import board
import digitalio
import analogio
import pwmio
import time

# ================================================================
# PIN SETUP
# ================================================================

# --- Inputs ---
btn_arm = digitalio.DigitalInOut(board.GP0)
btn_arm.switch_to_input(pull=digitalio.Pull.UP)

btn_stop = digitalio.DigitalInOut(board.GP5)
btn_stop.switch_to_input(pull=digitalio.Pull.UP)

pir = digitalio.DigitalInOut(board.GP4)
pir.switch_to_input()

ldr_adc = analogio.AnalogIn(board.GP26)

ldr_dig = digitalio.DigitalInOut(board.GP16)
ldr_dig.switch_to_input()

# --- Outputs ---
buzzer = pwmio.PWMOut(board.GP2, frequency=2000, duty_cycle=0, variable_frequency=True)

led_green = digitalio.DigitalInOut(board.GP3)
led_green.direction = digitalio.Direction.OUTPUT

led_red = digitalio.DigitalInOut(board.GP6)
led_red.direction = digitalio.Direction.OUTPUT

led_yel = digitalio.DigitalInOut(board.GP17)
led_yel.direction = digitalio.Direction.OUTPUT

# --- Stepper Motor Coil Pins ---
coil_Am = digitalio.DigitalInOut(board.GP18)
coil_Am.direction = digitalio.Direction.OUTPUT

coil_Ap = digitalio.DigitalInOut(board.GP19)
coil_Ap.direction = digitalio.Direction.OUTPUT

coil_Bp = digitalio.DigitalInOut(board.GP20)
coil_Bp.direction = digitalio.Direction.OUTPUT

coil_Bm = digitalio.DigitalInOut(board.GP21)
coil_Bm.direction = digitalio.Direction.OUTPUT

# ================================================================
# SETTINGS
# ================================================================

STEPS_PER_REV   = 200
STEP_DELAY      = 0.002       # 2ms in seconds
LUX_THRESHOLD   = 100
PIR_SETTLE      = 0.3         # 300ms in seconds
DEBOUNCE_ARM    = 0.05        # 50ms
DEBOUNCE_STP    = 0.02        # 20ms

# Full-step sequence: [A-, A+, B+, B-]
STEP_SEQUENCE = [
    [True,  False, True,  False],   # Step 1
    [False, True,  True,  False],   # Step 2
    [False, True,  False, True ],   # Step 3
    [True,  False, False, True ],   # Step 4
]

# ================================================================
# SYSTEM STATE
# ================================================================

armed = False

# ================================================================
# STARTUP — all outputs off
# ================================================================

led_green.value = False
led_red.value   = False
led_yel.value   = False
buzzer.duty_cycle = 0
coil_Am.value = False
coil_Ap.value = False
coil_Bp.value = False
coil_Bm.value = False

print("Security system starting... System is DISARMED.")

# ================================================================
# MAIN LOOP
# ================================================================

while True:

    # ============================================================
    # SECTION: ARM / DISARM BUTTON CHECK (GPIO 0)
    # ============================================================

    if btn_arm.value == False:                          # Button pressed (LOW)
        time.sleep(DEBOUNCE_ARM)                        # Wait 50ms debounce
        if btn_arm.value == False:                      # Confirm still pressed
            while btn_arm.value == False:               # Wait for release
                pass

            if armed == False:
                # --- ARM THE SYSTEM ---
                armed = True

                # Turn off all LEDs then turn on green
                led_green.value = False
                led_red.value   = False
                led_yel.value   = False
                led_green.value = True

                # --- CHIRP: 1000Hz → 1500Hz → 2000Hz ---
                buzzer.frequency  = 1000
                buzzer.duty_cycle = 32768
                time.sleep(0.05)

                buzzer.frequency  = 1500
                time.sleep(0.05)

                buzzer.frequency  = 2000
                time.sleep(0.05)

                buzzer.duty_cycle = 0       # Buzzer OFF

                print("System ARMED.")

            else:
                # --- DISARM THE SYSTEM ---
                armed = False

                # Turn off all LEDs
                led_green.value = False
                led_red.value   = False
                led_yel.value   = False

                # --- CHIRP: 1000Hz → 1500Hz → 2000Hz ---
                buzzer.frequency  = 1000
                buzzer.duty_cycle = 32768
                time.sleep(0.05)

                buzzer.frequency  = 1500
                time.sleep(0.05)

                buzzer.frequency  = 2000
                time.sleep(0.05)

                buzzer.duty_cycle = 0       # Buzzer OFF

                print("System DISARMED.")

