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

#define SCREEN_WIDTH 128  // OLED display width
#define SCREEN_HEIGHT 64  // OLED display height
#define OLED_RESET    -1  // Reset pin (-1 if using I2C)

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// MQ Sensor Pins
#define MQ_BEFORE_PIN 12  // Pin for MQ Before sensor
#define MQ_AFTER_PIN 14  // Pin for MQ After sensor

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

    // Initialize OLED display
    if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Check OLED I2C Address (0x3C or 0x3D)
        Serial.println(F("SSD1306 allocation failed"));
        for (;;);
    }

    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(0, 0);
    display.println("MQ Sensor Test");
    display.display();
    delay(2000);
}

void loop() {
    // Simulated readings from Wokwi (Replace with real MQ sensor values)
    float mq_before = analogRead(MQ_BEFORE_PIN);
    float mq_after = analogRead(MQ_AFTER_PIN);

    // Calculate Efficiency
    float efficiency = 0;
    if (mq_before > 0) {
        efficiency = ((mq_before - mq_after) / mq_before) * 100;
    }

    // Clear OLED display and update values
    display.clearDisplay();
    
    display.setCursor(0, 0);
    display.println("Sensor Readings:");

    display.setCursor(0, 15);
    display.print("MQ Before: ");
    display.println(mq_before);

    display.setCursor(0, 30);
    display.print("MQ After: ");
    display.println(mq_after);

    display.setCursor(0, 45);
    display.print("Efficiency: ");
    display.print(efficiency);
    display.println(" %");

    display.display(); // Update OLED display

    // Print values to Serial Monitor
    Serial.print(mq_before);
    Serial.print(",");
    Serial.print(mq_after);
    Serial.print(",");
    Serial.println(efficiency);

    delay(2000);  // Update every 2 seconds
}