from machine import Pin, PWM, ADC
import time


# ==========================================
# INPUTS
# ==========================================

# Potentiometer for speed
speed_pot = ADC(26)

# Slide switches
low_oil_switch = Pin(2, Pin.IN)
overheat_switch = Pin(3, Pin.IN)


# ==========================================
# OUTPUTS
# ==========================================

# Warning LED
led = Pin(15, Pin.OUT)

# Buzzer
buzzer = PWM(Pin(14))
buzzer.duty_u16(0)


# ==========================================
# BUZZER FUNCTION
# ==========================================

def beep():
    buzzer.freq(1200)
    buzzer.duty_u16(30000)

    time.sleep(0.2)

    buzzer.duty_u16(0)

    time.sleep(0.15)


# ==========================================
# VOICE GUIDANCE FUNCTION
# ==========================================

def voice_guidance(warning):

    print()

    if warning == "low_oil":
        print("VOICE: Low oil pressure detected.")
        print("VOICE: Reduce speed and stop the vehicle safely.")
        print("VOICE: Check the engine oil level.")

    elif warning == "engine_overheat":
        print("VOICE: Engine overheating detected.")
        print("VOICE: Reduce your speed.")
        print("VOICE: Stop the vehicle safely.")
        print("VOICE: Allow the engine to cool.")

    print()


# ==========================================
# CAN ENCODING FUNCTION
# ==========================================

def encode_vehicle_data(
    speed,
    low_oil_pressure=0,
    check_engine=0,
    brake_system=0,
    charging_fault=0,
    low_oil_level=0,
    abs_fault=0,
    low_tire_pressure=0,
    airbag=0,
    power_steering=0,
    stability_control=0,
    awd=0,
    engine_overheat=0
):

    # Byte 0 = Speed
    byte0 = speed

    # Byte 1 = warning group 1
    byte1 = (
        (low_oil_pressure << 0) |
        (check_engine << 1) |
        (brake_system << 2) |
        (charging_fault << 3) |
        (low_oil_level << 4) |
        (abs_fault << 5) |
        (low_tire_pressure << 6) |
        (airbag << 7)
    )

    # Byte 2 = warning group 2
    byte2 = (
        (power_steering << 0) |
        (stability_control << 1) |
        (awd << 2) |
        (engine_overheat << 3)
    )

    return byte0, byte1, byte2


# ==========================================
# PREVIOUS STATES
# ==========================================

last_low_oil = 0
last_overheat = 0


# ==========================================
# START MESSAGE
# ==========================================

print("================================")
print("VEHICLE SYSTEM STARTED")
print("================================")


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

while True:

    # --------------------------------------
    # READ SPEED
    # --------------------------------------

    raw_speed = speed_pot.read_u16()

    # Convert ADC value 0-65535 to 0-255 km/h
    speed = int(raw_speed * 255 / 65535)


    # --------------------------------------
    # READ WARNING SWITCHES
    # --------------------------------------

    low_oil_pressure = low_oil_switch.value()
    engine_overheat = overheat_switch.value()


    # --------------------------------------
    # CREATE CAN PAYLOAD
    # --------------------------------------

    can_data = encode_vehicle_data(
        speed=speed,
        low_oil_pressure=low_oil_pressure,
        engine_overheat=engine_overheat
    )


    # --------------------------------------
    # DISPLAY CAN INFORMATION
    # --------------------------------------

    print()
    print("--------------------------------")
    print("Speed:", speed, "km/h")
    print("CAN ID: 100")

    print(
        "CAN DATA: {:02X} {:02X} {:02X}".format(
            can_data[0],
            can_data[1],
            can_data[2]
        )
    )


    # --------------------------------------
    # WARNING LOGIC
    # --------------------------------------

    warning_active = False


    # LOW OIL PRESSURE
    if low_oil_pressure:

        print("WARNING: Low Oil Pressure")

        warning_active = True

        # Only activate when switch changes OFF -> ON
        if last_low_oil == 0:

            beep()
            beep()

            voice_guidance("low_oil")


    # ENGINE OVERHEAT
    if engine_overheat:

        print("WARNING: Engine Overheat")

        warning_active = True

        # Only activate when switch changes OFF -> ON
        if last_overheat == 0:

            beep()
            beep()

            voice_guidance("engine_overheat")


    # --------------------------------------
    # LED CONTROL
    # --------------------------------------

    if warning_active:

        led.value(1)

    else:

        led.value(0)


    # --------------------------------------
    # SAVE CURRENT SWITCH STATES
    # --------------------------------------

    last_low_oil = low_oil_pressure
    last_overheat = engine_overheat


    # --------------------------------------
    # WAIT
    # --------------------------------------

    time.sleep(1)