    # ============================================================
    # SECTION: SENSOR CHECKS (only when armed)
    # ============================================================

    if armed == True:

        # --------------------------------------------------------
        # PIR MOTION SENSOR CHECK (GPIO 4)
        # --------------------------------------------------------

        if pir.value == True:                           # Motion detected

            print("PIR: Motion detected! Alarm triggered.")

            # a. Turn off all LEDs
            led_green.value = False
            led_red.value   = False
            led_yel.value   = False

            # b. Turn on red LED
            led_red.value = True

            # c. Wait for PIR and button state to settle
            time.sleep(PIR_SETTLE)

            # d. Turn on buzzer at 2000 Hz continuously
            buzzer.frequency  = 2000
            buzzer.duty_cycle = 32768

            # e. Wait until reset button (GPIO 5) is pressed
            print("PIR: Waiting for alarm reset...")

            while True:
                if btn_stop.value == False:             # Button pressed (LOW)
                    time.sleep(DEBOUNCE_STP)            # Wait 20ms debounce
                    if btn_stop.value == False:         # Confirm still pressed
                        while btn_stop.value == False:  # Wait for release
                            pass
                        break                           # Exit wait loop

                time.sleep(0.01)

            # f. Turn off buzzer
            buzzer.duty_cycle = 0

            # g. Turn on green LED
            led_green.value = False
            led_red.value   = False
            led_yel.value   = False
            led_green.value = True

            print("PIR: Alarm cleared.")

        # --------------------------------------------------------
        # LDR LIGHT SENSOR CHECK (GPIO 26 / GPIO 16)
        # Only runs if PIR did NOT detect motion
        # --------------------------------------------------------

        else:

            # --- Read lux from ADC ---
            raw     = ldr_adc.value                     # 0–65535
            voltage = (raw / 65535) * 3.3

            if voltage == 0:
                lux = 0.0
            else:
                r_ldr = 10000 * (3.3 - voltage) / voltage
                if r_ldr == 0:
                    lux = 9999.0
                else:
                    lux = 500 / (r_ldr / 1000)

            # --- Check if light is detected ---
            if ldr_dig.value == True or lux >= LUX_THRESHOLD:

                print("LDR: Light detected! Alarm triggered.")

                # a. Turn off all LEDs
                led_green.value = False
                led_red.value   = False
                led_yel.value   = False

                # b. Turn on yellow LED
                led_yel.value = True

                # c. Move stepper motor 90 degrees CLOCKWISE
                print("LDR: Moving stepper 90 degrees CW.")

                steps_to_move = int((90 / 360) * STEPS_PER_REV)  # = 50 steps

                step_count = 0
                while step_count < steps_to_move:
                    # Step 1: A-=1, A+=0, B+=1, B-=0
                    coil_Am.value = STEP_SEQUENCE[0][0]
                    coil_Ap.value = STEP_SEQUENCE[0][1]
                    coil_Bp.value = STEP_SEQUENCE[0][2]
                    coil_Bm.value = STEP_SEQUENCE[0][3]
                    time.sleep(STEP_DELAY)

                    # Step 2: A-=0, A+=1, B+=1, B-=0
                    coil_Am.value = STEP_SEQUENCE[1][0]
                    coil_Ap.value = STEP_SEQUENCE[1][1]
                    coil_Bp.value = STEP_SEQUENCE[1][2]
                    coil_Bm.value = STEP_SEQUENCE[1][3]
                    time.sleep(STEP_DELAY)

