LibraryApp/LibraryApp.Domain/Entities/Book.cs

namespace LibraryApp.Domain.Entities;

public class Book
{
    public BookId Id { get; private set; }
    public BookTitle Title { get; private set; }
    public BookAuthor Author { get; private set; }

    public Book(BookTitle title, BookAuthor author) 
        : this(new BookId(string.Empty), title, author)
    { }

    public Book(BookId id, BookTitle title, BookAuthor author)
    {
        Id = id;
        Title = title;
        Author = author;
    }

    public Book UpdateTitle(string newTitle)
    {
        Title = new (newTitle);
        return this;
    }
    public Book UpdateAuthor(string newAuthor)
    {
        Author = new (newAuthor);
        return this;
    }
}

public record BookId : DbId
{
    public BookId(string id) : base(id) {}
}

public record BookTitle
{
    public string Title { get; init; }

    public BookTitle(string title)
    {
        if(string.IsNullOrWhiteSpace(title))
        {
            throw new ArgumentException("Title cannot be empty.");
        }
        Title = title;
    }
}

public record BookAuthor
{
    public string Author { get; init; }

    public BookAuthor(string author)
    {
        if(string.IsNullOrWhiteSpace(author))
        {
            throw new ArgumentException("Author cannot be empty.");
        }
        Author = author;
    }
}