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

// Constants
#define PIR_PIN_IN 34
#define PIR_PIN_OUT 35
#define LED_PIN 25      // Changed to avoid conflict
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
#define Fan_PIN 12
#define Temp_PIN 4
#define MQ2_PIN 16
#define BUZZER_PIN 26   // New buzzer pin

//// Constants-with websocket real time monitoring
// #define PIR_PIN_IN 34
// #define PIR_PIN_OUT 35
// #define LED_PIN 27
// #define SCREEN_WIDTH 128
// #define SCREEN_HEIGHT 64
// #define OLED_RESET -1
// #define Fan_PIN 25
// #define DHTPIN 4       // Changed from Temp_PIN to DHTPIN
// #define MQ2_PIN 16
// #define BUZZER_PIN 26
// #define DHTTYPE DHT22

// OLED Display Object
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// People Counter Class
class PeopleCounter {
private:
    int peopleCount;
    bool motionDetected_IN;
    bool motionDetected_OUT;
    unsigned long lastEventTime;
    String lastEventType;
    int lastPersonID;
    bool eventChanged;

public:
    PeopleCounter() {
        peopleCount = 0;
        motionDetected_IN = false;
        motionDetected_OUT = false;
        lastEventTime = 0;
        lastEventType = "";
        lastPersonID = 0;
        eventChanged = false;
    }

    void testHardwarePin() {
        pinMode(Temp_PIN, INPUT);
        pinMode(Fan_PIN, OUTPUT);
        pinMode(MQ2_PIN, INPUT_PULLUP);
        pinMode(BUZZER_PIN, OUTPUT);
        digitalWrite(Fan_PIN, LOW);
        digitalWrite(BUZZER_PIN, LOW);
        
        int temp = digitalRead(Temp_PIN);
        int MQ = digitalRead(MQ2_PIN);
        
        if (temp == LOW && MQ == LOW) {
            Serial.println("Temp MQ");
        }
    }

    void initializeSystem() {
        pinMode(PIR_PIN_IN, INPUT_PULLUP);
        pinMode(PIR_PIN_OUT, INPUT_PULLUP);
        pinMode(LED_PIN, OUTPUT);
        digitalWrite(LED_PIN, LOW);
        Serial.begin(115200);

        if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
            Serial.println(F("SSD1306 allocation failed"));
            while (true);
        }

        display.clearDisplay();
        display.setTextSize(1);
        display.setTextColor(WHITE);
        display.setCursor(5, 5);
        display.println("Initializing...");
        display.display();
        delay(1000);
        display.clearDisplay();
    }

    void detectMotion() {
        int val_IN = digitalRead(PIR_PIN_IN);
        int val_OUT = digitalRead(PIR_PIN_OUT);

        if (val_IN == LOW && !motionDetected_IN) {
            motionDetected_IN = true;
            peopleCount++;
            lastPersonID++;
            lastEventTime = millis();
            lastEventType = "IN";
            eventChanged = true;
            Serial.println("Person Entered");
        } else if (val_IN == HIGH && motionDetected_IN) {
            motionDetected_IN = false;
        }

        if (val_OUT == LOW && !motionDetected_OUT) {
            motionDetected_OUT = true;
            if (peopleCount > 0) {
                peopleCount--;
                lastEventTime = millis();
                lastEventType = "OUT";
                eventChanged = true;
                Serial.println("Person Exited");
            }
        } else if (val_OUT == HIGH && motionDetected_OUT) {
            motionDetected_OUT = false;
        }
    }

    void controlLED() {
        digitalWrite(LED_PIN, peopleCount > 0 ? HIGH : LOW);
    }

    void updateOLED() {
        if (eventChanged) {
            displayTimeAndCount();
            eventChanged = false;
        }
    }

    void monitorEnvironment() {
        int tempValue = analogRead(Temp_PIN); // Read analog temperature sensor
        float voltage = tempValue * (3.3 / 4095.0); // For ESP32 12-bit ADC and 3.3V
        float temperatureC = (voltage - 0.5)*100;  // TMP36 correction

        int mq2Status = digitalRead(MQ2_PIN);

        Serial.print("Temperature: ");
        Serial.println(temperatureC);

        Serial.print("Gas Sensor: ");
        Serial.println(mq2Status == LOW ? "Gas Detected!" : "No Gas");

        // Fan and Buzzer control
        if (temperatureC > 24 && peopleCount > 0) {
            digitalWrite(Fan_PIN, HIGH);
            digitalWrite(BUZZER_PIN, HIGH);
            Serial.println("Fan and Buzzer ON");
        } else {
            digitalWrite(Fan_PIN, LOW);
            digitalWrite(BUZZER_PIN, LOW);
            Serial.println("Fan and Buzzer OFF");
        }

        // Display gas alert on OLED
        if (mq2Status == LOW) { // Gas detected
            display.clearDisplay();
            display.setTextSize(1);
            display.setCursor(0, 0);
            display.println("Warning!");
            display.println("Gas Detected");
            display.display();
            
        }
    }

private:
    void displayTimeAndCount() {
        unsigned long seconds = (lastEventTime / 1000) % 60;
        unsigned long minutes = (lastEventTime / 60000) % 60;
        unsigned long hours = (lastEventTime / 3600000) % 24;

        display.clearDisplay();
        display.setTextSize(1);
        display.setCursor(1, 1);
        display.print("Event: ");
        display.print(lastEventType);
        display.setCursor(0, 15);
        display.print("Time: ");
        if (hours < 10) display.print("0");
        display.print(hours);
        display.print(":");
        if (minutes < 10) display.print("0");
        display.print(minutes);
        display.print(":");
        if (seconds < 10) display.print("0");
        display.print(seconds);
        display.setCursor(0, 35);
        display.print("Count: ");
        display.print(peopleCount);
        display.display();
    }

} counter;


void setup() {
    counter.initializeSystem();
    counter.testHardwarePin();
}

void loop() {
    counter.detectMotion();
    counter.controlLED();
    counter.updateOLED();
    counter.monitorEnvironment();
    delay(1000);
}