from machine import Pin, I2C, PWM
import time

# Initialize pins
button0 = Pin(2, Pin.IN, Pin.PULL_DOWN)
button1 = Pin(3, Pin.IN, Pin.PULL_DOWN)
button2 = Pin(4, Pin.IN, Pin.PULL_DOWN)
green_led = Pin(15, Pin.OUT)
red_led = Pin(16, Pin.OUT)
buzzer = Pin(4, Pin.OUT)

# Initialize I2C for LCD
i2c = I2C(0, sda=Pin(0), scl=Pin(1), freq=400000)

# Initialize servo
servo = PWM(Pin(12))
servo.freq(50)

# Access control data
ACCESS_CODES = {
    0b001: "Student",
    0b010: "Lecturer", 
    0b011: "Technician"
}

def read_buttons():
    """Read the 3-bit binary code from buttons"""
    b0 = button0.value()
    b1 = button1.value()
    b2 = button2.value()
    return (b2 << 2) | (b1 << 1) | b0

def unlock_servo():
    """Simulate unlocking by rotating servo to 90 degrees"""
    servo.duty_u16(4915)  # ~90 degrees
    time.sleep(2)

def lock_servo():
    """Simulate locking by rotating servo to 0 degrees"""
    servo.duty_u16(1966)  # ~0 degrees
    time.sleep(0.5)

def access_granted(user_type):
    """Handle granted access sequence"""
    print(f"ACCESS GRANTED - {user_type}")
    
    # Visual feedback
    green_led.on()
    red_led.off()
    
    # LCD display
    lcd.clear()
    lcd.move_to(0, 0)
    lcd.putstr("ACCESS GRANTED")
    lcd.move_to(0, 1)
    lcd.putstr(f"Welcome {user_type}!")
    
    # Sound feedback (2 short beeps)
    for _ in range(2):
        buzzer.on()
        time.sleep(0.1)
        buzzer.off()
        time.sleep(0.1)
    
    # Unlock servo
    unlock_servo()
    green_led.off()
    lock_servo()

def access_denied():
    """Handle denied access sequence"""
    print("ACCESS DENIED")
    
    # Visual feedback
    red_led.on()
    green_led.off()
    
    # LCD display
    lcd.clear()
    lcd.move_to(0, 0)
    lcd.putstr("ACCESS DENIED")
    lcd.move_to(0, 1)
    lcd.putstr("Invalid Card")
    
    # Sound feedback (continuous beep)
    buzzer.on()
    time.sleep(1.5)
    buzzer.off()
    red_led.off()

def main():
    """Main program loop"""

    lcd.putstr("Enter Binary")
    lcd.move_to(0, 1)
    lcd.putstr("Code: ---")
    
    previous_code = -1
    
    while True:
        # Read current code
        code = read_buttons()
        
        # Only process if code changed
        if code != previous_code:
            previous_code = code
            
            # Update LCD display
            lcd.move_to(6, 1)
            lcd.putstr(f"{code:03b}")
            
            # Check access
            if code in ACCESS_CODES:
                access_granted(ACCESS_CODES[code])
            elif code == 0b111:
                access_denied()
            else:
                # Handle other invalid codes
                lcd.clear()
                lcd.putstr("Invalid Code")
                lcd.move_to(0, 1)
                lcd.putstr(f"{code:03b} Unknown")
                time.sleep(1)
                lcd.clear()
                lcd.putstr("Enter Binary")
                lcd.move_to(0, 1)
                lcd.putstr("Code: ---")
        
        time.sleep(0.05)