/*	Group Assignment - 2 Sensors
* Group Members: 
* Name 1:	NG YONG XIANG (8587093A)
* Name 2:
* Name 3:
* Room: DEE 1
*/ 

#include <OneWire.h>
#include <DallasTemperature.h>
#include <NewPing.h>
#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>

// HC-SR04 Ultrasonic Sensor pins
#define TRIG_PIN 12
#define ECHO_PIN 14
#define MAX_DISTANCE 400  // Max distance in cm

// Pin configuration
const int oneWireBus = 27; // DS18B20 data pin
const int buzzerPin = 16; // Buzzer pin

#define RLED_PIN 17 // RED LED pins

// Setup a oneWire instance to communicate with any OneWire devices
OneWire oneWire(oneWireBus);
DallasTemperature sensors(&oneWire);

// Initialize NewPing
NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE);

// WiFi and MQTT configuration
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* hostname = "broker.hivemq.com";
WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_JonasNG";
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];
  }

  // Handle your topics and payload here
  if (topic == "IOT/temperature") 
  {
     Serial.print("Turning to ");
    if (messageTemp == "open")
    {
      digitalWrite(buzzerPin, HIGH);
      Serial.println("buzzer open");
    }
    else if (messageTemp == "close")
    {
      digitalWrite(buzzerPin, LOW);
      Serial.println("buzzer close");
    }
    else if (messageTemp == "on")
    {
      digitalWrite(RLED_PIN, HIGH);
      Serial.println("led on");
    }
    else if (messageTemp == "off")
    {
      digitalWrite(RLED_PIN, LOW);
      Serial.println("led off");
    }
  }
}

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

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

void setup() 
{
  Serial.begin(9600);
  delay(5000);

  pinMode(buzzerPin, OUTPUT);
  sensors.begin();

  pinMode(RLED_PIN, OUTPUT);

  Serial.println("System Initialized"); 

  setup_wifi();
  setup_MQTT();
}

volatile bool RESET1 = false;

void RESET()
{
  RESET1 = true;
}

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

  // Read temperature from DS18B20
  sensors.requestTemperatures();
  float temperatureC = sensors.getTempCByIndex(0);

  if(RESET1)
    {
      digitalWrite(buzzerPin, LOW);
    }
    else
    {
      digitalWrite(buzzerPin, HIGH);
    }

  // Print temperature to Serial Monitor
  Serial.print("Temperature: ");
  Serial.print(temperatureC);
  Serial.println(" °C");

  // Publish triggers based on temperature readings
  if (temperatureC >= 50) 
  {
    client.publish("IOT/temperature", "open");
  } 
  else if (temperatureC < 50) 
  {
    client.publish("IOT/temperature", "close");
  }


  // Measure distance from HC-SR04
  delay(50);  // Small delay before reading again
  int distance = sonar.ping_cm();  // Measure distance in cm

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

  // If distance is less than 200mm (20 cm), turn on LED
  if (distance > 0 && distance < 20)
  {
    client.publish("IOT/temperature", "on");
  }
  else
  {
     client.publish("IOT/temperature", "off");
  }

  delay(1000);
}