                    # Step 3: A-=0, A+=1, B+=0, B-=1
                    coil_Am.value = STEP_SEQUENCE[2][0]
                    coil_Ap.value = STEP_SEQUENCE[2][1]
                    coil_Bp.value = STEP_SEQUENCE[2][2]
                    coil_Bm.value = STEP_SEQUENCE[2][3]
                    time.sleep(STEP_DELAY)

                    # Step 4: A-=1, A+=0, B+=0, B-=1
                    coil_Am.value = STEP_SEQUENCE[3][0]
                    coil_Ap.value = STEP_SEQUENCE[3][1]
                    coil_Bp.value = STEP_SEQUENCE[3][2]
                    coil_Bm.value = STEP_SEQUENCE[3][3]
                    time.sleep(STEP_DELAY)

                    step_count = step_count + 1

                # Release all coils after CW move
                coil_Am.value = False
                coil_Ap.value = False
                coil_Bp.value = False
                coil_Bm.value = False

                # d. Turn on buzzer at 2000 Hz continuously
                buzzer.frequency  = 2000
                buzzer.duty_cycle = 32768

                # e. Wait until reset button (GPIO 5) is pressed
                print("LDR: Waiting for alarm reset...")

                while True:
                    if btn_stop.value == False:             # Button pressed (LOW)
                        time.sleep(DEBOUNCE_STP)            # Wait 20ms debounce
                        if btn_stop.value == False:         # Confirm still pressed
                            while btn_stop.value == False:  # Wait for release
                                pass
                            break                           # Exit wait loop

                    time.sleep(0.01)

                # f. Turn off buzzer
                buzzer.duty_cycle = 0

                # g. Turn on green LED
                led_green.value = False
                led_red.value   = False
                led_yel.value   = False
                led_green.value = True

                # h. Move stepper 90 degrees COUNTER-CLOCKWISE (reset position)
                print("LDR: Moving stepper 90 degrees CCW (reset).")

                step_count = 0
                while step_count < steps_to_move:
                    # Step 4 first (reverse order): A-=1, A+=0, B+=0, B-=1
                    coil_Am.value = STEP_SEQUENCE[3][0]
                    coil_Ap.value = STEP_SEQUENCE[3][1]
                    coil_Bp.value = STEP_SEQUENCE[3][2]
                    coil_Bm.value = STEP_SEQUENCE[3][3]
                    time.sleep(STEP_DELAY)

                    # Step 3: A-=0, A+=1, B+=0, B-=1
                    coil_Am.value = STEP_SEQUENCE[2][0]
                    coil_Ap.value = STEP_SEQUENCE[2][1]
                    coil_Bp.value = STEP_SEQUENCE[2][2]
                    coil_Bm.value = STEP_SEQUENCE[2][3]
                    time.sleep(STEP_DELAY)

                    # Step 2: A-=0, A+=1, B+=1, B-=0
                    coil_Am.value = STEP_SEQUENCE[1][0]
                    coil_Ap.value = STEP_SEQUENCE[1][1]
                    coil_Bp.value = STEP_SEQUENCE[1][2]
                    coil_Bm.value = STEP_SEQUENCE[1][3]
                    time.sleep(STEP_DELAY)

                    # Step 1: A-=1, A+=0, B+=1, B-=0
                    coil_Am.value = STEP_SEQUENCE[0][0]
                    coil_Ap.value = STEP_SEQUENCE[0][1]
                    coil_Bp.value = STEP_SEQUENCE[0][2]
                    coil_Bm.value = STEP_SEQUENCE[0][3]
                    time.sleep(STEP_DELAY)

                    step_count = step_count + 1

                # Release all coils after CCW move
                coil_Am.value = False
                coil_Ap.value = False
                coil_Bp.value = False
                coil_Bm.value = False

                # i. Log event
                print("LDR: Alarm cleared.")

    # Short pause before next loop iteration
    time.sleep(0.01)