import time
import board
import digitalio

# -------------------------
# Keypad setup (4x4 Matrix)
# -------------------------
rows = [board.GP13, board.GP12, board.GP11, board.GP10]
cols = [board.GP9, board.GP8, board.GP7, board.GP6]

row_pins = []
col_pins = []

for r in rows:
    pin = digitalio.DigitalInOut(r)
    pin.direction = digitalio.Direction.OUTPUT
    pin.value = True
    row_pins.append(pin)

for c in cols:
    pin = digitalio.DigitalInOut(c)
    pin.direction = digitalio.Direction.INPUT
    pin.pull = digitalio.Pull.UP
    col_pins.append(pin)

keys = [
    ['1','2','3','A'],
    ['4','5','6','B'],
    ['7','8','9','C'],
    ['*','0','#','D']
]

def scan_keypad():
    for row_num, row_pin in enumerate(row_pins):
        row_pin.value = False  
        for col_num, col_pin in enumerate(col_pins):
            if not col_pin.value:  
                row_pin.value = True 
                return keys[row_num][col_num]
        row_pin.value = True 
    return None

# -------------------------
# 7-Segment & BCD Setup
# -------------------------
# Pins matching your logic: A=GP2, B=GP3, C=GP4, D=GP5
A = digitalio.DigitalInOut(board.GP2) 
B = digitalio.DigitalInOut(board.GP3) 
C = digitalio.DigitalInOut(board.GP4) 
D = digitalio.DigitalInOut(board.GP5) 

for pin in [A, B, C, D]:
    pin.direction = digitalio.Direction.OUTPUT

bcd_pins = [A, B, C, D]

s72 = digitalio.DigitalInOut(board.GP0) # TENS
s71 = digitalio.DigitalInOut(board.GP1) # ONES
s72.direction = 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      # Active Low
    time.sleep(0.001)
    pin.value = 1

def turn_off():
    send_bcd(15) # 15 (1111) usually blanks the CD4511
    latch(s72)
    latch(s71)

def display_number(num):
    tens = num // 10
    ones = num % 10
    send_bcd(tens)
    latch(s72)
    send_bcd(ones)
    latch(s71)

# -------------------------
# User Input Logic
# -------------------------
def get_user_input():
    value = ""
    print("\n--- Enter Countdown Value (0-99) ---")
    print("Press # to confirm")
    turn_off() # Clear display for new input

    while True:
        key = scan_keypad()
        if key:
            if key.isdigit():
                if len(value) < 2:
                    value += key
                    print("Input:", value)
                    display_number(int(value)) # Show number as you type
            elif key == '#':
                if value == "":
                    print("Error: Enter digits first!")
                else:
                    return int(value)
            time.sleep(0.3) # Debounce
        time.sleep(0.01)

# -------------------------
# Main Program Loop
# -------------------------
print("System Initialized (No Switch/No LEDs)")

while True:
    # 1. Get the time from user via keypad
    x = get_user_input()
    
    # 2. Run the countdown on 7-segment only
    print(f"Starting Countdown: {x}")
    for i in range(x, -1, -1):
        display_number(i)
        print("Time remaining:", i)
        time.sleep(1)
    
    print("Countdown Finished!")
    time.sleep(1) # Short pause before asking again