using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    //Library Class///////////////////////////////////////////////////////////
    class Library
    {

        ////Potential Variables\
        Book[] library = new Book[1000];

        public Library()
        {



           // List<Book> lib = new List<Book>(library);
        }

        public void AddBook(String t, String a, int id)
        {
            if (this.searchBook(t) == -1)
            {
                Book b = new Book(a, t, id);
                library[id] = b;
            }
        }

        public int searchBook(String t)
        {
            int index = -1;
            for (int j = 0; j < library.Length; j++)
           {
                if (library[j] != null)
                {
                    if (library[j].getTitle().Equals(t))
                    {
                        index = j;
                        break;
                    }
                }
            }
            return index;
        }

        public void removeBook(String t)
        {
            if (this.searchBook(t) > -1)
            {
                library[this.searchBook(t)] = null;
            }

        }

        public String displayBook(String t)
        {
            int index = this.searchBook(t);
            return library[index].getTitle() + "'s " +
                library[index].getAuthor() + " (" +
                library[index].getId() + ")";

        }

        public String displayLibrary()
        {
            String output = "Library Contents:";

            for (int i = 0; i < library.Length; i++)
            {
                if(library[i] != null)
                {
                    output += " \n" + displayBook(library[i].getTitle());
                }


            }
            return output;

        }



        ///////////////////////Book Class/////////////////////////////

        class Book
        {
            private string title;
            private string author;
            private int id;

            public Book()
            {
                title = "Title";
                author = "Author";  //Def const.
                id = 0;
            }

            public Book(string t, string a, int i) //par. const.
            {
                title = t;
                author = a;
                id = i;
            }

            public String getTitle()
            {
                return title;
            }

            public String getAuthor()
            {
                return author;
            }

            public int getId()
            {
                return id;
            }
        }
        //////////////////////////////////Main Class//////////////////////////////////////////////////////
        class MainProject
        {
            static void Main(string[] args)
            {
                Library lib = new Library();
                lib.AddBook("C# programming", "Gesick", 4);
                lib.AddBook("java programming", "Roth", 2);
                lib.AddBook("C++ programming", "Franklin", 1);
                lib.AddBook("unity programming", "Preston", 3);
                lib.AddBook("graphics & multimedia", "Chastine", 5);
                printMenu();
                string p = Console.ReadLine();
                p = p.ToUpper();
                char pick = p[0];

                while (pick != 'Q')
                {
                    switch (pick)
                    {
                        case 'A':
                            Console.WriteLine("Input book title.");
                            string t = Console.ReadLine();
                            Console.WriteLine("Input book’s Author.");
                            string a = Console.ReadLine();

                            Console.WriteLine("Input ID number.");
                            int id = Int32.Parse(Console.ReadLine());
                            lib.AddBook(t, a, id);
                            Console.WriteLine( t + " By " + a + " has been added to the library");
                            break;

                        case 'S':
                            Console.WriteLine("Please provide the title of the book.");
                            string title = Console.ReadLine();
                            if (lib.searchBook(title) == -1)
                            {
                                Console.WriteLine("Book does not exist within the library.");
                            }
                            else
                            {
                                lib.displayBook(title);
                            }
                            break;
                        case 'D':
                           Console.WriteLine(lib.displayLibrary());
                            break;
                        case 'R':
                            Console.WriteLine("Please enter the book title that needs removal.");
                            string tit = Console.ReadLine();
                            if (lib.searchBook(tit) == -1)
                            {
                                Console.WriteLine("Book does not currently exist within the library.");
                            }
                            else
                            {
                                lib.removeBook(tit);
                                Console.WriteLine("Book successfully removed.");
                            }
                            break;
                        default:
                            Console.WriteLine("\nInvalid choice, please re-enter");
                            break;
                    }
                    printMenu();
                    p = Console.ReadLine();
                    p = p.ToUpper();
                    pick = p[0];
                }

                Console.WriteLine("good bye");

            }

            public static void printMenu()
            {
                Console.WriteLine("\nSelect one of the following:\n\n" +
                                  " A  to add a book to the library\n" +
                                  " S  to search for a book by title\n" +
                                  " D  to display the contents of the library\n" +
                                  " R  to remove a book from the library\n" +
                                  " Q  to quit this program\n\n");
                Console.Write("enter choice here: ");

            }
        }
    }
}