#define BLYNK_PRINT Serial

#define BLYNK_TEMPLATE_ID "TMPL5A5IKGiWu"
#define BLYNK_TEMPLATE_NAME "IOT Based Health Monitoring System Using ESP32"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <DHT.h>
#include <LiquidCrystal_I2C.h>

char auth[] = "dPwaOMahpx1KvmMqtQQOg15ZGHRzQDhd";
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// DHT22
#define DHTPIN 4
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// LDR simulates heart rate
const int ldrPin = 34;

// Fall button
const int fallPin = 0;

// LCD
LiquidCrystal_I2C lcd(0x27, 16, 2);

float tempC;
int heartRate;
int spo2;
bool fallDetected;

// thresholds
float TEMP_HIGH = 37.5;
int HR_LOW = 60;
int HR_HIGH = 100;
int SPO2_LOW = 92;

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

  pinMode(fallPin, INPUT_PULLUP);

  dht.begin();
  lcd.init();
  lcd.backlight();

  Blynk.begin(auth, ssid, pass);
}

void loop() {
  Blynk.run();

  // Read temperature
  tempC = dht.readTemperature();
  if (isnan(tempC)) tempC = 36.5;

  // LDR → heart rate simulation
  int lightLevel = analogRead(ldrPin);
  heartRate = map(lightLevel, 0, 4095, 60, 110);

  // SpO2 simulation
  spo2 = random(90, 100);

  // Fall detection
  fallDetected = (digitalRead(fallPin) == LOW);

  Serial.print("Temp: "); Serial.print(tempC);
  Serial.print("  HR: "); Serial.print(heartRate);
  Serial.print("  SpO2: "); Serial.print(spo2);
  Serial.print("  FALL: "); Serial.println(fallDetected);

  // Send to Blynk
  Blynk.virtualWrite(V1, tempC);
  Blynk.virtualWrite(V2, heartRate);
  Blynk.virtualWrite(V3, spo2);
  Blynk.virtualWrite(V4, fallDetected ? 1 : 0);

  // LCD Display
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(tempC);
  lcd.print(" H:");
  lcd.print(heartRate);

  lcd.setCursor(0, 1);
  lcd.print("O2:");
  lcd.print(spo2);
  lcd.print("% F:");
  lcd.print(fallDetected ? "YES" : "NO ");

  // Alert conditions
  if (tempC > TEMP_HIGH || heartRate < HR_LOW || heartRate > HR_HIGH ||
      spo2 < SPO2_LOW || fallDetected) 
  {
    Blynk.logEvent("alert", "⚠️ Patient abnormal vitals or FALL detected!");
  }

  delay(1500);
}