#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <MPU6050.h>

#define BUZZER_PIN 26
#define POT_PIN 34 // ADC pin to simulate heart rate

Adafruit_SSD1306 display(128, 64, &Wire, -1);
MPU6050 mpu;

void setup() {
  Serial.begin(115200);
  pinMode(BUZZER_PIN, OUTPUT);
  Wire.begin();
  mpu.initialize();

  if (!mpu.testConnection()) {
    Serial.println("MPU6050 connection failed!");
    while (1);
  }

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED init failed");
    while (1);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
}

void loop() {
  int heartRateSim = analogRead(POT_PIN) / 40; // Simulated HR 0-1023 → 0-25
  int16_t ax, ay, az;
  mpu.getAcceleration(&ax, &ay, &az);

  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("Sim HR: ");
  display.println(heartRateSim);
  display.print("AY: ");
  display.println(ay);
  display.display();

  bool fatigueDetected = false;

  if (heartRateSim < 10) { // Simulated low HR threshold
    fatigueDetected = true;
    Serial.println("Low heart rate detected!");
  }

  if (abs(ay) > 15000) { // Simulate nodding detection
    fatigueDetected = true;
    Serial.println("Drowsy head movement detected!");
  }

  if (fatigueDetected) {
    digitalWrite(BUZZER_PIN, HIGH);
    delay(500);
    digitalWrite(BUZZER_PIN, LOW);
  }

  delay(500);
}