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

// Relay Declaration
const int relay = 26; // << ini tambahkan

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

// MQTT Protocol Declaration
const char* mqtt_server = "broker.emqx.io"; 
const int mqtt_port = 1883;
const char* mqtt_username = "emqx";
const char* mqtt_password = "public";

// Topic Declaration for IOT MQTT Panel
const char* temperatureTopic = "emqx/suhulana";
const char* humidityTopic = "emqx/humdlana";
const char* ledTopic = "emqx/ledlana"; // << ini tambahkan

// DHT22 Declaration
#define DHTPIN 15
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

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

// WiFi & Client Publish Declaration
WiFiClient espClient;
PubSubClient client(espClient);

// Callback function (to 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; // <<< ini tambahkan
    for (int i = 0; i < length; i++) {
        Serial.print((char) payload[i]);
        messageTemp += (char)payload[i];    // <<< ini tambahkan
    }
    Serial.println();
}

// WiFI connection function
void wifiConn(){
    // Connecting to a WiFi network
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        //delay(1000);
        Serial.println("Connecting to WiFi..");
    }
    Serial.println("Connected to the Wi-Fi network");
    
    // Connecting to a mqtt server
    client.setServer(mqtt_server, mqtt_port); 
    client.setCallback(callback);    // Calling callback parameter 
    
    // Connecting Proccess
    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); // << tambahkan ini

    // Calling wifiConn function
    wifiConn(); // Ini cara memanggil fungsi wifi Conn

    // Start and initialize the dht object 
    dht.begin();
}

void loop() {
  // Repeat sending sensor data
  client.loop();
  
  /* Fungsi Millis untuk menjalankan waktu internal setiap milli seconds 
    pada ESP32 secara independent
    ketika millis di baca maka millis akan terus 
    menghitung waktu walaupun ESP32nya sedang menjalankan 
    program 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(humidityTopic, String(h).c_str());
        client.publish(temperatureTopic, String(t).c_str());

        Serial.print(F("Humidity: "));
        Serial.print(h);
        Serial.print(F("% Temperature: "));
        Serial.print(t);
        Serial.println(" *C ");
        
        boolean z; // << ini tambahkan
        if((t > 28)&&(h <= 60)){
          digitalWrite(relay, LOW);
          int z = 0;
          Serial.print("Relay: OFF ");
          client.publish(ledTopic, String(z).c_str());
        }
        else if((t > 23)&&(h > 60)){
          digitalWrite(relay, HIGH);
          int z = 1;
          Serial.print("Relay: ON ");
          client.publish(ledTopic, String(z).c_str());
        }
        else{
          digitalWrite(relay, LOW);
          int z = 0;
          Serial.print("Relay: OFF ");
          client.publish(ledTopic, String(z).c_str());
        }
    }
  }
}


/* Exercise: 
  1. if t > 28 and h <= 60, then Relay OFF, Suhu Dingin
  2. if t > 23 and t <= 28, then Relay OFF, Suhu Dingin 
  3. if t < 23 and h > 60, then Relay ON, Suhu Panas
*/