using System.ComponentModel.DataAnnotations; using LibraryAPI.Validators; namespace LibraryAPI.Models { public class Book { public long Id { get; set; } [Required] public long AuthorId { get; set; } public Author? Author { get; set; } [Required] public int PublicationYear { get; set; } [Required] public string[]? Genres { get; set; } public int Edition { get; set; } [Required] [ISBN(13)] public string? ISBN { get; set; } [Required] [StringLength(128, ErrorMessage = "Title too long")] public string? Title { get; set; } } }