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

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

#define CO2_SENSOR_PIN 34  // Simulated CO2 Sensor
#define TEMP_SENSOR_PIN 35  // Simulated Temperature Sensor
#define RED_LED 27          // High Pollution Alert LED
#define GREEN_LED 26        // Normal Air Quality LED
#define BUZZER 25           // Alarm for High Pollution

void setup() {
    Serial.begin(115200);
    
    pinMode(RED_LED, OUTPUT);
    pinMode(GREEN_LED, OUTPUT);
    pinMode(BUZZER, OUTPUT);
    
    digitalWrite(RED_LED, LOW);
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(BUZZER, LOW);
    
    // Initialize OLED display
    if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
        Serial.println("SSD1306 allocation failed");
        for(;;);
    }
    
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(0, 0);
    display.println("Air Quality Monitoring");
    display.display();
    delay(2000);
}

void loop() {
    int co2Value = analogRead(CO2_SENSOR_PIN);  // Read CO2 sensor value
    int tempValue = analogRead(TEMP_SENSOR_PIN);  // Read temperature sensor value
    
    // Convert potentiometer values (0-4095) to realistic units
    float co2Level = map(co2Value, 0, 4095, 400, 2000);  // 400ppm to 2000ppm
    float temperature = map(tempValue, 0, 4095, 20, 50);  // 20°C to 50°C
    
    Serial.print("CO2 Level: "); Serial.print(co2Level); Serial.println(" ppm");
    Serial.print("Temperature: "); Serial.print(temperature); Serial.println(" °C");
    
    // Update OLED Display
    display.clearDisplay();
    display.setCursor(0, 10);
    display.print("CO2: "); display.print(co2Level); display.println(" ppm");
    display.print("Temp: "); display.print(temperature); display.println(" C");
    
    // Fire alert condition
    if (co2Level > 1000) {  // Pollution threshold
        digitalWrite(RED_LED, HIGH);  // Turn on warning LED
        digitalWrite(GREEN_LED, LOW);  // Turn off normal LED
        digitalWrite(BUZZER, HIGH);  // Sound alarm
        display.println("⚠ High Pollution ⚠");
    } else {
        digitalWrite(RED_LED, LOW);
        digitalWrite(GREEN_LED, HIGH);
        digitalWrite(BUZZER, LOW);
        display.println("Air Quality: Normal");
    }
    
    display.display();
    delay(2000);  // Update every 2 seconds
}