import time
import network
from machine import Pin
import dht
from umqtt.simple import MQTTClient

# -----------------------------
# Wi-Fi Configuration
# -----------------------------
SSID = "Wokwi-GUEST"
PASSWORD = ""

def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print("Connecting to Wi-Fi...")
        wlan.connect(SSID, PASSWORD)
        while not wlan.isconnected():
            time.sleep(0.5)
    print("Connected! IP:", wlan.ifconfig()[0])
    return wlan

wlan = connect_wifi()

# -----------------------------
# Hardware Setup
# -----------------------------
led = Pin(2, Pin.OUT)       # ESP32 onboard LED
sensor = dht.DHT22(Pin(15)) # DHT22 sensor on GPIO 15

# -----------------------------
# MQTT Configuration
# -----------------------------
MQTT_BROKER = "broker.hivemq.com"
CLIENT_ID = "esp32-wokwi-demo"
TOPIC_TEMP = b"esp32/iot/22UG3-0218temp"
TOPIC_HUM = b"esp32/iot/22UG3-0218hum"
TOPIC_STATUS = b"esp32/iot/22UG3-0218status"
TOPIC_CMD = b"esp32/iot/22UG3-0218cmd"

# Temperature threshold
TEMP_THRESHOLD = 28
# Publishing interval
PUBLISH_INTERVAL = 2

# -----------------------------
# MQTT Setup and Callback
# -----------------------------
mqtt = None

def mqtt_callback(topic, msg):
    topic = topic.decode()
    msg = msg.decode()
    print("Received:", topic, "->", msg)
    if msg.upper() == "ON":
        led.value(1)
        mqtt.publish(TOPIC_STATUS, b"LED turned ON")
        print("LED turned ON")
    elif msg.upper() == "OFF":
        led.value(0)
        mqtt.publish(TOPIC_STATUS, b"LED turned OFF")
        print("LED turned OFF")

def mqtt_connect():
    global mqtt
    print("Connecting to MQTT broker...")
    try:
        mqtt = MQTTClient(CLIENT_ID, MQTT_BROKER)
        mqtt.set_callback(mqtt_callback)
        mqtt.connect()
        mqtt.subscribe(TOPIC_CMD)
        mqtt.publish(TOPIC_STATUS, b"ESP32 connected and ready")
        print("Connected to MQTT broker")
    except Exception as e:
        print("Failed to connect to MQTT broker:", e)
        time.sleep(5)
        mqtt_connect()

mqtt_connect()

# -----------------------------
# Main Loop
# -----------------------------
while True:
    # Reconnect Wi-Fi if disconnected
    if not wlan.isconnected():
        print("Wi-Fi disconnected. Reconnecting...")
        wlan = connect_wifi()
        mqtt_connect()
    
    # Check for incoming MQTT messages
    try:
        mqtt.check_msg()
    except OSError as e:
        print("MQTT error:", e)
        mqtt_connect()
    
    # Read DHT22 sensor
    try:
        sensor.measure()
        temp = sensor.temperature()
        hum = sensor.humidity()
        
        # Only publish if temperature exceeds threshold
        if temp > TEMP_THRESHOLD:
            mqtt.publish(TOPIC_TEMP, str(temp).encode())
            mqtt.publish(TOPIC_HUM, str(hum).encode())
            mqtt.publish(TOPIC_STATUS, b"Data sent successfully")
            print("Published:", temp, "°C |", hum, "%")
            
            # Blink LED after publish
            led.value(1)
            time.sleep(0.2)
            led.value(0)
        else:
            print("Temperature below threshold:", temp, "°C. Not publishing.")
    
    except Exception as e:
        print("Sensor error:", e)
    
    # Wait for next interval
    time.sleep(PUBLISH_INTERVAL)