#define BLYNK_TEMPLATE_ID "TMPL3ln0YFxZT"
#define BLYNK_TEMPLATE_NAME "CROWD MANAGEMENT"
#define BLYNK_AUTH_TOKEN "KkmooTOwOpqcaL40luyxrTsQnjHutHiB"
#include <BlynkSimpleEsp32.h>
#include <WiFi.h>

// Wi-Fi credentials
char ssid[] = "Wokwi-GUEST";       // Your Wi-Fi SSID
char pass[] = "";                  // Your Wi-Fi password

// Blynk authentication token
char auth[] = "KkmooTOwOpqcaL40luyxrTsQnjHutHiB";   // Your Blynk auth token

// Sensor pins
#define PIR_PIN 4                  // PIR sensor pin (GPIO 4)
#define ULTRASONIC_TRIG_PIN 2      // Ultrasonic sensor TRIG pin (GPIO 2)
#define ULTRASONIC_ECHO_PIN 15     // Ultrasonic sensor ECHO pin (GPIO 15)
#define SMOKE_SENSOR_PIN 33        // Smoke or Gas sensor pin (GPIO 33)
#define PANIC_BUTTON_PIN 5         // Physical panic button pin (GPIO 5)

// Variables for sensor readings
bool motionDetected = false;        // PIR motion status
long distance = 0;                  // Ultrasonic measured distance
int crowdDensityLevel = 0;          // Crowd density level (0 = Low, 1 = Medium, 2 = High)
bool smokeDetected = false;         // Smoke or gas detection status
bool panicButtonPressed = false;    // Panic button status

void setup() {
  // Start Serial monitor
  Serial.begin(9600);
  delay(1000);

  // Debugging info
  Serial.println("Starting setup...");
  Serial.print("Connecting to Wi-Fi: ");
  Serial.println(ssid);

  // Initialize Blynk
  Blynk.begin(auth, ssid, pass);

  // Initialize sensor pins
  pinMode(PIR_PIN, INPUT);
  pinMode(ULTRASONIC_TRIG_PIN, OUTPUT);
  pinMode(ULTRASONIC_ECHO_PIN, INPUT);
  pinMode(SMOKE_SENSOR_PIN, INPUT);
  pinMode(PANIC_BUTTON_PIN, INPUT_PULLUP);
  Serial.println("Blynk connection complete");
  Serial.println("Setup complete.");
}

void loop() {
  Blynk.run();

  // Read PIR sensor
  motionDetected = digitalRead(PIR_PIN);

  // Read Ultrasonic sensor
  distance = getUltrasonicDistance();

  // Read Smoke or Gas sensor
  smokeDetected = analogRead(SMOKE_SENSOR_PIN) > 1000; // Adjust threshold as needed

  // Read Physical Panic Button
  panicButtonPressed = digitalRead(PANIC_BUTTON_PIN) == LOW;

  // Determine crowd density level
  if (motionDetected && distance < 50) {
    crowdDensityLevel = 2;  // High density
    Blynk.logEvent("high_density"); // Predefined event
  } else if (motionDetected && distance >= 50 && distance <= 100) {
    crowdDensityLevel = 1;  // Medium density
    Blynk.logEvent("moderate_density"); // Predefined event
  } else {
    crowdDensityLevel = 0;  // Low density
  }

  // Emergency alerts
  if (smokeDetected) {
    Blynk.logEvent("smoke_alert","Smoke alert !!!"); // Predefined event
    Serial.println("Smoke alert !!!");
  }

  if (panicButtonPressed) {
    Blynk.logEvent("panic_alert","Panic alert from physical button!!!"); // Predefined event
    Serial.println("Panic alert from physical button !!!");
  }

  // Send data to Blynk app
  Blynk.virtualWrite(V2, crowdDensityLevel); // Send crowd density level
  Blynk.virtualWrite(V4, distance);         // Send distance value
  Blynk.virtualWrite(V5, motionDetected);   // Send motion detection status
  Blynk.virtualWrite(V7, smokeDetected);    // Send smoke detection status
  Blynk.virtualWrite(V6, panicButtonPressed); // Send physical panic button status

  // Print data to Serial monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  Serial.print("Motion Detected: ");
  Serial.println(motionDetected ? "Yes" : "No");

  Serial.print("Crowd Density Level: ");
  if (crowdDensityLevel == 2) Serial.println("High");
  else if (crowdDensityLevel == 1) Serial.println("Medium");
  else Serial.println("Low");

  Serial.print("Smoke Detected: ");
  Serial.println(smokeDetected ? "Yes" : "No");

  Serial.print("Panic Button Pressed: ");
  Serial.println(panicButtonPressed ? "Yes" : "No");

  delay(2000); // Delay for better readings
}

// Function to calculate distance using Ultrasonic sensor
long getUltrasonicDistance() {
  long duration, distance;

  // Trigger the ultrasonic sensor
  digitalWrite(ULTRASONIC_TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(ULTRASONIC_TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(ULTRASONIC_TRIG_PIN, LOW);

  // Measure the time taken by the echo
  duration = pulseIn(ULTRASONIC_ECHO_PIN, HIGH);

  // Calculate distance in cm
  distance = duration * 0.034 / 2;
  return distance;
}

// Function to handle virtual panic button
BLYNK_WRITE(V6) {
  bool virtualPanicButton = param.asInt(); // Read virtual button state
  if (virtualPanicButton) {
    Blynk.logEvent("panic_alert","Panic alert from virtual button!!!"); // Predefined event
    Serial.println("Panic alert from virtual button !!!");
  }
}