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src/Yavsc/Helpers/AuthHelpers.cs

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+using System;
+using System.Linq;
+using System.Collections.Generic;
+using Microsoft.AspNet.Http;
+using Yavsc.ViewModels.Account;
+
+namespace Yavsc.Helpers
+{
+    public static class HttpContextExtensions {
+        public static IEnumerable<YaAuthenticationDescription> GetExternalProviders(this HttpContext context) {
+            if (context == null) {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            return from description in context.Authentication.GetAuthenticationSchemes()
+                   where !string.IsNullOrEmpty(description.DisplayName)
+                   select 
+                            ( new YaAuthenticationDescription 
+                            {
+                                DisplayName = description.DisplayName,
+                                AuthenticationScheme = description.AuthenticationScheme,
+                                Items = description.Items
+                            });;
+        }
+
+        public static bool IsProviderSupported(this HttpContext context, string provider) {
+            if (context == null) {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            return (from description in context.GetExternalProviders()
+                    where string.Equals(description.AuthenticationScheme, provider, StringComparison.OrdinalIgnoreCase)
+                    select description).Any();
+        }
+    }
+
+
+}