#include <PubSubClient.h>
#include <WiFi.h>
#include "DHTesp.h"


#define LED_BUILTIN 2

const int DHT_PIN = 15;

WiFiClient espClient;
PubSubClient mqttClient(espClient); //create an instance of espClient
DHTesp dhtSensor;

char tempAr[6]; //the maximum val we want is about 100.00 

void setup() {
  Serial.begin(115200);
  setupWifi();
  setupMqtt();
  dhtSensor.setup(DHT_PIN, DHTesp :: DHT22); //initialize the tempsensor

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


}

void loop() {
  //cjecks whether it is connected to the mqtt client
  if(!mqttClient.connected()){
    connectToBroker();
  }

  mqttClient.loop();


  updateTemperature();
  Serial.println(tempAr);
  mqttClient.publish("ENTC-TEMP", tempAr); //only accepts charater arrays
  delay(1000);


}
void setupWifi(){
  WiFi.begin("Wokwi-GUEST", "");

  while (WiFi.status() != WL_CONNECTED){
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

}

void setupMqtt(){
  mqttClient.setServer("test.mosquitto.org",1883);
  mqttClient.setCallback(receiveCallback);
}

void connectToBroker(){
  while(!mqttClient.connected()){
    Serial.println("Attempting MQTT connection.....");
    //if we don't want authentication, we can have any random name
    if(mqttClient.connect("ESP32-665959999")){
      Serial.println("Connected");
      mqttClient.subscribe("ENTC-ON-OFF");
    }else{
      Serial.print("Failed");
      Serial.print(mqttClient.state());
      delay(5000); //better to have a delay
    }
  }
}

void updateTemperature(){
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  //convert to a string with 2 decimal places
  String(data.temperature,2).toCharArray(tempAr,6);// the place where we need to store and the length of the array

}

void receiveCallback(char* topic, byte* payload, unsigned int length){
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("]");

  char payloadCharAr[length]; //varibale to store incoming data
  for (int i=0; i <length;i++){
    Serial.print((char)payload[i]);
    payloadCharAr[i] = (char)payload[i];
  }

  Serial.println();

  //comapre the topic with the given one
  //if the given 2 matches, the val will be zero
  if(strcmp(topic, "ENTC-ON-OFF") == 0){
    if(payloadCharAr[0] == '1'){
      digitalWrite(LED_BUILTIN , HIGH);
    }else{
      digitalWrite(LED_BUILTIN , LOW);
    }

  }

  }