// Shaiful Danish Bin Shaiful Razmiza, 52224122335.

// Include necessary libraries
#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <PubSubClient.h>  // MQTT library

// Blynk credentials
#define BLYNK_TEMPLATE_ID "TMPL6DQyQJdru"
#define BLYNK_TEMPLATE_NAME "ps3"
#define BLYNK_AUTH_TOKEN "mNZCOLlq3UvZIBXDzy8_VCXCEAqaqgtc"

// Wi-Fi credentials
char auth[] = BLYNK_AUTH_TOKEN;
char ssid[] = "Wokwi-GUEST";  // Wi-Fi SSID
char pass[] = "";         // Wi-Fi Password

// MQTT Broker settings
const char* mqtt_server = "broker.hivemq.com";  // Public MQTT broker
const int mqtt_port = 1883;
const char* mqtt_topic = "esp32/ldrStatus";

// Pin Definitions
const int ledPin = 5;     // Green LED
const int buzzerPin = 8;  // Buzzer
const int ldrSensor = 42; // LDR pin

WiFiClient espClient;         // Wi-Fi client
PubSubClient client(espClient);  // MQTT client

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

  // Initialize Wi-Fi and Blynk
  WiFi.begin(ssid, pass);
  Blynk.begin(auth, ssid, pass);

  // MQTT setup
  client.setServer(mqtt_server, mqtt_port);
  reconnectMQTT();

  // Pin setup
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ldrSensor, INPUT);
}

void loop() {
  // Blynk and MQTT tasks
  Blynk.run();
  if (!client.connected()) {
    reconnectMQTT();
  }
  client.loop();

  // LDR Sensor Reading
  int ldrValue = analogRead(ldrSensor);
  Serial.print("LDR Value: ");
  Serial.println(ldrValue);

  // Publish LDR value to MQTT topic
  char ldrValueString[10];
  itoa(ldrValue, ldrValueString, 10);
  client.publish(mqtt_topic, ldrValueString);

  // Control Green LED based on LDR Value
  if (ldrValue > 150) {
    digitalWrite(ledPin, HIGH);  // Turn on Green LED
    tone(buzzerPin, 500);
  } else {
    digitalWrite(ledPin, LOW);  // Turn off Green LED
    noTone(buzzerPin);
  }

  delay(1000);
}

// Reconnect to MQTT Broker
void reconnectMQTT() {
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
    if (client.connect("ESP32_Client")) {
      Serial.println("Connected to MQTT Broker!");
    } else {
      Serial.print("Failed with error code: ");
      Serial.print(client.state());
      delay(2000);
    }
  }
}