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

//WiFi Setup
const char* ssid = "Wokwi-GUEST";     // WiFi ID
const char* password = "";            // WiFi Password
 
 //MQTT Setup
const char* mqttServer = "broker.hivemq.com";
const int mqttPort = 1883;
const char* clientID = "1650130907"; // Client ID username
const char* topic = "MES_DATA"; // Publish topic
// const char* mqttUserName = "bqzbdodo";
// const char* mqttPwd = "5oU2W_QN2WD8";

// Setting up WiFi and MQTT client
WiFiClient espClient;
PubSubClient client(espClient);

// DHT parameters
#define DHTTYPE    DHT22     // DHT 22
#define DHTPIN 12            // Pin12
DHT_Unified dht(DHTPIN, DHTTYPE);
uint32_t delayMS;

// Parameters for using non-blocking delay
unsigned long previousMillis = 0;
const long interval = 1000;
String msgStr = "";      // MQTT message buffer
float temp, hum;


void setup_wifi() {
  delay(10);
  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());
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect(clientID)) {
      Serial.println("MQTT connected");
      client.subscribe("MES/SUT/PUB");
      Serial.println("Topic Subscribed");
    }
    else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);  // wait 5sec and retry
    }
  }
}

void callback(char* topic, byte* payload, unsigned int length) {
  String data = "";
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
    data += (char)payload[i];
  }
  Serial.println("");
  Serial.println("-----------------------");
}

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

  //Setting MQTT server
  client.setServer(mqttServer, mqttPort); 
  client.setCallback(callback); // Define function which will be called when a message is received.
}

void loop() {
  if (!client.connected()) { // If client is not connected
    reconnect(); // Try to reconnect
  }
  client.loop();

  unsigned long currentMillis = millis();           // Read current time
  if (currentMillis - previousMillis >= interval) { // If current time - last time > 1 sec
    previousMillis = currentMillis;
    // Read temperature and humidity
    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("°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("MES_SUT", msg);
    msgStr = "";
    delay(1);
  }
  
}