#include <WiFi.h>
#include <PubSubClient.h>
#include <DHT.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

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

// MQTT Broker
const char* mqtt_broker = "broker.emqx.io";
const char* topic = "esp32/section";
const int mqtt_port = 1883;

// MQTT and DHT configuration
WiFiClient espClient;
PubSubClient client(espClient);
DHT dht(4, DHT22); // DHT sensor on GPIO 4

// LCD configuration
LiquidCrystal_I2C lcd(0x27, 16, 2); // Adjust 0x27 to your LCD I2C address

void setup() {
  // Initialize Serial Monitor
  Serial.begin(115200);

  // Initialize LCD
  lcd.init();
  lcd.backlight();
  
  // Show "Connecting..." on LCD while connecting to WiFi
  lcd.setCursor(0, 0);
  lcd.print("Connecting...");
  
  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi!");
  lcd.clear();
  lcd.print("WiFi Connected");

  // Connect to MQTT Broker
  client.setServer(mqtt_broker, mqtt_port);
  while (!client.connected()) {
    String client_id = "esp32-" + String(WiFi.macAddress());
    if (client.connect(client_id.c_str())) {
      Serial.println("Connected to MQTT Broker!");
      lcd.setCursor(0, 1);
      lcd.print("MQTT Connected");
    } else {
      Serial.println("MQTT connection failed. Retrying...");
      delay(2000);
    }
  }

  // Initialize DHT sensor
  dht.begin();
  delay(2000); // Delay to stabilize
  lcd.clear();
  lcd.print("Setup Complete");
  delay(2000); // Show setup complete message for a short time
}

void loop() {
  client.loop(); // Handle MQTT client connection

  // Read temperature and humidity
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  // Check if readings are valid
  if (!isnan(temperature) && !isnan(humidity)) {
    // Publish data to MQTT
    String payload = String("{\"temperature\":") + temperature + ",\"humidity\":" + humidity + "}";
    client.publish(topic, payload.c_str());
    Serial.println("Data published: " + payload);

    // Display data on LCD
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Temp: " + String(temperature) + " C");
    lcd.setCursor(0, 1);
    lcd.print("Humidity: " + String(humidity) + " %");
  } else {
    // Handle sensor error
    Serial.println("Failed to read from DHT sensor!");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error!");
  }

  // Delay before the next reading
  delay(5000); // 5 seconds
}