#define BLYNK_TEMPLATE_ID "TMPL6VTlMTDap"
#define BLYNK_TEMPLATE_NAME "Air quality checker"
#define BLYNK_AUTH_TOKEN "mpuH49XAT_tKnllYlu-a0t7_DXOE_8C0"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

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

// MQ sensor pin
int mqPin = 34;  // GPIO34 (analog input)
int sensorValue;
int gasPercent;

// OLED settings
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

BlynkTimer timer;

void sendSensorData() {
  // Read analog value
  sensorValue = analogRead(mqPin);

  // Map to percentage (0-100%)
  gasPercent = map(sensorValue, 0, 4095, 0, 100);

  // Send to Blynk app on Virtual Pin V0
  Blynk.virtualWrite(V0, gasPercent);

  // Update OLED display
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(0,0);
  display.println("Air Quality");
  
  display.setTextSize(2);
  display.setCursor(0, 20);
  display.print(gasPercent);
  display.println("%");
  
  display.setTextSize(1);
  display.setCursor(0, 50);
  if(gasPercent < 20){
    display.println("Good");
  } else {
    display.println("Bad");
  }

  display.display();
}

void setup() {
  Serial.begin(115200);

  // Initialize OLED
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // I2C address 0x3C
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.clearDisplay();
  display.display();

  // Connect to Blynk
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);

  // Send data every second
  timer.setInterval(1000L, sendSensorData);
}

void loop() {
  Blynk.run();
  timer.run();
}