#define BLYNK_TEMPLATE_ID "TMPL3LJ4dfKmk" //identifiers for a template in the Blynk app (used for the virtual devices).
#define BLYNK_TEMPLATE_NAME "Temperature Sensor"
#define BLYNK_AUTH_TOKEN "5UU61mGz1levQiAmZJ4T9C8LHL-2UEPo"// authentication token used to authorize the device to connect with the Blynk app.
#define BLYNK_PRINT Serial //directs the debug output to the Serial monitor, so you can see logs for debugging.

#include <WiFi.h> // Handles Wi-Fi connectivity for the ESP32.
#include <BlynkSimpleEsp32.h> // Enables Blynk integration on the ESP32.
#include <DHTesp.h>  // Library for DHT sensor and Library for reading temperature and humidity data from a DHT sensor 

char auth[] = BLYNK_AUTH_TOKEN;  // Auth Token for Blynk

char ssid[] = "Wokwi-GUEST";  // WiFi SSID
char pass[] = "";  // WiFi password

const int DHT_PIN = 15;  // DHT22 sensor is connected to gpio pin 15

// LED pins
byte LED_R = 26;
byte LED_Y = 27;
byte LED_G = 14;
byte LED_B = 12;

// Simulated temperature and heater state
float simulatedTemperature=25.0;  // Starting temperature (25°C)
float heatIncrement = 0.5;  // Temperature increase when heater is on
int heatStatus = 0;  // Heater status (0 = off, 1 = on)

DHTesp dht;  // DHT sensor object
BlynkTimer timer;  // An object of the BlynkTimer class that manages periodic tasks like sending sensor data.

// Function to simulate temperature changes and send sensor data
void sendSensor() {
  TempAndHumidity data = dht.getTempAndHumidity();

  // Simulate temperature behavior based on heater status
  if (heatStatus == 1) {
    simulatedTemperature+=heatIncrement;  // Increase temperature when heater is on
  } else {
    simulatedTemperature-=0.1;  // Gradual cooling when heater is off
    if (simulatedTemperature < 20.0) {  // Prevent temperature from going below 20°C
      simulatedTemperature = 20.0;
    }
  }



  // Print the simulated data to Serial Monitor
  Serial.print("Temperature: ");
  Serial.print(simulatedTemperature);
  Serial.println("°C");
  Serial.print("Humidity: ");
  Serial.print(data.humidity);
  Serial.println("%");

  // Send simulated temperature and humidity to Blynk
  Blynk.virtualWrite(V4, simulatedTemperature);  //sends the simulated temperature to virtual pin V4 in the Blynk app. 
  Blynk.virtualWrite(V5, data.humidity);  // sends the simulated humidity to virtual pin V5 in the Blynk app.
}

// Virtual pin V0 to control the red LED
BLYNK_WRITE(V0) {
  int value = param.asInt();
  digitalWrite(LED_R, value);
  Blynk.virtualWrite(V0, value);  // Optionally send LED status to Blynk app
}

// Virtual pin V1 to control the yellow LED
BLYNK_WRITE(V1) {
  int value = param.asInt();
  digitalWrite(LED_Y, value);
  Blynk.virtualWrite(V1, value);  // Optionally send LED status to Blynk app
}

// Virtual pin V2 to control the green LED
BLYNK_WRITE(V2) {
  int value = param.asInt();
  digitalWrite(LED_G, value);
  Blynk.virtualWrite(V2, value);  // Optionally send LED status to Blynk app
}

// Virtual pin V3 to control the blue LED
BLYNK_WRITE(V3) {
  int value = param.asInt();
  digitalWrite(LED_B, value);
  Blynk.virtualWrite(V3, value);  // Optionally send LED status to Blynk app
}

// Virtual pin V6 to control the heater (heat source)
BLYNK_WRITE(V6) {
  heatStatus = param.asInt();  // 0 = heater off, 1 = heater on
  Blynk.virtualWrite(V6, heatStatus);  // Send heat status to Blynk app
}

void setup() {
  Serial.begin(115200);  // Initialize Serial Monitor for debugging
  dht.setup(DHT_PIN, DHTesp::DHT22);  // Initialize DHT22 sensor
  pinMode(LED_R, OUTPUT);
  pinMode(LED_Y, OUTPUT);
  pinMode(LED_G, OUTPUT);
  pinMode(LED_B, OUTPUT);

  // Initialize Blynk with provided credentials
  Blynk.begin(auth, ssid, pass);
  
  // Set the timer interval to send sensor data every 1000ms (1 second)
  timer.setInterval(1000, sendSensor);
}

void loop() {
  Blynk.run();  // Keeps the Blynk connection alive and handles incoming and outgoing Blynk commands.
  timer.run();  // Runs the timer, which periodically calls sendSensor() to send temperature and humidity data.
}