بین الگوی مخزن و کلاس استاتیک یاور انتخاب کنید

// 1️⃣ Δημιουργία ενός interface που ορίζει τις βασικές λειτουργίες
public interface IProductRepository
{
    IEnumerable GetAll();
    Product GetById(int id);
    void Add(Product product);
    void Update(Product product);
    void Delete(int id);
}

// 2️⃣ Υλοποίηση του repository που διαχειρίζεται τη βάση δεδομένων
public class ProductRepository : IProductRepository
{
    private readonly ApplicationDbContext _context;

    public ProductRepository(ApplicationDbContext context)
    {
        _context = context;
    }

    public IEnumerable GetAll() => _context.Products.ToList();

    public Product GetById(int id) => _context.Products.Find(id);

    public void Add(Product product)
    {
        _context.Products.Add(product);
        _context.SaveChanges();
    }

    public void Update(Product product)
    {
        _context.Products.Update(product);
        _context.SaveChanges();
    }

    public void Delete(int id)
    {
        var product = _context.Products.Find(id);
        if (product != null)
        {
            _context.Products.Remove(product);
            _context.SaveChanges();
        }
    }
}

// 3️⃣ Χρήση του Repository μέσω Dependency Injection
public class ProductService
{
    private readonly IProductRepository _productRepository;

    public ProductService(IProductRepository productRepository)
    {
        _productRepository = productRepository;
    }

    public void ProcessProducts()
    {
        var products = _productRepository.GetAll();
        foreach (var product in products)
        {
            Console.WriteLine($"Product: {product.Name}");
        }
    }
}

public static class StringHelper
{
    public static string ToTitleCase(string input)
    {
        if (string.IsNullOrWhiteSpace(input))
            return string.Empty;

        return CultureInfo.CurrentCulture.TextInfo.ToTitleCase(input.ToLower());
    }

    public static bool IsValidEmail(string email)
    {
        return Regex.IsMatch(email, @"^[^@\s]+@[^@\s]+\.[^@\s]+$");
    }
}

// Χρήση της static class
string title = StringHelper.ToTitleCase("hello world"); // "Hello World"
bool isValid = StringHelper.IsValidEmail("test@email.com"); // true