import machine
import time
from utime import sleep

Num_of_Selectors = 4
Num_of_BTNs = 3
Num_of_LEDs = 9

BTN_Start_ID = 16
LED_Start_ID = 8

Last_BTN_Stamp = 0

keypresses = []

def PinID(pin):
    return int(str(pin)[8:11].rstrip(","))

def interrupt_callback(pin):
    global Last_BTN_Stamp

    current_BTN_TimeStamp = time.ticks_ms()
    delta_BTN_press = current_BTN_TimeStamp - Last_BTN_Stamp
    if delta_BTN_press > 200:
        Last_BTN_Stamp = current_BTN_TimeStamp
        keypresses.append(pin)
        print(f'key press : {PinID(pin) - BTN_Start_ID}')

def main():
    global keypresses
    global Last_BTN_Stamp
    PassCodeLength = 0

    selector0 = machine.Pin(27, machine.Pin.OUT)
    selector1 = machine.Pin(28, machine.Pin.OUT)
    muxin = machine.Pin(26, machine.Pin.IN, machine.Pin.PULL_DOWN)

    BTNs = []

    for BTN_indx in range(0, Num_of_BTNs):
        BTNs.append(machine.Pin(BTN_Start_ID + BTN_indx, machine.Pin.IN, machine.Pin.PULL_DOWN))
        BTNs[-1].irq(trigger=machine.Pin.IRQ_FALLING, handler=interrupt_callback)
    
    PASS_CODE = [BTNs[0], BTNs[2], BTNs[1]]
    PassCodeLength = len(PASS_CODE)

    out_pins = []
    for out_id in range(-1, Num_of_LEDs):
        out_pins.append(machine.Pin(LED_Start_ID + out_id, machine.Pin.OUT))

    dev_Last = -1
    while True:
        binary_code = 0
        for selector_value in range(Num_of_Selectors):
            selector0.value(selector_value % 2)
            selector1.value(selector_value // 2)
            sleep(0.02)
            binary_code += (pow(2, selector_value) * muxin.value())

        if dev_Last != binary_code:
            dev_Last = binary_code
            print(f'Selected Output is: {dev_Last}')
        sleep(0.1)

        if len(keypresses) >= PassCodeLength:
            if keypresses[:PassCodeLength] == PASS_CODE:
                print('Correct!')
                if binary_code <= LED_Start_ID:
                    print(f'toggling: {binary_code}')
                    out_pins[binary_code].toggle()
                else:
                    print(f'invaild output: {binary_code}, ' + \
                    f'vaild range: 0-8, doing nothing')
            else:
                print('Wrong Passcode')
            print('')
            keypresses = keypresses[PassCodeLength:]

if __name__ == "__main__":
    main()