import board
import time
import digitalio

y = 30
count = y
interval = 1.0

# Setup Button
sw1 = digitalio.DigitalInOut(board.GP15)
sw1.direction = digitalio.Direction.INPUT
sw1.pull = digitalio.Pull.UP

sw2 = digitalio.DigitalInOut(board.GP16)
sw2.direction = digitalio.Direction.INPUT
sw2.pull = digitalio.Pull.UP

# Setup BCD Pins (A, B, C, D)
pins = [board.GP2, board.GP3, board.GP4, board.GP5]
bcd_pins = []
for p in pins:
    led = digitalio.DigitalInOut(p)
    led.direction = digitalio.Direction.OUTPUT
    bcd_pins.append(led)

# Setup Latch Pins
s72 = digitalio.DigitalInOut(board.GP0) # Tens
s72.direction = digitalio.Direction.OUTPUT

s71 = digitalio.DigitalInOut(board.GP1) # Ones
s71.direction = digitalio.Direction.OUTPUT

def send_bcd(value):
    for i in range(4):
    
        bcd_pins[i].value = (value >> i) & 1

def latch(pin):
    pin.value = 0
    time.sleep(0.001)
    pin.value = 1

def display_number(num):
    tens = num // 10
    ones = num % 10

    # Tens
    send_bcd(tens)
    latch(s72)
    
    # Ones
    send_bcd(ones)
    latch(s71)

def display_off():
    send_bcd(0)
    latch(s72)
    latch(s71)

count = 25
running = False

display_off()

count = 30 
running = False
display_off()

while True:
    display_number(count)

    # Start Button (SW1)
    if not sw1.value:
        if count > 0: 
            running = True
            print("Start Countdown")
        time.sleep(0.3)

    # Reset Button (SW2)
    if not sw2.value:
        display_off()
        running = False
        count = 30 
        display_number(count)
        print("Reset to 30")
        time.sleep(10)  

    
    if running:
        time.sleep(interval)
        if count > 0:
            count -= 1
            print("Time: {:02d}".format(count))
        
        
        if count == 0:
            running = False
            display_number(0) 
            print("Time Up!")