namespace Exam1
{
    internal class Program
    {


        class Book
        {
            public string Title { get; set; }
            public string Author { get; set; }
            public int Year { get; set; }
            public decimal Price { get; set; }
            public int Pages { get; set; }

            public Book(string title, string author, int year, decimal price, int pages)
            {
                Title = title;
                Author = author;
                Year = year;
                Price = price;
                Pages = pages;
            }

            public override string ToString()
            {
                return $"Title: {Title}, Author: {Author}, Year: {Year}, Price: {Price:C}, Pages: {Pages}";
            }
        }

        class Library
        {
            private List<Book> books;

            public Library()
            {
                books = new List<Book>();
            }

            public void AddBook(Book book)
            {
                books.Add(book);
            }

            public void RemoveBook(string title)
            {
                books.RemoveAll(b => b.Title.Equals(title, StringComparison.OrdinalIgnoreCase));
            }

            public Book SearchByTitle(string title)
            {
                return books.Find(b => b.Title.Equals(title, StringComparison.OrdinalIgnoreCase));
            }

            public List<Book> SearchByAuthor(string author)
            {
                return books.FindAll(b => b.Author.Equals(author, StringComparison.OrdinalIgnoreCase));
            }

            public void DisplayBooks()
            {
                if (books.Count == 0)
                {
                    Console.WriteLine("No books available.");
                    return;
                }

                foreach (var book in books)
                {
                    Console.WriteLine(book);
                }
            }

            public void SaveToFile(string filename)
            {
                using (StreamWriter writer = new StreamWriter(filename))
                {
                    foreach (var book in books)
                    {
                        writer.WriteLine($"{book.Title},{book.Author},{book.Year},{book.Price},{book.Pages}");
                    }
                }
            }

            public void LoadFromFile(string filename)
            {
                if (File.Exists(filename))
                {
                    books.Clear();
                    foreach (var line in File.ReadLines(filename))
                    {
                        var parts = line.Split(',');
                        var book = new Book(parts[0], parts[1], int.Parse(parts[2]), decimal.Parse(parts[3]), int.Parse(parts[4]));
                        books.Add(book);
                    }
                }
            }
        }




        static void Main(string[] args)
        {
            Library library = new Library();
            library.LoadFromFile("books.txt");

            while (true)
            {
                Console.Clear();
                Console.WriteLine("Library Management System");
                Console.WriteLine("1. Add Book");
                Console.WriteLine("2. Remove Book");
                Console.WriteLine("3. Search Book by Title");
                Console.WriteLine("4. Search Book by Author");
                Console.WriteLine("5. Display All Books");
                Console.WriteLine("6. Save and Exit");
                Console.WriteLine("7. Exit without Saving");

                Console.Write("Choose an option: ");
                string choice = Console.ReadLine();

                switch (choice)
                {
                    case "1":
                        AddBook(library);
                        break;
                    case "2":
                        RemoveBook(library);
                        break;
                    case "3":
                        SearchBookByTitle(library);
                        break;
                    case "4":
                        SearchBookByAuthor(library);
                        break;
                    case "5":
                        library.DisplayBooks();
                        break;
                    case "6":
                        library.SaveToFile("books.txt");
                        Console.WriteLine("Books saved. Exiting...");
                        return;
                    case "7":
                        Console.WriteLine("Exiting without saving.");
                        return;
                    default:
                        Console.WriteLine("Invalid choice. Try again.");
                        break;
                }

                Console.WriteLine("Press any key to continue...");
                Console.ReadKey();
            }

            static void AddBook(Library library)
            {
                Console.Write("Enter Book Title: ");
                string title = Console.ReadLine();
                Console.Write("Enter Author: ");
                string author = Console.ReadLine();
                Console.Write("Enter Year: ");
                int year = int.Parse(Console.ReadLine());
                Console.Write("Enter Price: ");
                decimal price = decimal.Parse(Console.ReadLine());
                Console.Write("Enter Number of Pages: ");
                int pages = int.Parse(Console.ReadLine());

                library.AddBook(new Book(title, author, year, price, pages));
            }

            static void RemoveBook(Library library)
            {
                Console.Write("Enter the title of the book to remove: ");
                string title = Console.ReadLine();
                library.RemoveBook(title);
            }

            static void SearchBookByTitle(Library library)
            {
                Console.Write("Enter the title to search: ");
                string title = Console.ReadLine();
                var book = library.SearchByTitle(title);
                if (book != null)
                {
                    Console.WriteLine(book);
                }
                else
                {
                    Console.WriteLine("Book not found.");
                }
            }

            static void SearchBookByAuthor(Library library)
            {
                Console.Write("Enter the author's name to search: ");
                string author = Console.ReadLine();
                var books = library.SearchByAuthor(author);
                if (books.Count > 0)
                {
                    foreach (var book in books)
                    {
                        Console.WriteLine(book);
                    }
                }
                else
                {
                    Console.WriteLine("No books found by this author.");
                }
            }
        }



    }
}