#include <Adafruit_ESP8266.h> // Use <WiFi.h> for ESP32
#include <PubSubClient.h>
#include <DHT.h>
#include <ArduinoJson.h>
#include <WiFi.h>

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// MQTT Broker settings
const char* mqtt_broker = "broker.mqttdashboard.com";
const char* mqtt_topic = "wokwi-weather";
const char* mqtt_client_id = "arduino-weather-demo"; // Changed to avoid conflict
const char* mqtt_user = "";
const char* mqtt_password = "";

// DHT Sensor setup
#define DHTPIN 21        // Pin where DHT22 is connected (GPIO 15)
#define DHTTYPE DHT22    // DHT22 sensor type
DHT dht(DHTPIN, DHTTYPE);

// WiFi and MQTT clients
WiFiClient espClient;
PubSubClient client(espClient);

// Variable to store the previous weather data
String prevWeather = "";

void setup() {
  Serial.begin(115200); // Start serial communication
  dht.begin();          // Initialize DHT sensor

  // Connect to WiFi
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println(" Connected!");

  // Connect to MQTT broker
  client.setServer(mqtt_broker, 1883); // Default MQTT port
  connectToMQTT();
}

void connectToMQTT() {
  Serial.print("Connecting to MQTT server... ");
  while (!client.connected()) {
    if (client.connect(mqtt_client_id, mqtt_user, mqtt_password)) {
      Serial.println("Connected!");
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" Retrying in 5 seconds...");
      delay(5000);
    }
  }
}

void loop() {
  if (!client.connected()) {
    connectToMQTT();
  }
  client.loop(); // Handle MQTT client tasks

  // Read sensor data
  Serial.print("Measuring weather conditions... ");
  float temp = dht.readTemperature();    // Read temperature in Celsius
  float humidity = dht.readHumidity();   // Read humidity in %

  // Check if readings are valid
  if (isnan(temp) || isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
    delay(1000);
    return;
  }

  // Create JSON object
  StaticJsonDocument<200> doc;
  doc["temp"] = temp;
  doc["humidity"] = humidity;

  // Serialize JSON to string
  char message[256];
  serializeJson(doc, message);

  // Compare with previous message
  String currentWeather = String(message);
  if (currentWeather != prevWeather) {
    Serial.println("Updated!");
    Serial.print("Reporting to MQTT topic ");
    Serial.print(mqtt_topic);
    Serial.print(": ");
    Serial.println(message);

    // Publish the message
    client.publish(mqtt_topic, message);
    prevWeather = currentWeather;
  } else {
    Serial.println("No change");
  }

  delay(1000); // Wait 1 second before next reading
}