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

secretCode = '24856059'
isLocked = False
inbuffer = "--------"

failedAttempts = 0          # Starting point
maxAttempts = 3             # Max attempts before lockout
lockoutTime = 10            # Lockout for seconds

pwm = PWM(Pin(10),freq = 50)               # PWM output to control servo position

led1 = Pin(0, Pin.OUT)                     # Set Up LEDs, led1 (blue) indicates a key is pressed
led2 = Pin(1, Pin.OUT)                     # led2 (red) indicates state = locked
led3 = Pin(2, Pin.OUT)                     # led3 (green) indicates state = unlocked
led4 = Pin(28, Pin.OUT)                    # led4 (amber) indicates lockdown

def keyPressed(keyValue):
   global isLocked, inbuffer, failedAttempts          # Global variables are stored between function calls

   led1.on()                                                        # led1 Turns on for 0.1 seconds when a key is pressed
   time.sleep(0.1)
   led1.off()

   if isLocked:
      if keyValue == '#':              # User is trying to unlock
         if inbuffer == secretCode:    # Success only if the code matches
            isLocked = False
            failedAttempts = 0
            pwm.duty_u16(1600)         # Sets the Servo to Vertical for unlocked
            led3.on()                  # LEDs Change accordingly if succesfully unlocked
            led2.off()
            led4.off()
            print(" - Correct, State = UNLOCKED") 
         else:
            print(" - Incorrect code.") # if code is wrong, message is printed, Failed attempts is +1 (ref. python functions), and LED change accordingly
            failedAttempts += 1
            led2.on()
            led3.off()
            led4.off()

            if failedAttempts >= maxAttempts:   #if failedAttempts >= 3, lockout occurs and message is printed when a key is pressed
               print("TOO MANY FAILED ATTEMPTS - LOCKED OUT for", lockoutTime, "seconds")
               failedAttempts = 0 # reset for next round
               led4.on()
               time.sleep(lockoutTime)   # Freeze system



         inbuffer = "--------"                  # Wrong code so reset the buffer
      else:                                     # New number needs storing in the buffer:
         inbuffer = inbuffer[1:] + keyValue     # Move buffer to the left and add new value
         print(keyValue, end="")

   elif keyValue == '*':                        # Unlocked and '*' pressed so change the 
      isLocked = True                           # state to locked.
      pwm.duty_u16(4825) # Sets the Servo to Horizontal for Unlocked (ref. servo datasheet)
      led2.on()
      led3.off()
      led4.off()
      print("State = LOCKED")

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