decePubClient/Services/CoalescingStringLocalizer.cs

using decePubClient.Resources;

using Microsoft.Extensions.Localization;

using PrivaPub.ClientModels.Resources;

namespace decePubClient.Services
{
	/// <summary>
	/// The app's localizer: looks a key up in Resources/AllStrings, then in PrivaPub.ClientModels' FieldsNameResource and
	/// ErrorsResource, and falls back to the key itself (formatted with the arguments), so a missing key shows its
	/// English text instead of failing.
	/// </summary>
	public sealed class CoalescingStringLocalizer(IStringLocalizer<AllStrings> baseLocalizer, IStringLocalizer<FieldsNameResource> fieldsLocalizer,
		IStringLocalizer<ErrorsResource> errorsLocalizer)
	{
		public IStringLocalizer Base => baseLocalizer;
		public IStringLocalizer Fields => fieldsLocalizer;
		public IStringLocalizer Errors => errorsLocalizer;

		public LocalizedString this[string name]
		{
			get
			{
				try
				{
					if (!baseLocalizer[name].ResourceNotFound)
						return baseLocalizer[name];
					if (!fieldsLocalizer[name].ResourceNotFound)
						return fieldsLocalizer[name];
					if (!errorsLocalizer[name].ResourceNotFound)
						return errorsLocalizer[name];
					return new(name, name, true);
				}
				catch (Exception ex)
				{
					Console.WriteLine(ex.ToString());
					return new(name, name, true);
				}
			}
		}

		public LocalizedString this[string name, params object[] arguments]
		{
			get
			{
				try
				{
					if (!baseLocalizer[name].ResourceNotFound)
						return baseLocalizer[name, arguments];
					if (!fieldsLocalizer[name].ResourceNotFound)
						return fieldsLocalizer[name, arguments];
					if (!errorsLocalizer[name].ResourceNotFound)
						return errorsLocalizer[name, arguments];
					return new(name, string.Format(name, arguments), true);
				}
				catch (Exception ex)
				{
					Console.WriteLine(ex.ToString());
					return new(name, name, true);
				}
			}
		}
	}
}