// code for temperature and humidity monitoring using nodered dashboard

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

// connect to the router, use the credentials of your router, for simulation 
// we use these values
const char* ssid = "Wokwi-GUEST";
const char* password = "";
// In case you are using a Raspberry Pi use its IP address so as to connect to
// the MQTT broker, for simulation we use this
const char* mqtt_server = "test.mosquitto.org";// MQTT broker
char* my_topic2 = "/IoT1/temp";// topic2: sensor-temerature
char* my_topic3 = "/IoT1/hum";// topic3: sensor-humidity
 
WiFiClient espClient;
PubSubClient client(espClient);

DHT dht(4, DHT22);

void setup() {

  Serial.begin(115200); // Initialize serial communication for debugging
  //myservo.attach(5); // Attach the servo to GPIO pin 5
  setup_wifi(); 
  client.setServer(mqtt_server, 1883); // Set the MQTT broker server and port
  //client.setCallback(callback); // Set the callback function for incoming MQTT messages
  dht.begin();
  delay(2000);
}
// Connect to the Wi-Fi network using the provided credentials
void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP()); // Print the local IP address of the ESP32 once connected
}
// Process incoming MQTT message and control the servo motor
//void callback(char* topic, byte* payload, unsigned int length) {   
  //if (topic = my_topic2){
    
  //} 
//}
// Attempt to reconnect to the MQTT broker if the connection is lost
void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESPClient")) {
      Serial.println("connected");
      client.subscribe(my_topic2);
      client.subscribe(my_topic3);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds"); 
      delay(5000);
    }
  }
}
void loop() {
  // Check MQTT connection and process incoming messages
  if (!client.connected()) {
    reconnect();
  }
  client.loop(); 
  delay(100); // Add a delay to avoid flooding the MQTT broker with messages
  float temp = dht.readTemperature();
  float humidity = dht.readHumidity();
  Serial.print("Temp : ");
  Serial.print(temp);
  Serial.println(" C ");
  Serial.print("Humidity : ");
  Serial.print(humidity);
  Serial.println(" % ");
  String messaget = String(temp);
  String messageh = String(humidity);
  client.publish("/IoT1/temp", messaget.c_str());
  client.publish("/IoT1/hum", messageh.c_str());
  delay(200);
 
}