#include <Adafruit_Sensor.h>
#include <DHT_U.h>
#include <WiFi.h>
#include <PubSubClient.h>

//defining pins
#define DHTPIN 16
#define LED 26

//DHT parameters
#define DHTType DHT22 //DHT11
DHT_Unified dht (DHTPIN, DHTType);
uint32_t delayMs;

//define parameters wifi
//const char* ssid = "Wokwi-GUEST";        //setting your AP SSID
//const char* password = " ";              //setting password AP PSK

const char* mqttserver = "broker.hivemq.com";
const char* topic = "TempRuhaida";         //publish topic
const char* clientID = "ESP32-wokwi";

//parameters for using non-blocking delay

unsigned long previousMillis = 0;
const long interval = 1000;

String msgStr = "";                   // MQTT message buffer
float temp, hum;

//setting up wifi and MQTT Client

WiFiClient espClient;
PubSubClient client(espClient);

//set up function for MQTT
void setup_wifi (){
  delay(10);
  WiFi.begin ("Wokwi-GUEST", "", 6);
  while (WiFi.status()!= WL_CONNECTED){
    delay (500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi Connected");
  Serial.println("IP address: ");
  Serial.println("WiFi.localIP()");
}

void reconnect(){
  while (!client.connected()){
    if (client.connect(clientID)){
      Serial.println("MQTT Connected");
      client.subscribe("LEDRuhaida");
      Serial.println("Topic Subscribed");
    }
    else {
      Serial.println("failed, rc=");
      Serial.print(client.state());
      Serial.println("try again in 5 seconds");
      delay(5000);
    }
  }
}
//subscribe callback
void callback (char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived in topic: ");
  Serial.println(topic);
  Serial.print("Message: ");
  String data = "";
  for (int i = 0; i < length; i++) {
    Serial.print ((char)payload[i]);
    data += (char)payload[i];
  }
  Serial.println();
  Serial.print("Message size:  ");
  Serial.println(length);
  Serial.println();
  Serial.println("...................");
  Serial.println(data);

  if (String(topic)== "LEDRuhaida"){
    if (data == "ON") {
      Serial.println("LED");
      digitalWrite(LED, HIGH);
  }
  else {
    digitalWrite(LED, LOW);
  }
}
}

//set up function

void setup() {
Serial.begin(115200);

//initialize device
dht.begin();

//get temperature sensor details
sensor_t sensor;
dht.temperature().getSensor(&sensor);
dht.humidity().getSensor(&sensor);

pinMode(LED, OUTPUT);
digitalWrite(LED, LOW);

setup_wifi();
client.setServer (mqttserver, 1883);     //setting MQTT Server
client.setCallback(callback);

}

void loop() {
  if (!client.connected()) {            //if client is not connected
    reconnect();                        //Try to reconnect
  }
  client.loop();
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    //Read Temperature and Humudity
    sensors_event_t event;
    dht.temperature().getEvent(&event);
    if (isnan(event.temperature)) {
      Serial.println(F("Error reading temperature!"));
    
    }
    else{
      Serial.print(F("Temperature: "));
      temp = event.temperature;
      Serial.print(temp);
      Serial.println(F("deg C"));
    }
    //Get humidity event and print its value
    dht.humidity().getEvent(&event);
    if (isnan(event.relative_humidity)) {
      Serial.println(F("Error reading humidity!"));
    }
    else {
      Serial.print(F("Humidity: "));
      hum = event.relative_humidity;
      Serial.print(hum);
      Serial.println(F("%"));
    }
    msgStr = String(temp) + "," + String(hum) + ",";
    byte arrSize = msgStr.length() + 1;
    char msg[arrSize];
    Serial.print("Publish Data:  ");
    Serial.println(msgStr);
    msgStr.toCharArray(msg, arrSize);
    client.publish(topic, msg);
    msgStr = "";
    delay(1);

  }
}