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

int YLED = 19;
int ledPin = 18; 
int ledState = LOW; 
long previousMillis = 0; 
int interval = 2000; 

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* hostname = "broker.hivemq.com";

//Initializes the espClient
WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_RM123";
int PORTNUM = 1883;

void setup_wifi()
{
  WiFi.begin(ssid, password);
  while(WiFi.status() != WL_CONNECTED )
  {
    delay(2000);
    Serial.print(".");
  }
  Serial.println();
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("Given IP by the router to ESP32 is ");
  Serial.println(WiFi.localIP());
}

void connectMQTT()
{
  while(!client.connected() )
  {
    Serial.println("Connecting to MQTT ...");
    if (client.connect(espClientName) ) //, mqttUser, mqttPassword) )
    {
      Serial.println("Connected");
      MQTTSubscribe();
    }
    else
    {
      Serial.print("Failed with state ");
      Serial.print(client.state() );
      delay(2000);
    }
  }
}
void setup_MQTT()
{
  client.setServer(hostname, PORTNUM);
  client.setCallback(callback);
}

void MQTTSubscribe() 
{
  // Subsccribe to your topics here
  client.subscribe("RM123/room/analog");  // example
  client.subscribe("RM123/room/analog"); 
}

void callback(String topic, byte* payload, unsigned int length)
{
  String messageTemp;
  Serial.print("Message received in topic: ");
  Serial.print(topic);
  Serial.print(" length is: ");
  Serial.println(length);
  Serial.print("Data received from broker: ");
  for (int i = 0; i<length; i++)
  {
    Serial.print( (char)payload[i] );
    messageTemp += (char)payload[i];
  }
  if (topic == "RM123/room/analog")
  {
    Serial.print("\Yellow LED is ");
    	if (messageTemp == "On")
		{
			Serial.print("On");
      digitalWrite(YLED, LOW);  
      Serial.print("\nYellow LED turned On ");      
		}
		else
		{
			Serial.print("Off");
      digitalWrite(YLED, HIGH); 
      Serial.print("\nYellow LED turned Off \n");      
		}
  }
  if (topic == "RM123/room/analog")
  {
    Serial.println(messageTemp);
  }
}

void setup()
{
// put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(ledPin, OUTPUT);
  pinMode(YLED, OUTPUT);
  setup_wifi();
  setup_MQTT();
}

void loop()
{
// put your main code here, to run repeatedly:
	long currentMillis = millis();
	if ( currentMillis - previousMillis >= interval)
	{
		previousMillis = currentMillis; // save the last time you blinked the LED
		if (ledState == LOW)
		{
			ledState = HIGH;
      client.publish("RM123/room/LED", "Off");
		}
		else
		{
			ledState = LOW;
      client.publish("RM123/room/LED", "On");      
		}
		digitalWrite(ledPin, ledState);
    
    int adcRes = analogRead(A5);
    char snum[10];  // Adjust the size based on the maximum expected value of adcRes
    itoa(adcRes, snum, 10);
    client.publish("RM123/room/analog",snum);
    Serial.print("The ADC reading (integer) is: ");
    Serial.println(adcRes);
    Serial.print("The ADC reading (string) is: ");
    Serial.println(snum);

    float  voltage = (float) adcRes * 3.3 / 4095;
    Serial.print("The voltage is ");
    Serial.println( voltage );

	}
  if ( !client.connected() )
  {
    connectMQTT();
  }
  client.loop();
}