import machine
import time
from utime import sleep

# The button pins (GPIO16, GPIO17, GPIO18 with PULL_DOWN)
b0 = machine.Pin(16, machine.Pin.IN, machine.Pin.PULL_DOWN)
b1 = machine.Pin(17, machine.Pin.IN, machine.Pin.PULL_DOWN)
b2 = machine.Pin(18, machine.Pin.IN, machine.Pin.PULL_DOWN)

s0 = machine.Pin(27, machine.Pin.OUT)
s1 = machine.Pin(28, machine.Pin.OUT)

MUX_IN = machine.Pin(26, machine.Pin.IN, machine.Pin.PULL_DOWN)

led_pins = [7, 8, 9, 10, 11, 12, 13, 14, 15]
leds = [machine.Pin(pin, machine.Pin.OUT) for pin in led_pins]

def toggle_led(index):
    leds[index].value(not leds[index].value())

last_press_time = 0
correct_sequence = [b0, b2, b1]
user_sequence = []

last_decimal = -1

def button_callback(pin):

    global last_press_time, correct_sequence, user_sequence, last_decimal

    current_time = time.ticks_ms()

    # Checking if the time difference is greater than 200ms
    if time.ticks_diff(current_time, last_press_time) > 200:

        last_press_time = current_time

        if pin is b0:
            print("B0 is pressed!")
        elif pin is b1:
            print("B1 is pressed!")
        elif pin is b2:
            print("B2 is pressed!")

        user_sequence.append(pin)

        if len(user_sequence) == 3:
            if user_sequence == correct_sequence:
                print("Passcode is correct")
                if 0 <= last_decimal <= 8:
                    print("Toggling : {}".format(last_decimal))
                    toggle_led(last_decimal)
                else:
                    print("Selected output {} out of range. Correct range is [0-8].".format(last_decimal))

            else:
                print("Passcode is wrong.Try again.")
            user_sequence.clear()
        
# Make interrupts to the buttons
b0.irq(trigger=machine.Pin.IRQ_RISING, handler=button_callback)
b1.irq(trigger=machine.Pin.IRQ_RISING, handler=button_callback)
b2.irq(trigger=machine.Pin.IRQ_RISING, handler=button_callback)

while True:
    decimal_value = 0
    
    for channel in range(4):
        s0.value(channel & 1)
        s1.value((channel >> 1) & 1)
        time.sleep(0.01) 
        
        bit = MUX_IN.value()
        
        decimal_value += bit * (2 ** (channel))
    
    if decimal_value != last_decimal:
        last_decimal = decimal_value
        print("Selected output:", decimal_value)

    time.sleep(0.1)