// SMART TRASH BIN COLLECTION IOT PROJECT USING ULTRASONIC DISTANCE SENSOR HC-SR04
#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>

#define echoPin 14
#define trigPin 12

int Rled = 19;
int Gled = 18;

long duration;
int distance;

// Codes to connect to HiveMQTT
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* hostname = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_8828880c"; // change
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) )
    {
      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 == "PIOT/BINSTATUS")
  {

  }*/
}

void MQTTSubscribe()
{
  client.subscribe("PIOT/BINSTATUS");
}

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

void setup()
{
  Serial.begin(115200);
  setup_wifi();
  setup_MQTT();
  pinMode(Rled, OUTPUT);
  pinMode(Gled, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  delay(500);
}

void loop()
{
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10); 

  digitalWrite(trigPin, LOW); 

  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.0344 / 2;

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  delay(100);

  if (distance < 120)
  {
    digitalWrite(Gled, LOW);
    digitalWrite(Rled, HIGH);
    Serial.println("Bin is not full");
    client.publish("PIOT/BINSTATUS","Bin is not full");
    delay(500);
  };

  if (distance > 121)
  {
    digitalWrite(Gled, HIGH);
    digitalWrite(Rled, LOW);
    Serial.println("Bin is full");
    client.publish("PIOT/BINSTATUS","Bin is full");
    delay(500);
  }

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