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

const int PIRinput = 17;  
int pirState = LOW;
#define Buzzer 4
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

int interval = 5000;
long previousMillis = 0;
int IntervalR = 3000;    // Interval at which to toggle LED3 (milliseconds)
long previousMillisR = 0;  
bool ledStateR = LOW;

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

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

WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_10145291"; // 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];
  }
}

void MQTTSubscribe() 
{
  client.subscribe("JCE/IoT");
}

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

}


void setup() 
{
  // put your setup code here, to run once:
  Serial.begin(115200);

  pinMode(PIRinput, INPUT);
  pinMode(23, OUTPUT);
  pinMode(18, OUTPUT);
  Serial.begin(9600);

  pinMode(Buzzer, OUTPUT);
  lcd.init();  //set LCD 
  lcd.backlight();

  setup_wifi();
  setup_MQTT();
}

void loop()
{
  const int IP = digitalRead(PIRinput);
  delay(100);
  long currentMillis = millis();
  if (currentMillis - previousMillis >= interval)
  {
    previousMillis = currentMillis;
    if (IP == 1)  // If motion is detected by the PIR sensor
    {
      String payload = String(PIRinput);
      client.publish("JCE/IoT", payload.c_str());
      digitalWrite(23, HIGH); 
      digitalWrite(18, LOW);
      if (pirState == LOW)  // Update pirState to indicate motion detection
        {
          Serial.println("Bin is opening!");
          lcd.clear();
          lcd.setCursor(1,0);
          lcd.print("Bin is opening");
          pirState = HIGH;
        }   
      else 
        {
          if (pirState == HIGH)  // Update pirState to indicate motion detection
            {
              Serial.println("Bin is closing...");
              lcd.clear();
              lcd.setCursor(1,0);
              lcd.print("Bin is closing");
              pirState = LOW;
              delay(3000);
              Serial.println("Bin is closed.");
              lcd.clear();
              lcd.setCursor(0,0);
              lcd.print("Bin is closed...");
              delay(500);
              digitalWrite(Buzzer, HIGH); //buzzer make sound
              delay(1000);
              digitalWrite(Buzzer, LOW);
            }
            digitalWrite(23, LOW);
            digitalWrite(18, HIGH);

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