print("Soil + DHTxx + MQTT | ESP32 | OLED")
print("BY FADZILAH (modified by ChatGPT for MQTT + DHT)")

from machine import Pin, I2C, ADC, PWM
import network, time, json
import ssd1306
import dht
from umqtt.simple import MQTTClient

# --- WIFI / MQTT ---
WIFI_SSID = "Wokwi-GUEST"   # <--- exact case for Wokwi
WIFI_PSWD = ""

# Use a public broker for Wokwi testing:
MQTT_BROKER = "broker.hivemq.com"   # or "test.mosquitto.org"
CLIENT_ID   = "esp32-soil-dht-01"
BASE        = "campus/greenhouse1"

TOPIC_PUB = f"{BASE}/state"
TOPIC_CMD = f"{BASE}/cmd"
TOPIC_RAW = f"{BASE}/raw"

# --- Soil calibration (tune for your sensor) ---
SOIL_RAW_DRY = 3135
SOIL_RAW_WET = 2165

# --- Pins ---
buzzer = PWM(Pin(26), freq=1, duty=0)
soil   = ADC(Pin(34))
try: soil.atten(ADC.ATTN_11DB)
except: pass

orange = Pin(32, Pin.OUT)
yellow = Pin(33, Pin.OUT)
green  = Pin(25, Pin.OUT)

i2c  = I2C(0, scl=Pin(22), sda=Pin(21))
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# Picture shows DHT22; use DHT22 here. If you use DHT11 hardware, change this line:
dhtx = dht.DHT22(Pin(27))

def wifi_connect():
    wlan = network.WLAN(network.STA_IF)
    if not wlan.active():
        wlan.active(True)
    if not wlan.isconnected():
        print("Connecting to Wi-Fi:", WIFI_SSID)
        wlan.connect(WIFI_SSID, WIFI_PSWD)
        t0 = time.ticks_ms()
        while not wlan.isconnected():
            if time.ticks_diff(time.ticks_ms(), t0) > 20000:
                print("Status:", wlan.status())
                raise RuntimeError("Wi-Fi connect timeout")
            time.sleep(0.2)
    print("Wi-Fi OK:", wlan.ifconfig())
    return wlan

mqtt = None
def on_mqtt_msg(topic, msg):
    try:
        data = json.loads(msg)
        if str(data.get("green_led", "")).lower() == "on":
            green.on()
        elif str(data.get("green_led", "")).lower() == "off":
            green.off()
    except Exception as e:
        print("MQTT cmd parse error:", e)

def mqtt_connect():
    global mqtt
    mqtt = MQTTClient(CLIENT_ID, MQTT_BROKER, keepalive=30)
    mqtt.set_callback(on_mqtt_msg)
    mqtt.connect()
    mqtt.subscribe(TOPIC_CMD)
    print("MQTT connected →", MQTT_BROKER, "| subscribed:", TOPIC_CMD)

def map_to_percent(raw, dry=SOIL_RAW_DRY, wet=SOIL_RAW_WET):
    if dry == wet: return 0
    r = max(min(raw, dry), wet)
    pct = int((dry - r) * 100 / (dry - wet))  # wet→100, dry→0
    return max(0, min(100, pct))

def show_oled(soil_pct, tC, h, status):
    oled.fill(0)
    oled.text("Soil Monitor", 0, 0)
    oled.text("Soil: {:>3}%".format(soil_pct), 0, 16)
    oled.text("Temp: {:>2}C".format("-" if tC is None else int(tC)), 0, 32)
    oled.text("Hum : {:>2}%".format("-" if h  is None else int(h )), 0, 48)
    oled.text(status, 80, 0)
    oled.show()

def set_outputs(status):
    if status == "WET":
        orange.on(); yellow.off(); green.off()
        buzzer.init(freq=400, duty=50); time.sleep(0.5)
        buzzer.init(freq=1, duty=0)
    elif status == "DRY":
        orange.off(); yellow.off(); green.on()
        buzzer.init(freq=2000, duty=50); time.sleep(0.5)
        buzzer.init(freq=1, duty=0)
    else:
        orange.off(); yellow.on(); green.off()
        buzzer.init(freq=1, duty=0)

def main():
    wifi_connect()
    mqtt_connect()

    while True:
        raw = soil.read()
        soil_pct = map_to_percent(raw)

        tC = None; h = None
        try:
            dhtx.measure()
            tC = dhtx.temperature()
            h  = dhtx.humidity()
        except Exception as e:
            print("DHT read err:", e)

        status = "WET" if soil_pct < 40 else ("DRY" if soil_pct > 60 else "IDEAL")
        set_outputs(status)
        show_oled(soil_pct, tC, h, status)

        payload = {
            "soil_percent": soil_pct,
            "soil_raw": raw,
            "status": status,
            "temp_c": tC,
            "humidity": h,
            "ts": time.time()
        }
        try:
            mqtt.check_msg()
            mqtt.publish(TOPIC_PUB, json.dumps(payload))
            mqtt.publish(TOPIC_RAW, str(raw))
        except Exception as e:
            print("MQTT publish error:", e)
            try: mqtt.disconnect()
            except: pass
            time.sleep(1)
            mqtt_connect()

        time.sleep(2)

try:
    main()
except Exception as e:
    print("Fatal error:", e)
    buzzer.init(freq=1, duty=0)