import machine
import time
from utime import sleep
# count of objects
BUTTON_COUNT = 2
LED_COUNT = 4
INPUT_COUNT = 2
# Constants for pin numbers
BUTTON_START_ID = 16
LED_GPIO_START = 7
last_button_time_stamp = 0
key_presses = []

# Define the selector pins
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)
prev_binary_code = 0


def PinId(pin):
    # Pin(GPIO17, mode=IN, pull=PULL_DOWN)
    # the pin value is in the format above
    # and the pin id, i.e. 7 or 17, can be single or double digit
    # So, we filter the characters 8-10, 
    # which would be '7,' or '17' depending on the pin,
    # then, we remove any ',' character at the end
    # and we are left with the numeric value of the pin, i.e. 7 or 17
    return int(str(pin)[8:11].rstrip(","))



def interrupt_callback(pin):
    global last_button_time_stamp

    cur_button_ts = time.ticks_ms()
    button_press_delta = cur_button_ts - last_button_time_stamp
    if button_press_delta > 200:
        last_button_time_stamp = cur_button_ts
        key_presses.append(pin)
        # Call the PinId method to get the numeric pin value
        print(f'key press: {PinId(pin) - BUTTON_START_ID}')

def main():
    global key_presses
    global last_button_time_stamp
    PASSCODE_LENGTH = 0


    buttons = []
    for btn_idx in range(0, BUTTON_COUNT):
        buttons.append(machine.Pin(BUTTON_START_ID + btn_idx, machine.Pin.IN, machine.Pin.PULL_DOWN))
        buttons[-1].irq(trigger=machine.Pin.IRQ_FALLING, handler=interrupt_callback)

    PASS_CODE = [buttons[1], buttons[0],buttons[2]]
    PASSCODE_LENGTH = len(PASS_CODE)

    out_pins = []
    for out_id in range(0, LED_COUNT):
        out_pins.append(machine.Pin(LED_GPIO_START + out_id, machine.Pin.OUT))

    last_dev = -1


while True:
    binary_code = 0
    for selector_val in range(4):
        s0.value(selector_val % 2)
        s1.value(selector_val // 2)
        sleep(0.020)
        binary_code += (pow(2, selector_val) * mux_in.value())
    if binary_code != prev_binary_code:
        print(f"Decimal representation: {binary_code}")
        prev_binary_code = binary_code
    sleep(0.100)
        

    if len(key_presses) >= PASSCODE_LENGTH:
        if key_presses[:PASSCODE_LENGTH] == PASS_CODE:
            print('correct passcode')
            if binary_code < LED_COUNT:
                print(f'toggling: {binary_code}')
                out_pins[binary_code].toggle()
            else:
                print(f'invalid output: {binary_code}, ' + \
                f'valid range: 0-{len(out_pins) - 1}, doing nothing')
        else:
            print('wrong passcode')
        print('')
        key_presses = key_presses[PASSCODE_LENGTH:]

if __name__ == "__main__":
    main()