from keypad import Keypad
from machine import Pin, PWM
from time import sleep

# Define the secret code and initial state
secretCode = '23689351'
isLocked = True  # Start in the LOCKED state
inbuffer = "--------"

print("State = LOCKED")  # Initial state

# Servo setup on GPIO 27
servo_pin = Pin(27)  # GPIO 27 for servo control
pwm = PWM(servo_pin)
pwm.freq(50)  # Standard servo frequency: 50 Hz

# LED setup
locked_led = Pin(5, Pin.OUT)  # GPIO 5 for LOCKED state LED
unlocked_led = Pin(6, Pin.OUT)  # GPIO 6 for UNLOCKED state LED

# LCD setup (Manual control)
lcd_rs = Pin(12, Pin.OUT)
lcd_enable = Pin(11, Pin.OUT)
lcd_d4 = Pin(10, Pin.OUT)
lcd_d5 = Pin(9, Pin.OUT)
lcd_d6 = Pin(8, Pin.OUT)
lcd_d7 = Pin(7, Pin.OUT)

# Helper function to send a nibble to the LCD
def lcd_send_nibble(nibble):
    lcd_d4.value((nibble >> 0) & 1)
    lcd_d5.value((nibble >> 1) & 1)
    lcd_d6.value((nibble >> 2) & 1)
    lcd_d7.value((nibble >> 3) & 1)
    lcd_enable.on()
    sleep(0.001)
    lcd_enable.off()

# Helper function to send a byte to the LCD
def lcd_send_byte(byte, is_data):
    lcd_rs.value(is_data)
    lcd_send_nibble(byte >> 4)  # High nibble
    lcd_send_nibble(byte & 0x0F)  # Low nibble
    sleep(0.002)

# set up the LCD
def lcd_init():
    sleep(0.02)  
    lcd_send_nibble(0x03)
    sleep(0.005)
    lcd_send_nibble(0x03)
    sleep(0.005)
    lcd_send_nibble(0x03)
    lcd_send_nibble(0x02)  # Set to 4-bit mode

    lcd_send_byte(0x28, False)  
    lcd_send_byte(0x0C, False)  
    lcd_send_byte(0x01, False)  # clears the  display
    sleep(0.002)
    lcd_send_byte(0x06, False)  

# Write a string to the LCD
def lcd_write(text, line):
    line_addresses = [0x00, 0x40] 
    lcd_send_byte(0x80 | line_addresses[line], False)  # Set cursor position
    for char in text:
        lcd_send_byte(ord(char), True)

# locked seevo angle 
def set_servo_angle(angle):
    # Change servo angle to show its unlcoked 
    duty_u16 = int((1600 + (angle / 180) * 6450))
    pwm.duty_u16(duty_u16)

# shows LEDs are based of the displaying of the locked/unlcoked messgae 
def update_status():
    if isLocked:
        locked_led.on()  # Turn on LOCKED LED
        unlocked_led.off()  # Turn off UNLOCKED LED
        lcd_write("State: LOCKED", 0)
    else:
        locked_led.off()  # Turn off LOCKED LED
        unlocked_led.on()  # Turn on UNLOCKED LED
        lcd_write("State: UNLOCKED", 0)

# Start with servo at 0 degrees (locked state) and update status
lcd_init()
set_servo_angle(0)
update_status()

# Callback function to handle key presses
def keyPressed(keyValue):
    global isLocked, inbuffer
    if isLocked:
        if keyValue == '#':  # User confirms code entry
            if inbuffer == secretCode:  # If the entered code matches
                isLocked = False
                set_servo_angle(90)  # Unlock: Move servo to 90 degrees
                print(" - Correct, State = UNLOCKED")
                update_status()  # Update status (LEDs and LCD)
            else:
                print(" - Incorrect code.")
            inbuffer = "--------"  # Reset the buffer after each attempt
        else:  # Add the new digit to the buffer
            inbuffer = inbuffer[1:] + keyValue
            print(keyValue, end="")
    elif keyValue == '*':  # Lock the padlock
        isLocked = True
        set_servo_angle(0)  # Lock: Move servo to 0 degrees
        print("State = LOCKED")
        update_status()  # Update status (LEDs and LCD)

# Setup the keypad object with the correct pins and callback
kp = Keypad(rows=(Pin(26), Pin(22), Pin(21), Pin(20)),
            columns=(Pin(19), Pin(18), Pin(17), Pin(16)),
            callback=keyPressed)