#include <SPI.h>
#include <MFRC522.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <EEPROM.h>
#include "RTClib.h"

// RFID
#define SS_PIN 21
#define RST_PIN 22
MFRC522 mfrc522(SS_PIN, RST_PIN);

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

// LED
#define LED_PIN 5

// RTC
RTC_DS3231 rtc;

// إعداد EEPROM
#define MAX_STUDENTS 20        // أقصى عدد طلاب
#define EEPROM_START 0         // بداية تخزين البيانات في EEPROM
#define NAME_LENGTH 16         // طول اسم الطالب
#define UID_LENGTH 8           // طول UID (HEX) بدون مسافات

struct Student {
  char uid[UID_LENGTH+1];
  char name[NAME_LENGTH+1];
};

Student students[MAX_STUDENTS];

void setup() {
  Serial.begin(115200);
  SPI.begin();
  mfrc522.PCD_Init();

  Wire.begin(16,17); // SDA=16, SCL=17
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("Scan your card...");

  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);

  // بدء RTC
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  // تحميل بيانات الطلاب من EEPROM
  loadStudentsFromEEPROM();

  Serial.println("System Ready.");
}

void loop() {
  if (!mfrc522.PICC_IsNewCardPresent()) return;
  if (!mfrc522.PICC_ReadCardSerial()) return;

  String uidStr = "";
  for (byte i = 0; i < mfrc522.uid.size; i++) {
    if (mfrc522.uid.uidByte[i] < 0x10) uidStr += "0";
    uidStr += String(mfrc522.uid.uidByte[i], HEX);
  }
  uidStr.toUpperCase();

  String studentName = "Unknown";
  for (int i=0; i<MAX_STUDENTS; i++) {
    if (uidStr.equals(String(students[i].uid))) {
      studentName = String(students[i].name);
      break;
    }
  }

  // الحصول على الوقت والتاريخ من RTC
  DateTime now = rtc.now();
  char buffer[30];
  sprintf(buffer, "%02d/%02d/%04d %02d:%02d:%02d",
          now.day(), now.month(), now.year(),
          now.hour(), now.minute(), now.second());

  // طباعة سجل في Serial Monitor
  Serial.print(buffer);
  Serial.print(" - ");
  Serial.println(studentName);

  // عرض الاسم على LCD
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Student:");
  lcd.setCursor(0,1);
  lcd.print(studentName);

  if (studentName != "Unknown") digitalWrite(LED_PIN, HIGH);
  else digitalWrite(LED_PIN, LOW);

  delay(3000);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Scan your card...");
  digitalWrite(LED_PIN, LOW);

  mfrc522.PICC_HaltA();
}

// === وظائف EEPROM ===
void loadStudentsFromEEPROM() {
  for (int i=0; i<MAX_STUDENTS; i++) {
    int addr = EEPROM_START + i*(UID_LENGTH+NAME_LENGTH);
    for (int j=0; j<UID_LENGTH; j++) students[i].uid[j] = EEPROM.read(addr+j);
    students[i].uid[UID_LENGTH] = '\0';
    for (int j=0; j<NAME_LENGTH; j++) students[i].name[j] = EEPROM.read(addr+UID_LENGTH+j);
    students[i].name[NAME_LENGTH] = '\0';
  }
}

void saveStudentToEEPROM(int index, String uid, String name) {
  if (index<0 || index>=MAX_STUDENTS) return;
  int addr = EEPROM_START + index*(UID_LENGTH+NAME_LENGTH);
  for (int i=0; i<UID_LENGTH; i++) EEPROM.write(addr+i, i<uid.length()? uid[i] : 0);
  for (int i=0; i<NAME_LENGTH; i++) EEPROM.write(addr+UID_LENGTH+i, i<name.length()? name[i] : 0);
  EEPROM.commit();
  loadStudentsFromEEPROM();
}