from machine import Pin, Timer
from utime import sleep, ticks_ms
import utils # local library


# Define global variables/constants
LEDS_START_ID = 7
LEDS_COUNT = 9
leds = utils.init_out_pins(LEDS_START_ID, LEDS_COUNT)

BUTTONS_START_ID = 16 
BUTTONS_COUNT = 3
buttons = utils.init_in_pins(BUTTONS_START_ID, BUTTONS_COUNT)

SELECTORS_START_ID = 27
SELECTORS_COUNT = 2
selectors = utils.init_out_pins(SELECTORS_START_ID, SELECTORS_COUNT)

PASSWORD = "021"
selected_led_id = None # Updated in the main function




input_password = ""
last_press = 0

def interrupt_callback(pin):
    global last_press
    global input_password

    current_press = ticks_ms()

    if (current_press - last_press) > 200: # Debounce guard of 200ms
        button_index = buttons.index(pin)
        input_password += str(button_index)

        print(f"Pressed Button: {button_index}")
        last_press = current_press
 

        # Check if input is long enough
        if len(input_password) >= len(PASSWORD):
            if input_password == PASSWORD:
                print("Correct password.")
                if selected_led_id < len(leds):
                    print(f"--- Toggled LED: {selected_led_id} ---")
                    leds[selected_led_id].toggle()
                else:
                    print("---Failed to toggle LED---")
                    print(f"--> Error: out of range LED *{selected_led_id}*")
                    print(f"--> valid range is [0-{len(leds)- 1}], please try again.")
            else:
                print("Incorrect password, please try again.")

            input_password = "" # Reset after length of password is exceeded


def clear_input(timer): 
    global input_password

    if ticks_ms() - last_press > 5000 and input_password:
        input_password = "" # Clear
        print("-- Your input has been cleared due to inactivity --")


def main():
    # Add interrupt handlers to buttons
    utils.init_irq_pins(pins=buttons, callback=interrupt_callback)

    # Every 2s, i.e.
    # Max delay of 2s
    input_timer = Timer()
    input_timer.init(mode=Timer.PERIODIC, period=2000, callback=clear_input)

    # Initialize the mux input pin
    mux_in = Pin(26, Pin.IN, Pin.PULL_DOWN)

    upper_bound = 2**len(selectors)

    global selected_led_id
    while True:
        output = 0
        # Iterate over the mux inputs
        for i in range(upper_bound):
            binary = utils.decimal_to_binary(i, length=len(selectors)) 
            for selector_index in range(len(selectors)):
                # Set selector output
                selectors[selector_index].value(int(binary[selector_index])) 
            output += mux_in.value() * (2**i)

        if output != selected_led_id:
            print(f"Selected LED: {output}")
            selected_led_id = output

        sleep(0.2) # short delay



if __name__ == "__main__": 
    main()