modernkeepass/ModernKeePass/ViewModels/DonateVm.cs

using System.Collections.ObjectModel;
using System.Globalization;
using System.Linq;
using System.Threading.Tasks;
using Windows.ApplicationModel.Store;
using ModernKeePass.Common;
using ModernKeePass.Interfaces;
using ModernKeePass.Services;

namespace ModernKeePass.ViewModels
{
    public class DonateVm: NotifyPropertyChangedBase
    {
        public ObservableCollection<ProductListing> Donations { get; }

        public ProductListing SelectedItem
        {
            get { return _selectedItem; }
            set { SetProperty(ref _selectedItem, value); }
        }

        private readonly ILicenseService _license;
        private ProductListing _selectedItem;

        public DonateVm() : this (new LicenseService()) { }

        public DonateVm(ILicenseService license)
        {
            var usNfi = new NumberFormatInfo
            {
                NegativeSign = "-",
                NumberDecimalSeparator = ".",
                NumberGroupSeparator = ",",
                CurrencySymbol = "$"
            };
            _license = license;
            Donations = new ObservableCollection<ProductListing>(
                _license.Products.Values.OrderBy(p => decimal.Parse(p.FormattedPrice, NumberStyles.Currency, usNfi)));
        }

        public async Task<int> Purchase()
        {
            return await _license.Purchase(SelectedItem.ProductId);
        }
    }
}