import board, digitalio, time, pwmio

# ====================== PIN SETUP ======================
def init_io(pin, direction, pull=None):
    io = digitalio.DigitalInOut(pin)
    io.direction = direction
    if pull is not None: io.pull = pull
    return io

# Buttons: Arm (GP18-3v3), Reset (GP19-GND), Tilt Proxy (GP20-GND)
btn_arm   = init_io(board.GP18, digitalio.Direction.INPUT, digitalio.Pull.DOWN)
btn_reset = init_io(board.GP19, digitalio.Direction.INPUT, digitalio.Pull.UP)
btn_tilt  = init_io(board.GP20, digitalio.Direction.INPUT, digitalio.Pull.UP)

# LEDs
led_g = init_io(board.GP2, digitalio.Direction.OUTPUT)
led_r = init_io(board.GP3, digitalio.Direction.OUTPUT)
led_y = init_io(board.GP4, digitalio.Direction.OUTPUT)

# Buzzer (GP6) & Servo (GP15)
bz_pwm = pwmio.PWMOut(board.GP6, frequency=1000, duty_cycle=0, variable_frequency=True)
sv_pwm = pwmio.PWMOut(board.GP15, frequency=50)

# Ultrasonic
trig = init_io(board.GP16, digitalio.Direction.OUTPUT)
echo = init_io(board.GP17, digitalio.Direction.INPUT)

# ====================== FUNCTIONS ======================
def get_dist():
    trig.value = True
    time.sleep(0.00001)
    trig.value = False
    t1 = time.monotonic()
    while not echo.value:
        if time.monotonic() - t1 > 0.02: return 999
    t2 = time.monotonic()
    while echo.value:
        if time.monotonic() - t2 > 0.02: return 999
    return (time.monotonic() - t2) * 17150

def set_servo_angle(angle):
    # Duty cycle calculation for Wokwi SG90 Servo
    # 0 deg = ~1638, 180 deg = ~8192
    duty = int(((angle / 180) * 6554) + 1638)
    sv_pwm.duty_cycle = duty

# ====================== INITIAL STATE ======================
system_armed = False
alarm_active = False
print("--- INITIALIZING SERVO (CLOSE WINDOW) ---")
set_servo_angle(0)
time.sleep(1)
print("--- SYSTEM READY ---")

# ====================== MAIN LOGIC ======================
while True:
    # --- PART 3: TILT OVERRIDE ---
    if not btn_tilt.value:
        print("[DEBUG] TILT DETECTED")
        led_y.value = True
        print("[DEBUG] ACTION: OPENING WINDOW")
        set_servo_angle(180)
        
        # Emergency Siren
        for i in range(4):
            bz_pwm.frequency, bz_pwm.duty_cycle = 3500, 32768
            time.sleep(0.15)
            bz_pwm.frequency, bz_pwm.duty_cycle = 2500, 32768
            time.sleep(0.15)
            
        bz_pwm.duty_cycle = 0
        led_y.value = False
        while not btn_tilt.value: pass 
        continue

    # --- PART 1: ARMING ---
    if not system_armed and btn_arm.value:
        print("[DEBUG] ARMING SYSTEM")
        system_armed = True
        led_g.value = True
        bz_pwm.frequency, bz_pwm.duty_cycle = 1200, 32768
        time.sleep(0.2)
        bz_pwm.duty_cycle = 0
        while btn_arm.value: pass 

    # --- PART 2: INTRUSION ---
    if system_armed:
        dist = get_dist()
        if dist < 50:
            if not alarm_active:
                print(f"[DEBUG] INTRUDER AT {dist:.1f} cm")
                alarm_active = True

        if alarm_active:
            led_r.value = True
            bz_pwm.frequency, bz_pwm.duty_cycle = 800, 32768
            
            if not btn_reset.value:
                print("[DEBUG] RESET PRESSED")
                alarm_active = system_armed = False
                led_r.value = led_g.value = bz_pwm.duty_cycle = 0
                print("[DEBUG] ACTION: CLOSING WINDOW")
                set_servo_angle(0)
                time.sleep(0.5)

    time.sleep(0.05)