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


char led_red = 23;
char led_green = 18;
char led_yellow = 19;

char led_red_state = LOW;
char led_green_state = LOW;
char led_yellow_state = LOW;

long led_red_previous_millis = 0;
long led_green_previous_millis = 0;
long led_yellow_previous_millis = 0;

int led_red_interval = 2000;
int led_green_interval = 1000;

const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* hostname = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_Win"; // yourStudentID must be unique
int PORTNUM = 1883;

void setup_wifi()
{
  WiFi.begin(ssid, password);
  while(WiFi.status() != WL_CONNECTED )
  {
    delay(1000);
    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 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 == "IOT/Win")
  {
    if(messageTemp == "On")
      digitalWrite(led_yellow, HIGH);
    else if (messageTemp == "Off")
      digitalWrite(led_yellow, LOW);
  }
}




void MQTTSubscribe() 
{
 client.subscribe("IOT/Win");

}

void setup_MQTT() 
{
  client.setServer(hostname, PORTNUM);
  client.setCallback(callback); 
}

void setup() {
  // put your setup code here, to run once:
  pinMode(led_red, OUTPUT);
  pinMode(led_green, OUTPUT);
  pinMode(led_yellow, OUTPUT);

  setup_wifi();
  setup_MQTT();
}

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

  long current_millis = millis();

  // green LED
  if (current_millis - led_green_previous_millis >= led_green_interval)
  {
    led_green_previous_millis = current_millis;

    // now reverse the led's state
    if (led_green_state == LOW)
      led_green_state = HIGH;
    else 
    {  
      led_green_state = LOW;
    }
    // control the led accordingly
    digitalWrite(led_green, led_green_state);
  }

  // red LED
  if (current_millis - led_red_previous_millis >= led_red_interval)
  {
    led_red_previous_millis = current_millis;

    // now reverse the led's state
    if (led_red_state == LOW)
    {
      led_red_state = HIGH;
      client.publish("IOT/Win", "On");
    }
    else
    { 
      led_red_state = LOW;
      client.publish("IOT/Win", "Off");
    }

    // control the led accordingly
    digitalWrite(led_red, led_red_state);
  }

}