#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <DHT.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET    -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define DHTPIN 7       // Define the pin where the data pin of the DHT22 is connected
#define DHTTYPE DHT22  // Define the type of DHT sensor

DHT dht(DHTPIN, DHTTYPE);

const int buzzerPin = 6; // Define buzzer pin
const int redLEDPin = 8; // Define red LED pin
const int blueLEDPin = 9; // Define blue LED pin

void setup() {
  // Initialize OLED
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }
  display.display();
  delay(2000); // Pause for 2 seconds
  display.clearDisplay();

  // Initialize DHT sensor
  dht.begin();

  // Initialize pins
  pinMode(buzzerPin, OUTPUT);
  pinMode(redLEDPin, OUTPUT);
  pinMode(blueLEDPin, OUTPUT);

  // Initialize Serial
  Serial.begin(9600);
}

void loop() {
  // Read temperature and humidity from the DHT22 sensor
  float temperatureC = dht.readTemperature();
  float humidity = dht.readHumidity();

  // Check if any reads failed and exit early (to try again).
  if (isnan(temperatureC) || isnan(humidity)) {
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);
    display.print("Sensor error");
    display.display();
    Serial.println("Failed to read from DHT sensor!");
    delay(5000); // Wait 5 seconds before trying again
    return;
  }

  // Display temperature and humidity on the OLED
  display.clearDisplay();
  if (temperatureC >= 40) {
    // Display alert message
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);
    display.print("HOT INDEX ALERT");
    display.setCursor(0, 10);
    display.print("THE TEMP IS HIGH");
    tone(buzzerPin, 1000); // Activate buzzer
    digitalWrite(redLEDPin, HIGH); // Turn on red LED
    digitalWrite(blueLEDPin, LOW); // Turn off blue LED
  } else {
    // Display temperature and humidity
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);
    display.print("Temp: ");
    display.print(temperatureC);
    display.print(" C");
    
    display.setCursor(0, 10);
    display.print("Humidity: ");
    display.print(humidity);
    display.print(" %");
    
    noTone(buzzerPin); // Deactivate buzzer
    digitalWrite(redLEDPin, LOW); // Turn off red LED
    digitalWrite(blueLEDPin, HIGH); // Turn on blue LED
  }
  display.display();

  // Print to Serial Monitor for debugging
  Serial.print("Temperature: ");
  Serial.print(temperatureC);
  Serial.print(" C, Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");

  delay(5000); // Wait 5 seconds before next read
}