BorrowBook

namespace MyLibrary.App.Pages.Books
{
    using Data;
    using MyLibrary.Models;
    using Microsoft.AspNetCore.Mvc;
    using Microsoft.AspNetCore.Mvc.RazorPages;
    using Microsoft.AspNetCore.Mvc.Rendering;
    using System;
    using System.Threading.Tasks;

    public class BorrowModel : PageModel

    {
        private readonly MyLibraryDbContext context;

        public BorrowModel(MyLibraryDbContext context)
        {
            this.context = context;
        }

        [BindProperty]
        public int Id { get; set; }

        [BindProperty]
        public int BorrowerId { get; set; }

        [BindProperty]
        public DateTime BorrowDate { get; set; }

        [BindProperty]
        public DateTime ReturnDate { get; set; }


        public BookBorrower BookBorrower { get; set; }

        public IActionResult OnGet(int id)
        {
            InitializeBorrowers();
            return Page();
        }


        public async Task<IActionResult> OnPostAsync()
        {
            this.BookBorrower = new BookBorrower()
            {
                BookId = this.Id,
                BorrowerId = this.BorrowerId,
                BorrowDate = this.BorrowDate,
                ReturnDate = this.ReturnDate
            };

            if (!this.ModelState.IsValid)
            {
                InitializeBorrowers();
                return Page();
            }

            try
            {
                this.context.BookBorrowers.Add(this.BookBorrower);
                await this.context.SaveChangesAsync();

                var book = this.context.Books.Find(Id);
                book.IsBorrowed = true;
                await this.context.SaveChangesAsync();

                this.TempData["Success"] = $@"You land book ""{this.BookBorrower.Book.Title}"" to a frend!";

            }
            catch (Exception e)
            {
                this.TempData["Success"] = "Unsuccessfull operation!";

                InitializeBorrowers();
                return Page();
            }

            return RedirectToPage("/Index");
        }

        private void InitializeBorrowers()
        {
            this.ViewData["BorrowerId"] = new SelectList(this.context.Borrowers, "Id", "Name");
        }
    }
}