from machine import Pin
import time
import utime

print("Hello, Pi Pico")

# Ultrasonik HC-SR04
trigger = Pin(2, Pin.OUT)
echo = Pin(3, Pin.IN)

# LED
led_hijau = Pin(6, Pin.OUT)
led_merah = Pin(7, Pin.OUT)

# Relay ultrasonik
relay2 = Pin(4, Pin.OUT)

# Relay MQ2
relay_mq2 = Pin(5, Pin.OUT)

# MQ2 sensor (digital pin)
DO_PIN = Pin(26, Pin.IN)

# Konstanta batas jarak
MIN_LEVEL = 10
MAX_LEVEL_HIJAU = 20
MAX_LEVEL_MERAH = 40

# State relay
relay2_aktif = False
relay_mq2_aktif = False

# Fungsi baca jarak ultrasonik
def read_distance():
    trigger.low()
    time.sleep_us(2)
    trigger.high()
    time.sleep_us(10)
    trigger.low()

    while echo.value() == 0:
        signal_off = time.ticks_us()
    while echo.value() == 1:
        signal_on = time.ticks_us()

    time_passed = signal_on - signal_off
    distance = (time_passed * 0.0343) / 2  # dalam cm
    return distance

# Loop utama
while True:
    try:
        # ====== Baca sensor ======
        jarak = read_distance()
        gas_state = DO_PIN.value()

        print("Jarak: {:.1f} cm".format(jarak))

        # ====== Logika 10 - 20 cm ======
        if MIN_LEVEL <= jarak <= MAX_LEVEL_HIJAU:
            led_hijau.value(1)
            led_merah.value(0)

            # Jika gas terdeteksi → aktifkan relay_mq2
            if gas_state == 0 and not relay_mq2_aktif:
                relay_mq2.value(1)
                relay_mq2_aktif = True
                print("Status: 10-20cm + GAS DETECTED → relay_mq2 ON")

            # Jika gas tidak terdeteksi → relay_mq2 tetap OFF
            elif gas_state == 1 and not relay_mq2_aktif:
                relay_mq2.value(0)
                relay_mq2_aktif = False
                print("Status: 10-20cm + NO GAS → relay_mq2 OFF")

            # Jika relay_mq2 sudah aktif → tetap aktif sampai JARAK > 20 cm
            elif relay_mq2_aktif:
                print("Status: relay_mq2 tetap AKTIF")

            # relay2 OFF di kondisi ini
            relay2.value(0)
            relay2_aktif = False

        # ====== Logika 21 - 40 cm ======
        elif MAX_LEVEL_HIJAU < jarak <= MAX_LEVEL_MERAH:
            led_hijau.value(0)
            led_merah.value(1)

            # Aktifkan relay2 jika belum aktif
            if not relay2_aktif:
                relay2.value(1)
                relay2_aktif = True
                print("Status: 21-40cm → relay2 ON")

            # relay_mq2 OFF di kondisi ini
            relay_mq2.value(0)
            relay_mq2_aktif = False

        # ====== Reset relay2 jika kembali ke bawah 10cm ======
        elif jarak < MIN_LEVEL:
            led_hijau.value(0)
            led_merah.value(0)

            # Reset relay2 jika aktif
            if relay2_aktif:
                relay2.value(0)
                relay2_aktif = False
                print("Status: <10cm → relay2 OFF")

            # relay_mq2 OFF jika jarak < 10cm
            relay_mq2.value(0)
            relay_mq2_aktif = False

        # ====== Di luar range lain → semua OFF ======
        else:
            led_hijau.value(0)
            led_merah.value(0)

            relay2.value(0)
            relay2_aktif = False

            relay_mq2.value(0)
            relay_mq2_aktif = False

            print("Status: Di luar range → Semua OFF")

    except Exception as e:
        print("Error:", e)

    time.sleep(1)