#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>

// --- Pin Definitions ---
#define I2C_SDA         21
#define I2C_SCL         22
#define ONEWIRE_BUS     4   // DS18B20 Data Pin
#define POT_PIN         34  // Potentiometer (for simulated GSR/Stress)
#define LED_PIN         13  // LED (for simulated haptic motor)

// --- Global Objects ---
Adafruit_SSD1306 display(128, 64, &Wire, -1);
OneWire oneWire(ONEWIRE_BUS);
DallasTemperature sensors(&oneWire);
Adafruit_MPU6050 mpu;

// --- Global Variables ---
float temperatureC = 0.0;
int gsrValue = 0;

void setup() {
  Serial.begin(115200);

  // Setup I2C
  Wire.begin(I2C_SDA, I2C_SCL);

  // 1. Setup OLED Display
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("System Booting...");
  display.display();
  delay(1000);

  // 2. Setup Temperature Sensor (DS18B20)
  sensors.begin();

  // 3. Setup Motion Sensor (MPU-6050)
  if (!mpu.begin()) {
    Serial.println("Failed to find MPU6050 chip");
    display.println("MPU-6050 NOT FOUND");
    display.display();
    while (1);
  }
  Serial.println("MPU6050 Found!");

  // 4. Setup LED
  pinMode(LED_PIN, OUTPUT);
  
  // 5. Setup Potentiometer (Analog Input)
  pinMode(POT_PIN, INPUT);
}

void loop() {
  // --- 1. READ REAL SENSORS ---

  // Read Temperature
  sensors.requestTemperatures(); 
  temperatureC = sensors.getTempCByIndex(0);

  // Read "Stress" from Potentiometer
  // Reads 0-4095, map to 0-100%
  gsrValue = map(analogRead(POT_PIN), 0, 4095, 0, 100);

  // Read Motion
  sensors_event_t a, g, temp;
  mpu.getEvent(&a, &g, &temp);
  float accelX = a.acceleration.x;


  // --- 2. GENERATE SIMULATED DATA (FOR WOKWI) ---

  // Simulate Heart Rate (65-90 bpm)
  int heartRate = random(65, 90);

  // Simulate Blood Pressure (110-125 / 70-85)
  int bpSystolic = random(110, 125);
  int bpDiastolic = random(70, 85);

  // Simulate GPS Location (Bonus)
  float latitude = 12.3456 + (random(-10, 10) / 10000.0);
  float longitude = 78.9101 + (random(-10, 10) / 10000.0);

  
  // --- 3. DISPLAY ALL DATA ---
  display.clearDisplay();
  display.setCursor(0, 0);
  display.setTextSize(1);

  // --- Page 1: Vitals ---
  display.printf("HR: %d bpm (SIM)\n", heartRate);
  
  display.printf("BP: %d/%d (SIM)\n", bpSystolic, bpDiastolic);
  
  display.printf("Temp: %.1f C\n", temperatureC);

  display.printf("Stress: %d%%\n", gsrValue);

  display.printf("Acc.X: %.1f\n", accelX);

  // --- Page 2: Location (Bonus) ---
  display.setCursor(0, 50);
  display.printf("Lat: %.4f\n", latitude);
  display.printf("Lon: %.4f\n", longitude);

  display.display();


  // --- 4. Haptic Alert Logic ---
  // If "stress" is over 90%, turn on the LED
  if (gsrValue > 90) {
    digitalWrite(LED_PIN, HIGH);
  } else {
    digitalWrite(LED_PIN, LOW);
  }

  delay(1000); // Update every second
}