from machine import Pin
from time import sleep_ms

# GPIO pins for segments A-G (change these to your wiring)
SEG_PINS = [0, 1, 2, 3, 4, 5, 6, ]

# GPIO pins for digit select (two digits)
DIGIT_PINS = [8, 9]

# Button pin (active low)
BUTTON_PIN = 15

# Setup pins
segments = [Pin(pin, Pin.OUT) for pin in SEG_PINS]
digits = [Pin(pin, Pin.OUT) for pin in DIGIT_PINS]
button = Pin(BUTTON_PIN, Pin.IN, Pin.PULL_UP)

# 7-segment digit patterns for 0-9 (common cathode)
digit_patterns = [
    0b00111111,  # 0
    0b00000110,  # 1
    0b01011011,  # 2
    0b01001111,  # 3
    0b01100110,  # 4
    0b01101101,  # 5
    0b01111101,  # 
    0b01111111,  # 8
    0b01101111   # 9
]

# Operation list and index
operations = ['ADD', 'SUB', 'MUL', 'DIV']
current_op = 0

# Fixed input numbers
num1 = 4
num2 = 2

def display_digit(digit_index, value):
    # Turn off both digits
    for d in digits:
        d.value(0)
    
    # Set segments for the digit
    pattern = digit_patterns[value]
    for i in range(7):  # Only A-G segments, ignore DP here
        segments[i].value((pattern >> i) & 1)
    segments[7].value(0)  # DP off
    
    # Turn on the selected digit
    digits[digit_index].value(1)

def get_result():
    global num1, num2, current_op
    if operations[current_op] == 'ADD':
        return num1 + num2
    elif operations[current_op] == 'SUB':
        return num1 - num2
    elif operations[current_op] == 'MUL':
        return num1 * num2
    elif operations[current_op] == 'DIV':
        return num1 // num2 if num2 != 0 else 0

def button_pressed():
    # Simple debounce
    if button.value() == 0:
        sleep_ms(20)
        if button.value() == 0:
            while button.value() == 0:
                pass  # wait for release
            return True
    return False

def main_loop():
    global current_op
    
    while True:
        if button_pressed():
            current_op = (current_op + 1) % len(operations)
        
        result = get_result()
        
        # Clamp result to 0-99 for display
        if result < 0:
            result = 0
        elif result > 99:
            result = 99
        
        # Display result by multiplexing digits
        tens = result // 10
        ones = result % 10
        
        di