from machine import Pin, PWM
from utime import sleep_ms

# ========== PIN SETUP ==========
btns = [
    Pin(5, Pin.IN, Pin.PULL_UP),
    Pin(4, Pin.IN, Pin.PULL_UP),
    Pin(3, Pin.IN, Pin.PULL_UP),
    Pin(2, Pin.IN, Pin.PULL_UP)
]

green_led = Pin(15, Pin.OUT)
red_led = Pin(0, Pin.OUT)

buzzer = PWM(Pin(1))
buzzer.duty_u16(0)

# ========== SYSTEM VARIABLES ==========
Correct_Password = [0, 1, 2, 3]
Entered_Password = []
Failed_Attempts = 0
Max_Attempts = 3

def tone(freq, duration):
    buzzer.freq(freq)
    buzzer.duty_u16(32768)
    sleep_ms(duration)
    buzzer.duty_u16(0)

print("--- System Ready! Please enter 4-digit code ---")

while True:
    for i in range(4):
        if btns[i].value() == 0:
            tone(400, 100)
            Entered_Password.append(i)
            print(f"Entered: {Entered_Password}")
        sleep_ms(20)

    if len(Entered_Password) == 4:
        #print("\nEvaluating Code: ****")
        pass
        
        if Entered_Password == Correct_Password:
            print(">> Access Granted! Welcome. <<\n")
            green_led.value(1)
            tone(1000, 400)
            sleep_ms(1000)
            green_led.value(0)
            Failed_Attempts = 0
        else:
            Failed_Attempts += 1
            print(f">> Wrong Code! Attempts left: {Max_Attempts - Failed_Attempts} <<\n")
            red_led.value(1)
            tone(200, 500)
            sleep_ms(500)
            red_led.value(0)
        
        Entered_Password = []

    if Failed_Attempts >= Max_Attempts:
        print("!!! SECURITY LOCKOUT: Too many failed attempts !!!\n")
        red_led.value(1)
        for _ in range(5):
            tone(2500, 150)
            sleep_ms(100)
        
        red_led.value(0)

        Failed_Attempts = 0
        Entered_Password = []

        print("--- System Reset. Try again ---")
        
    sleep_ms(20)