from machine import Pin
import time

# Pin Definitions for 74HC595
SD = Pin(0, Pin.OUT)      # Serial Data Input
ST_CP = Pin(1, Pin.OUT)   # Storage Register Clock (Latch)
SH_CP = Pin(2, Pin.OUT)   # Shift Register Clock

# Push buttons
push_button_HIGH = Pin(21, Pin.IN, Pin.PULL_DOWN)
push_button_LOW = Pin(20, Pin.IN, Pin.PULL_DOWN)

# Global Variables
magic_key = 0xF0  # Target pattern: 11110000
bits_entered = 0  # Shift register for storing bits

def shift_bit(bit):
    global bits_entered

    # Send bit to SD
    SD.value(bit)
    
    # Pulse SH_CP (Shift clock)
    SH_CP.value(1)
    time.sleep_us(10)
    SH_CP.value(0)

    # Pulse ST_CP (Store clock)
    ST_CP.value(1)
    time.sleep_us(10)
    ST_CP.value(0)

    # Shift bits_entered and append new bit
    bits_entered = ((bits_entered << 1) | bit) & 0xFF

    print(f"Current bits: {bits_entered:08b}")

    if bits_entered == magic_key:
        print("SUCCESS!")
        Pin(5, Pin.OUT).value(1)   # Green LED ON
        Pin(6, Pin.OUT).value(0)   # Red LED OFF
    elif bits_entered & 0xF0 == 0xF0 or bits_entered & 0x0F == 0x00:
        print("FAIL!")
        Pin(5, Pin.OUT).value(0)   # Green LED OFF
        Pin(6, Pin.OUT).value(1)   # Red LED ON

def push_button_HIGH_interrupt_handler(pin):
    print("Push button HIGH interrupt detected...")
    shift_bit(1)

def push_button_LOW_interrupt_handler(pin):
    print("Push button LOW interrupt detected...")
    shift_bit(0)

# Setup interrupt handlers
push_button_HIGH.irq(trigger=Pin.IRQ_RISING, handler=push_button_HIGH_interrupt_handler)
push_button_LOW.irq(trigger=Pin.IRQ_RISING, handler=push_button_LOW_interrupt_handler)