#define BLYNK_PRINT Serial

#define BLYNK_TEMPLATE_ID "TMPL5QMsFljS3"
#define BLYNK_TEMPLATE_NAME "SMART DOOR LOCKED SYSTEM"
#define BLYNK_AUTH_TOKEN "I4KHcmyxxydvql7ZzBC__WfYGrB549SP"

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <ESP32Servo.h>
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>

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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

Servo servo;

const int pirPin = 27;
const int buzzerPin = 2;
const int redLEDPin = 16;
const int greenLEDPin = 17;
const int trigPin = 26;
const int echoPin = 25;
const int servoPin = 18;
const int buttonPin = 14;

const int lockPosition = 0;  
const int unlockPosition = 90;  

int buttonState = 0;
int lastButtonState = 0;
bool isLocked = false;

unsigned long duration;
float distance;

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

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("Unable to connect"));
    for (;;);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Smart Door Lock System");
  display.display();

  servo.attach(servoPin);

  pinMode(pirPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(redLEDPin, OUTPUT);
  pinMode(greenLEDPin, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buttonPin, INPUT_PULLUP);
  
  servo.write(lockPosition);
  isLocked = true;

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

void loop() {
  Blynk.run();
  readSensor();

  // PIR sensor
  int pirState = digitalRead(pirPin);
  if (pirState == HIGH) {
    Serial.println("Motion detected, Buzzer ON!");
    digitalWrite(buzzerPin, HIGH);
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("Motion detected, Buzzer ON!");
    display.display();
  } else {
    Serial.println("No motion detected, Buzzer OFF");
    digitalWrite(buzzerPin, LOW);
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("No motion detected, Buzzer OFF");
    display.display();
  }

  // Servo Motor
  buttonState = digitalRead(buttonPin);

  if (buttonState != lastButtonState) {
    if (buttonState == LOW) {  
      isLocked = !isLocked;  

      if (isLocked) {
        servo.write(lockPosition);
        Serial.println("Door Locked");
      } else {
        servo.write(unlockPosition);
        Serial.println("Door Unlocked");
      }
    }
    delay(50);
  }
  lastButtonState = buttonState;
}

long pre = 0;
void readSensor(){
  if(millis() - pre > 2000){
    pre = millis();
    digitalWrite(trigPin, LOW);
    delay(10);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);  
    digitalWrite(trigPin, LOW);
    duration = pulseIn(echoPin, HIGH);
    distance = (duration / 2.0) / 29.0;
    
    Blynk.virtualWrite(V5, distance); // Send distance to Blynk app
    
    if(distance < 100){
      Blynk.virtualWrite(V1, HIGH); // Turn on green LED widget
      Blynk.virtualWrite(V2, LOW); // Turn off red LED widget
      digitalWrite(greenLEDPin, HIGH);
      digitalWrite(redLEDPin, LOW);
    } else {
      Blynk.virtualWrite(V1, LOW); // Turn off green LED widget
      Blynk.virtualWrite(V2, HIGH); // Turn on red LED widget
      digitalWrite(greenLEDPin, LOW);
      digitalWrite(redLEDPin, HIGH);
    }
    
    Serial.println(distance);
  }
}

// Blynk virtual pin write handlers
BLYNK_WRITE(V1) {
  int pinValue = param.asInt();
  digitalWrite(greenLEDPin, pinValue);
}

BLYNK_WRITE(V2) {
  int pinValue = param.asInt();
  digitalWrite(redLEDPin, pinValue);
}