#include <Wire.h>
#include <MPU6050.h>
#include <SoftwareSerial.h>  // For GPS

// Pins
const int buttonPin = A2;    // Panic button
const int ledPin = 5;        // LED (vibration substitute)
const int hrPotPin = A1;     // Potentiometer for heart rate simulation

// GPS Setup
SoftwareSerial gpsSerial(3, 4); // RX, TX (connect to GPS TX/RX)

// IMU
MPU6050 mpu;

void setup() {
  Serial.begin(9600);
  Wire.begin();
  
  // Initialize components
  mpu.initialize();
  gpsSerial.begin(9600);  // GPS baud rate
  
  // Configure pins
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(ledPin, OUTPUT);
  pinMode(hrPotPin, INPUT);
}

void loop() {
  // 1. Read sensors
  int16_t ax, ay, az;
  mpu.getAcceleration(&ax, &ay, &az);
  bool buttonPressed = (digitalRead(buttonPin) == LOW);
  int heartRate = map(analogRead(hrPotPin), 0, 1023, 40, 180);

  // 2. Detect anomalies
  if (abs(ax) > 15000 || abs(ay) > 15000) {
    triggerAlert("MOTION ALERT!");
  }
  if (buttonPressed) {
    triggerAlert("PANIC BUTTON PRESSED!");
  }
  if (heartRate > 120) {
    triggerAlert("HIGH HEART RATE: " + String(heartRate) + " BPM!");
  }

  // 3. Check GPS (non-blocking)
  if (gpsSerial.available()) {
    String gpsData = gpsSerial.readStringUntil('\n');
    if (gpsData.startsWith("$GPRMC")) {
      Serial.println("GPS: " + gpsData);
    }
  }

  delay(100);
}

void triggerAlert(String msg) {
  Serial.println(msg);
  
  // GPS fix
  if (gpsSerial.available()) {
    String gpsData = gpsSerial.readStringUntil('\n');
    if (gpsData.startsWith("$GPRMC")) {
      Serial.println("LOCATION: " + gpsData);
    }
  } else {
    Serial.println("LOCATION: 37.7749°N, 122.4194°W"); // Fallback mock
  }

  // Vibration/LED Feedback
  for (int i = 0; i < 3; i++) {
    digitalWrite(ledPin, HIGH);
    delay(300);
    digitalWrite(ledPin, LOW);
    delay(300);
  }
}