MainPage.xaml.cs

namespace LibraryOne;
using LibraryOne.DataBase;
using LibraryOne.BookClass;
using LibraryOne.UserClass;
using MySqlConnector;
using System.Collections.ObjectModel;
using System.Threading.Tasks;
using System;
using System.Globalization;



public partial class MainPage : ContentPage
{
	// sets the Database property to class type Sqldatabase
	public SqlDatabase Database { get; set; }

	//Lists
	List<Children> ChildrenBooks = new();

	List<Mystery> MysteryBooks = new();

	List<Romance> RomanceBooks = new();

	List<Science> ScienceBooks = new();

	List<Customer> Customers = new();

	List<Librarian> Librarians = new();

	List<Book> Allbooks = new();

	// picker for found books
	ObservableCollection<Book> Foundbooks = new ObservableCollection<Book>();

	// Added for picker function in checkout page
	private Book selectedBook;

	public Book SelectedBook
	{
		get { return selectedBook; }
		set
		{
			selectedBook = value;
			OnPropertyChanged();
		}
	}


	public MainPage()
	{
		InitializeComponent();

		BindingContext = this;

		// inialize and create sqldatabase object/class
		Database = new SqlDatabase();


		// calls open method in sqldatabase class 
		Database.Open();


		// calls methods in sql data base class and stores values into the lists
		Customers = Database.LoadCustomers();

		Librarians = Database.LoadLibrarians();


		ChildrenBooks = Database.LoadChildrenBooks();
		Allbooks.AddRange(ChildrenBooks);


		MysteryBooks = Database.LoadMysteryBooks();
		Allbooks.AddRange(MysteryBooks);


		RomanceBooks = Database.LoadRomanceBooks();
		Allbooks.AddRange(RomanceBooks);


		ScienceBooks = Database.LoadScienceBooks();
		Allbooks.AddRange(ScienceBooks);

		// found book picker item source = observable collection
		BookPicker.ItemsSource = Foundbooks;




	}


	// Picker selected index to find book selected
	private void Picker_SelectedIndexChanged(object sender, EventArgs e)
	{
		Picker picker = (Picker)sender;
		int selectedIndex = picker.SelectedIndex;

		if (selectedIndex >= 0 && selectedIndex < Foundbooks.Count)
		{
			SelectedBook = Foundbooks[selectedIndex];
		}
	}

	// Go to checkout page
	private async void GoToCheckoutPage(object sender, EventArgs e)
	{
		if (selectedBook == null)
		{
			DisplayAlert("Ooops", "Please make sure to select a book to checkout", "OK");
		}
		else
		{
			await Navigation.PushAsync(new CheckoutPage(SelectedBook));
		}
	}


	// on search button clicked calls search method 
	public void Button_ClickedSearch(System.Object sender, System.EventArgs e)
	{
		// clears found book collection so picker is cleared each press
		Foundbooks.Clear();

		// calls search method 
		SearchBook();

	}

	// Search for book 
	public async void SearchBook()
	{
		// sets input feild text as varible and call capitalize frist letter of each word method
		string BookTitleSearch = CapitalizeFirstLetter(SearchTitle.Text);


		string BookAuthorFNSearch = CapitalizeFirstLetter(SearchAuthorFirstName.Text);



		string BookAuthorLNSearch = CapitalizeFirstLetter(SearchAuthorLastName.Text);

    // Go to checkout page
    private async void GoToCheckoutPage(object sender, EventArgs e)
    {
        if (SelectedBook == null)
        {
            await DisplayAlert("Ooops", "Please make sure to select a book to checkout", "OK");
        }
        else
        {
            await Navigation.PushAsync(new CheckoutPage(SelectedBook));
        }
    }



		try // exceptions for is search is null or if author first & last name are not filled out 
		{

			if (string.IsNullOrEmpty(BookTitleSearch) & string.IsNullOrEmpty(BookAuthorFNSearch) & string.IsNullOrEmpty(BookAuthorLNSearch))
			{
				throw new InvalidDataException();
			}
			else if (!string.IsNullOrEmpty(BookTitleSearch) & !string.IsNullOrEmpty(BookAuthorFNSearch) & string.IsNullOrEmpty(BookAuthorLNSearch))
			{
				throw new ArgumentException();
			}
			else if (!string.IsNullOrEmpty(BookTitleSearch) & string.IsNullOrEmpty(BookAuthorFNSearch) & !string.IsNullOrEmpty(BookAuthorLNSearch))
			{
				throw new ArgumentException();
			}
			else if (string.IsNullOrEmpty(BookTitleSearch) & !string.IsNullOrEmpty(BookAuthorFNSearch) & string.IsNullOrEmpty(BookAuthorLNSearch))
			{
				throw new ArgumentException();
			}
			else if (string.IsNullOrEmpty(BookTitleSearch) & string.IsNullOrEmpty(BookAuthorFNSearch) & !string.IsNullOrEmpty(BookAuthorLNSearch))
			{
				throw new ArgumentException();
			}



		}
		catch (InvalidDataException)
		{

			await DisplayAlert("Alert", "Search fields cannot be empty", "OK");

		}
		catch (ArgumentException)
		{
			await DisplayAlert("Alert", "Must enter author first & last name", "OK");
		}


		// look for a match in the books list after input is filled out 
		// exception will throw error if no match is found
		int bookCounter = 0;
		try
		{

			if (!string.IsNullOrEmpty(BookTitleSearch) || (!string.IsNullOrEmpty(BookAuthorFNSearch) & !string.IsNullOrEmpty(BookAuthorLNSearch)))
			{

				foreach (Book book in Allbooks)
				{
					if (BookTitleSearch == book.Title || (BookAuthorFNSearch == book.AuthorFirstName & BookAuthorLNSearch == book.AuthorLastName))
					{


						//string DisplayBook = $"ISBN: {book.Isbn}, Title: {book.Title}, Author: {book.AuthorFirstName} {book.AuthorLastName}";

						Foundbooks.Add(book);
						bookCounter++;

					}

				}

				if (bookCounter == 0)
				{
					throw new ArgumentException();
				}

				BookPicker.SelectedIndex = 0;
			}


		}
		catch (ArgumentException)
		{
			await DisplayAlert("Alert", "Could not find that book or author", "Search Again");
		}


	}




	// Capitalizes first letter of each word for easier input and interaction with database values
	static string CapitalizeFirstLetter(string input)
	{
		if (string.IsNullOrEmpty(input)) // couldnt get exceptions to work without this if 
		{
			return string.Empty;
		}

		TextInfo textInfo = CultureInfo.CurrentCulture.TextInfo;

		return textInfo.ToTitleCase(input);
	}






}