#define BLYNK_TEMPLATE_ID "TMPL6yg_Fum73"
#define BLYNK_TEMPLATE_NAME "Smart Occupancy and Space Utilization System"
#define BLYNK_AUTH_TOKEN "yUMqCiW43Y4Q2tBECZ7gpU0pzs6dt3GQ"

#define BLYNK_PRINT Serial

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>   // Blynk library for ESP32
#include <LiquidCrystal.h>      // LCD library for non-I2C 16x2 LCD

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

BlynkTimer timer;  // Blynk timer for periodic updates

// Pin definitions
#define PIR_PIN 12          
#define TRIG_PIN 13         
#define ECHO_PIN 14         
#define BUZZER_PIN 27        // Buzzer pin

// Non-I2C 16x2 LCD pins
#define LCD_RS 8
#define LCD_EN 9
#define LCD_D4 4
#define LCD_D5 5
#define LCD_D6 6
#define LCD_D7 7

LiquidCrystal lcd(LCD_RS, LCD_EN, LCD_D4, LCD_D5, LCD_D6, LCD_D7);  // Non-I2C 16x2 LCD

// Global variables
int pirState = LOW;        
int buzzerStatus = LOW;    
long duration;             
int distance;              

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

  // Connect to Wi-Fi and Blynk
  Serial.println("Connecting to WiFi...");
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);
  while (Blynk.connect() == false) {
    Serial.print(".");
    delay(1000);
  }
  Serial.println("Connected to Blynk");

  // Initialize sensors and actuators
  pinMode(PIR_PIN, INPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  // Initialize LCD
  lcd.begin(16, 2);  // Initialize 16x2 LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("System Ready!");
  delay(2000);
  lcd.clear();

  // Configure Blynk timer
  timer.setInterval(1000L, myTimerEvent); // Call every second
}

void myTimerEvent() {
  // PIR sensor
  pirState = digitalRead(PIR_PIN);
  String motionStatus = (pirState == HIGH) ? "Motion Detected" : "No Motion";
  
  // Debugging output to Serial Monitor
  if (pirState == HIGH) {
    Serial.println("PIR Motion Detected!");
    digitalWrite(BUZZER_PIN, HIGH);
    buzzerStatus = HIGH;
  } else {
    Serial.println("PIR No Motion");
    digitalWrite(BUZZER_PIN, LOW);
    buzzerStatus = LOW;
  }

  // Ultrasonic sensor
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;

  // Output the ultrasonic distance
  Serial.print("Ultrasonic Distance: ");
  Serial.println(distance);

  // Update LCD with information about space usage
  lcd.setCursor(0, 0);
  if (motionStatus == "Motion Detected") {
    lcd.print("LCD On: Space Busy");
    Serial.println("LCD On: Space Busy");
    lcd.setCursor(0, 1);
    lcd.print("Crowd Detected!");
    Serial.println("Crowd Detected!");
  } else {
    lcd.print("LCD On: Space Clear");
    Serial.println("LCD On: Space Clear");
    lcd.setCursor(0, 1);
    lcd.print("No Motion");
    Serial.println("No Motion");
  }

  // Display distance on the LCD (line 2)
  lcd.setCursor(0, 1);
  lcd.print("Dist: ");
  lcd.print(distance);
  lcd.print(" cm");
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Send data to Blynk with clearer motion status
  Blynk.virtualWrite(V0, motionStatus);  // Display "Motion Detected" or "No Motion"
  Blynk.virtualWrite(V1, distance);      // Send distance value
  Blynk.virtualWrite(V2, "PIR: " + motionStatus + " - Dist: " + String(distance) + "cm");  // Display both motion and distance on Blynk
  Blynk.virtualWrite(V3, buzzerStatus);  // Send buzzer state (on or off)

  // Debugging outputs for serial monitor
  Serial.print("PIR State: ");
  Serial.println(motionStatus);  // Print motion status clearly
  Serial.print("Buzzer State: ");
  Serial.println(buzzerStatus == HIGH ? "On" : "Off");
  Serial.print("Distance: ");
  Serial.println(distance);
  Serial.print("Blynk State: ");
  Serial.println(motionStatus);
}

void loop() {
  Blynk.run();  // Run Blynk
  timer.run();  // Run Blynk timer for periodic tasks
}