#include <DHT.h>
#include <PubSubClient.h>
#include <WiFi.h>
//#include <LiquidCrystal_I2C.h> not for now
//Relay
   const int relay=26;
//wifi connection
   const char *ssid = "Wokwi-GUEST";
   const char *pass = "";
//mqtt protocol declaration
   const char *mqtt_server = "broker.emqx.io";
   const char* mqtt_username= "emqx";
   const char* mqtt_password = "public";
   const int mqtt_port = 1883;

  
  //topic declaration for IOT MQTT Panel
  const char* tmp = "emqx/tempnecro";
  const char* hum = "emqx/humnecro";
  const char* led = "emqx/lednecro";
   
  // DHT22 Declaration
  #define DHTPIN 15
  #define DHTTYPE DHT22
  DHT dht(DHTPIN, DHTTYPE);

  //milis declaration
  long now = millis();
  long lastMeasure = 0; //initial value

  // WiFi & client publish declaraiton
  WiFiClient espClient;
  PubSubClient client(espClient);

  //Callback function (call the topic)
  void callback(char * topic, byte * payload, unsigned int length){
    Serial.print("Message arrived in topic");
    Serial.println(topic);
    Serial.print(". Message: ");

    String messageTemp;
    for(int i= 0;i < length;i++){
      Serial.print((char) payload[i]);
      messageTemp += (char)payload[i];
    }
    Serial.println();
  }

  //WiFi connection function
  void wifiConn() {
    //connecting to a wifi network
    WiFi.begin(ssid, pass);
     while(WiFi.status() != WL_CONNECTED) {
     delay(500);
     Serial.println("Still trying to connect to wifi...");
   }
    Serial.println("Connected");

    //connecting to a mqtt server
    client.setServer(mqtt_server, mqtt_port);
    client.setCallback(callback); //calling callback parameter

    // connecting process
    while(!client.connected()){
      String client_id = "esp32-client-";
      client_id += String(WiFi.macAddress());
      Serial.printf("The client %s connects to the public MQTT broker\n",
      client_id.c_str());

      //WiFI condition
      if(client.connect(client_id.c_str(), mqtt_username, mqtt_password)){
        Serial.println("Public EMQX MQTT broker connected");
      } else{ 
         Serial.print("failed with state");
         Serial.print(client.state());
         delay(2000);
       }
    }
   }

   void setup(){
     // Set software serial baud to 9600;
     Serial.begin(9600);
     pinMode(relay, OUTPUT);

     // calling wifiConn function
     wifiConn();

     //start and initialize dht object
     dht.begin();

   }

   void loop() {
    // Repeat sending sensor data
    client.loop();
/*untuk menjalankan waktu internal waktu internal setiap milli seconds pada esp32 secara
independent.
ketika millis di baca maka millis akan terus menghitung waktu walau pun esp32 nya sedang 
menjalankan prorgram yang lain 
*/
    now = millis();

    //scanning process
    if(now - lastMeasure > 2000){
      lastMeasure = now;
      float h = dht.readHumidity();
      float t = dht.readTemperature();
      float hic = dht.computeHeatIndex(t, h, false);

      //check if any reads failed and exit early (to try again);
      if(isnan(h) || isnan(t)){
        Serial.println("failed  to read from DHT  sensor!");
        return;
      } else{
        //client publish
        client.publish(hum, String(h).c_str());
        client.publish(tmp, String(t).c_str());
        //client.publish(led, String(relay).c_str())

        Serial.print(F("Humidity: "));
        Serial.print(h);
        Serial.print(F("% temperature: "));
        Serial.print(t);  
        Serial.print(" C ");

        boolean z;
        
        if((t > 28)&&(h > 60)){
          digitalWrite(relay, HIGH);
          int z = 1;
          Serial.println("Relay ON");
          client.publish(led, String(z).c_str());
        } else {
          digitalWrite(relay, LOW);
          int z = 0;
          Serial.print("Relay : OFF");
          client.publish(led, String(z).c_str());

         }
       }
     }
   }