value = current_value
            elif current_value == stable_value:
                stable_readings += 1
            else:
                stable_value = current_value
                stable_readings = 0

        if last_dev != stable_value:
            last_dev = stable_value
            print(f'Selected decimal: {last_dev}')

        if len(key_presses) >= PASSCODE_LENGTH:
            if key_presses[:PASSCODE_LENGTH] == PASS_CODE:
                if last_dev < LEDS_COUNT:
                    led[last_dev].toggle()
                    print(f'Toggle LED: {last_dev}')
                elif last_dev <= MAX_SELECTION:
                    print(f'Out of Range it is {last_dev} (Maximum is 8)')
            else:
                print('Incorrect passcode')
            key_presses = key_presses[PASSCODE_LENGTH:]

if __name__ == "__main__":
    main()