from machine import Pin, I2C
from time import sleep
from pico_i2c_lcd import I2cLcd

sda = Pin(0)
scl = Pin(1)
i2c = I2C(0, sda=sda, scl=scl, freq=40000)
I2C_ADDR = 39
I2C_ROWS = 2
I2C_COLS = 16
lcd = I2cLcd(i2c, I2C_ADDR, I2C_ROWS, I2C_COLS)

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

keypad_rows = [9, 8, 7, 6]
keypad_columns = [5, 4, 3, 2]

pin = ["7", "8", "6", "0"]
guess = []

gled = Pin(27, Pin.OUT)
rled = Pin(28, Pin.OUT)
relay = Pin(20, Pin.OUT)

col_pins = []
row_pins = []

for x in range(4):
    row_pins.append(Pin(keypad_rows[x], Pin.OUT))
    col_pins.append(Pin(keypad_columns[x], Pin.IN, Pin.PULL_DOWN))

def scankeys():
    cursor_pos = 0
    for row in range(4):
        row_pins[row].value(1)
        for col in range(4):
            if col_pins[col].value() == 1:
                key_press = matrix_keys[row][col]
                print("Key Press:", key_press)
                sleep(0.3)
                guess.append(key_press)
                lcd.move_to(cursor_pos, 1)
                lcd.putstr(''.join(guess))
                cursor_pos += 1
                sleep(0.3)
                
                if len(guess) == len(pin):
                    lcd.clear()
                    checkPin(guess)
                    guess.clear()
        row_pins[row].value(0)

def checkPin(guess):
    if guess == pin:
        print("Inventory is Unlocked")
        gled.value(1)
        relay.value(1)
        lcd.putstr("Unlocked")
    else:
        rled.value(1)
        print("Wrong Pin!!! Inventory remains locked")
        lcd.putstr("Wrong Pin")

def main():
    lcd.putstr("System")
    lcd.move_to(0, 1)
    lcd.putstr("Starting Up...")
    sleep(2)
    lcd.clear()
    lcd.move_to(0, 0)
    lcd.putstr("Enter The Pin")
    while True:
        scankeys()

main()