#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <SPI.h>
#include <MFRC522.h>

// LCD setup (I2C address usually 0x27 or 0x3F)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// RFID setup
#define SS_PIN 7
#define RST_PIN 10
MFRC522 rfid(SS_PIN, RST_PIN);

// Button pins
#define MANUAL_UNLOCK_BUTTON 2
#define LOCK_BUTTON1 3
#define LOCK_BUTTON2 4

// LED pins
#define RED_LED 13
#define GREEN_LED 5

// Relay pin
#define RELAY 6

// Variables
bool doorLocked = true;
String authorizedCard = "01020304"; // Replace with your card's UID

void setup() {
  Serial.begin(9600);
  
  // Initialize pins
  pinMode(RED_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
  pinMode(RELAY, OUTPUT);
  pinMode(MANUAL_UNLOCK_BUTTON, INPUT_PULLUP);
  pinMode(LOCK_BUTTON1, INPUT_PULLUP);
  pinMode(LOCK_BUTTON2, INPUT_PULLUP);
  
  // Initialize LCD
  lcd.init();
  lcd.backlight();
  
  // Initialize RFID
  SPI.begin();
  rfid.PCD_Init();
  
  // Display startup messages
  displayStartupMessage();
  
  // Set initial door state
  lockDoor();
}

void loop() {
  // Check RFID card
  if (rfid.PICC_IsNewCardPresent() && rfid.PICC_ReadCardSerial()) {
    String cardUID = getCardUID();
    
    if (cardUID == authorizedCard) {
      if (doorLocked) {
        unlockDoor();
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Door Opened");
        lcd.setCursor(0, 1);
        lcd.print("Welcome!");
      } else {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Door is already");
        lcd.setCursor(0, 1);
        lcd.print("opened");
        delay(2000);
        displayDoorStatus();
      }
    } else {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Access Denied");
      lcd.setCursor(0, 1);
      lcd.print("Invalid Card");
      delay(2000);
      displayDoorStatus();
    }
    
    rfid.PICC_HaltA();
  }
  
  // Check manual unlock button (pin 2)
  if (digitalRead(MANUAL_UNLOCK_BUTTON) == LOW) {
    delay(50); // Debounce
    while(digitalRead(MANUAL_UNLOCK_BUTTON) == LOW);
    
    if (doorLocked) {
      unlockDoor();
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Door Opened");
      lcd.setCursor(0, 1);
      lcd.print("Manually");
    } else {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Door is already");
      lcd.setCursor(0, 1);
      lcd.print("opened");
    }
    delay(2000);
    displayDoorStatus();
  }
  
  // Check lock button 1 (pin 3)
  if (digitalRead(LOCK_BUTTON1) == LOW) {
    delay(50); // Debounce
    while(digitalRead(LOCK_BUTTON1) == LOW);
    
    if (!doorLocked) {
      lockDoor();
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Door Closed");
    } else {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Door already");
      lcd.setCursor(0, 1);
      lcd.print("closed");
    }
    delay(2000);
    displayDoorStatus();
  }
  
  // Check lock button 2 (pin 4)
  if (digitalRead(LOCK_BUTTON2) == LOW) {
    delay(50); // Debounce
    while(digitalRead(LOCK_BUTTON2) == LOW);
    
    if (!doorLocked) {
      lockDoor();
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Door Closed");
    } else {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Door already");
      lcd.setCursor(0, 1);
      lcd.print("closed");
    }
    delay(2000);
    displayDoorStatus();
  }
}

void displayStartupMessage() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Smart Door");
  lcd.setCursor(0, 1);
  lcd.print("System");
  delay(2000);
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Mohammed Saleh");
  lcd.setCursor(0, 1);
  lcd.print("Yahyawi High");
  delay(2000);
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("School");
  delay(1500);
  
  displayDoorStatus();
}

void displayDoorStatus() {
  lcd.clear();
  if (doorLocked) {
    lcd.setCursor(0, 0);
    lcd.print("Door Locked");
  } else {
    lcd.setCursor(0, 0);
    lcd.print("Door Unlocked");
  }
}

void unlockDoor() {
  doorLocked = false;
  digitalWrite(RED_LED, LOW);
  digitalWrite(GREEN_LED, HIGH);
  digitalWrite(RELAY, HIGH); // Activate relay to unlock
}

void lockDoor() {
  doorLocked = true;
  digitalWrite(RED_LED, HIGH);
  digitalWrite(GREEN_LED, LOW);
  digitalWrite(RELAY, LOW); // Deactivate relay to lock
}

String getCardUID() {
  String uid = "";
  for (byte i = 0; i < rfid.uid.size; i++) {
    uid += String(rfid.uid.uidByte[i] < 0x10 ? "0" : "");
    uid += String(rfid.uid.uidByte[i], HEX);
  }
  uid.toUpperCase();
  return uid;
}