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

# WiFi credentials
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASS = ""

# MQTT broker details
MQTT_BROKER = "broker.hivemq.com"
MQTT_PORT = 1883
MQTT_TOPIC = "aiot/dht22"

# Initialize DHT22
sensor = dht.DHT22(Pin(15))

# Connect to WiFi
def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(WIFI_SSID, WIFI_PASS)
    print("Connecting to WiFi...", end="")
    while not wlan.isconnected():
        print(".", end="")
        time.sleep(0.5)
    print("\nConnected:", wlan.ifconfig())
    return wlan

# Connect to MQTT broker
def connect_mqtt():
    client_id = "ESP32_" + str(time.ticks_ms())
    client = MQTTClient(client_id, MQTT_BROKER, port=MQTT_PORT)
    client.connect()
    print("Connected to MQTT broker:", MQTT_BROKER)
    return client

# Main program
def main():
    wlan = connect_wifi()
    client = connect_mqtt()

    while True:
        try:
            sensor.measure()
            temp = sensor.temperature()
            hum = sensor.humidity()
            
            # Create JSON message
            data = json.dumps({"temperature": temp, "humidity": hum})
            
            # Publish message
            client.publish(MQTT_TOPIC, data)
            print("Published:", data)

        except OSError as e:
            print("Sensor error:", e)
        
        time.sleep(5)  # Publish every 5 seconds

# Run main loop
main()