using System;
using System.Collections.Generic;

namespace BookExample
{
  
    public class Book
    {

        public string Title { get; private set; }
        public string Author { get; private set; }
        public decimal Price { get; private set; }

       
        public Book(string title, string author, decimal price)
        {
          
            Title = title;
            Author = author;
            Price = price;
        }

       
        public void DisplayDetails()
        {
            Console.WriteLine($"Title: {Title}");
            Console.WriteLine($"Author: {Author}");
            Console.WriteLine($"Price: ${Price:F2}");
        }
    }

   
    public class Librarian
    {
      
        private List<Book> _books;

       
        public Librarian()
        {
            _books = new List<Book>();
        }

       
        public void AddBook(Book book)
        {
            _books.Add(book);
            Console.WriteLine($"Added book: {book.Title}");
        }

       
        public void DisplayAllBooks()
        {
            if (_books.Count == 0)
            {
                Console.WriteLine("No books in the library.");
                return;
            }

            Console.WriteLine("Books in the library:");
            foreach (var book in _books)
            {
                book.DisplayDetails();
                Console.WriteLine();
            }
        }
    }
 // we should use the Dip principe here by adding interface item instead of make the librian deal with just books but its just a simple program to demonstrate the SRP 
   
    class Program
    {
        static void Main(string[] args)
        {
        
            Librarian librarian = new Librarian();

      
            Book book1 = new Book("The Great Gatsby", "F. Scott Fitzgerald", 12.99m);
            Book book2 = new Book("1984", "George Orwell", 9.99m);
            Book book3 = new Book("To Kill a Mockingbird", "Harper Lee", 10.99m);

           
            librarian.AddBook(book1);
            librarian.AddBook(book2);
            librarian.AddBook(book3);

          
            librarian.DisplayAllBooks();
        }
    }
}