#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 CO_SENSOR_PIN 34    // Simulated CO Sensor
#define NO2_SENSOR_PIN 35   // Simulated NO2 Sensor
#define AQ_SENSOR_PIN 32    // Simulated Air Quality 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 Pollution Monitoring");
    display.display();
    delay(2000);
}

void loop() {
    int coValue = analogRead(CO_SENSOR_PIN);  // Read CO sensor value
    int no2Value = analogRead(NO2_SENSOR_PIN);  // Read NO2 sensor value
    int aqValue = analogRead(AQ_SENSOR_PIN);  // Read air quality sensor
    
    // Simulated conversion of sensor values (0-4095) to realistic units
    float coLevel = map(coValue, 0, 4095, 0, 100);  // Example: 0-100 ppm
    float no2Level = map(no2Value, 0, 4095, 0, 200); // Example: 0-200 ppb
    float airQuality = map(aqValue, 0, 4095, 0, 500); // Example AQI 0-500
    
    Serial.print("CO Level: "); Serial.print(coLevel); Serial.println(" ppm");
    Serial.print("NO2 Level: "); Serial.print(no2Level); Serial.println(" ppb");
    Serial.print("Air Quality Index: "); Serial.println(airQuality);
    
    // Update OLED Display
    display.clearDisplay();
    display.setCursor(0, 10);
    display.print("CO: "); display.print(coLevel); display.println(" ppm");
    display.print("NO2: "); display.print(no2Level); display.println(" ppb");
    display.print("AQI: "); display.println(airQuality);
    
    // Pollution alert conditions
    if (coLevel > 50 || no2Level > 100 || airQuality > 150) { // High 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
}