netmash/NDB.Test.Api/Extensions/AuthenticationExtensions.cs

using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using NDB.Security.Authentication.Identity;
using NDB.Security.Authentication.Identity.Models;
using System.Linq;

namespace NDB.Test.Api.Extensions
{
    public static class AuthenticationExtensions
    {
        private record GuestRoute(string Route, int PathElements);
        private static readonly GuestRoute[] _resourcesRoutes = new GuestRoute[]
        {
            new GuestRoute("/resources", 1),
            new GuestRoute("/images", 1),
            new GuestRoute("/spot", 2)
        };

        public static IServiceCollection AddIdentityAuthentication(this IServiceCollection services, string identityServerBaseAddress)
        {
            var authenticationOptions = new AuthenticationOptions()
            {
                AuthenticateAsGuest = (HttpRequest request) =>
                {
                    var authenticateAsGuest = AuthenticateAsGuest(request);
                    return authenticateAsGuest;
                },
                GuestUserName = "Guest",
                GuestUserId = -111,
                AcceptTokenFromQuery = true
            };

            services.AddIdentityAuthentication(identityServerBaseAddress, authenticationOptions);
            return services;
        }

        private static bool AuthenticateAsGuest(HttpRequest request)
        {
            if (!request.Path.HasValue)
                return false;

            var guestRoute = _resourcesRoutes.FirstOrDefault(z => request.Path.Value.StartsWith(z.Route));
            if (guestRoute == null)
                return false;

            var resourceRequestedById = request.Query.Count > 0 && request.Query.ContainsKey("id");
            if (resourceRequestedById)
                return false;

            var resourceRequestedByCode = request.Query.Count > 0 && request.Query.ContainsKey("code");
            if (resourceRequestedByCode)
                return true;

            var resourceRequestedByName = request.Path.Value.Replace(guestRoute.Route, string.Empty).Substring(1).Split("/").Length == guestRoute.PathElements;
            if (resourceRequestedByName)
                return true;

            return false;
        }
    }
}