from machine import Pin
import time
from utime import sleep

#to handle pin interrupt
def PinId(pin, buttons, button_start_id):
    # find the index of the pin in the buttons list and calculate the pin ID based on BUTTON_START_ID
    button_idx = buttons.index(pin)
    return button_start_id + button_idx

def interrupt_callback(pin, buttons, button_start_id):
    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 to get the numeric pin
        print(f'key press: {PinId(pin, buttons, button_start_id) - BUTTON_START_ID}')

def main():
    sleep(0.01)
    print('Program starting')

    BUTTON_COUNT = 3
    LED_COUNT = 9
    INPUT_COUNT = 4

    global BUTTON_START_ID  # to make BUTTON_START_ID to interrupt_callback
    BUTTON_START_ID = 16
    LED_GPIO_START = 7
    global key_presses, last_button_time_stamp
    last_button_time_stamp = 0
    key_presses = []
    output_value = 0
    PASSCODE_LENGTH = 0

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

    # Pushbuttons Pins define
    global buttons  # Make buttons to interrupt_callback
    buttons = []
    for btn_idx in range(0, BUTTON_COUNT):
        buttons.append(Pin(BUTTON_START_ID + btn_idx, Pin.IN, Pin.PULL_DOWN))
        # Pass buttons and BUTTON_START_ID to the interrupt callback
        buttons[-1].irq(trigger=Pin.IRQ_FALLING, 
                       handler=lambda pin: interrupt_callback(pin, buttons, BUTTON_START_ID))

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

    # Definining the GPIO pins for MUX
    MUX1_OUTPUT_PIN = 26
    MUX1_S0_PIN = 27
    MUX1_S1_PIN = 28
    mux_in = Pin(MUX1_OUTPUT_PIN, Pin.IN, Pin.PULL_DOWN)
    s0 = Pin(MUX1_S0_PIN, Pin.OUT)
    s1 = Pin(MUX1_S1_PIN, Pin.OUT)

    last_dev = -1
    while True:
        # the slide switch and logic gates and muxes
        binary_code = 0
        for selector_val in range(INPUT_COUNT):
            s1_val = (selector_val >> 1) & 1
            s0_val = selector_val & 1
            s1.value(s1_val)
            s0.value(s0_val)
            sleep(0.02)
            binary_code += (pow(2, selector_val) * mux_in.value())

        binary_str = "0" * (INPUT_COUNT - len(bin(binary_code)[2:])) + bin(binary_code)[2:]

        #this is for the password and input from push buttons
        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()