add method to IAuthenticationFactory, add interface IAzureSessionComponentListener, fix namespace for Base64UrlHelper (#242)

* add method to IAuthenticationFactory, add interface IAzureSessionCOmponentListener, fix namespace for Base64UrlHelper

* remove unused constant

* fix handler name

* resolve comments

Author: VeryEarly

src/Authentication.Abstractions/AzureSession.cs

@@ -18,6 +18,7 @@
 using System.Threading;
 using System.Diagnostics;
 using System.Collections.Concurrent;
+using Microsoft.Azure.Commands.Common.Authentication.Abstractions.Models;
 
 namespace Microsoft.Azure.Commands.Common.Authentication
 {
@@ -30,6 +31,7 @@ public abstract class AzureSession : IAzureSession
         static bool _initialized = false;
         static ReaderWriterLockSlim sessionLock = new ReaderWriterLockSlim(LockRecursionPolicy.SupportsRecursion);
         private IDictionary<ComponentKey, object> _componentRegistry = new ConcurrentDictionary<ComponentKey, object>(new ComponentKeyComparer());
+        private event EventHandler<AzureSessionEventArgs> _eventHandler;
 
         /// <summary>
         /// Gets or sets Azure client factory.
@@ -218,7 +220,7 @@ public bool TryGetComponent<T>(string componentName, out T component) where T :
 
         public void RegisterComponent<T>(string componentName, Func<T> componentInitializer) where T : class
         {
-            RegisterComponent(componentName, componentInitializer, false); ;
+            RegisterComponent(componentName, componentInitializer, false);
         }
 
         public void RegisterComponent<T>(string componentName, Func<T> componentInitializer, bool overwrite) where T : class
@@ -229,7 +231,20 @@ public void RegisterComponent<T>(string componentName, Func<T> componentInitiali
                     var key = new ComponentKey(componentName, typeof(T));
                     if (!_componentRegistry.ContainsKey(key) || overwrite)
                     {
-                        _componentRegistry[key] = componentInitializer();
+                        if (_componentRegistry.ContainsKey(key) && overwrite)
+                        {
+                            var existed = _componentRegistry[key];
+                            if (existed is IAzureSessionListener existedListener)
+                            {
+                                _eventHandler -= existedListener.OnEvent;
+                            }
+                        }
+                        var component = componentInitializer();
+                        _componentRegistry[key] = component;
+                        if (component is IAzureSessionListener listener)
+                        {
+                            _eventHandler += listener.OnEvent;
+                        }
                     }
                 });
         }
@@ -242,16 +257,37 @@ public void UnregisterComponent<T>(string componentName) where T : class
                     var key = new ComponentKey(componentName, typeof(T));
                     if (_componentRegistry.ContainsKey(key))
                     {
+                        var component = _componentRegistry[key];
+                        if (component is IAzureSessionListener listener)
+                        {
+                            _eventHandler -= listener.OnEvent;
+                        }
                         _componentRegistry.Remove(key);
                     }
                 });
         }
 
         public void ClearComponents()
         {
+            ChangeRegistry(ClearHandlers);
             ChangeRegistry(_componentRegistry.Clear);
         }
 
+        private void ClearHandlers()
+        {
+            _eventHandler = null;
+        }
+
+        public void RaiseContextClearedEvent()
+        {
+            OnEvent(new AzureSessionEventArgs(AzureSessionEventType.ContextCleared));
+        }
+
+        protected virtual void OnEvent(AzureSessionEventArgs e)
+        {
+            _eventHandler?.Invoke(this, e);
+        }
+
         void ChangeRegistry(Action changeAction)
         {
             changeAction();

src/Authentication.Abstractions/Interfaces/IAuthenticationFactory.cs

@@ -80,6 +80,14 @@ IAccessToken Authenticate(
         /// <returns>AutoRest client crentials targeting the given context and endpoint</returns>
         ServiceClientCredentials GetServiceClientCredentials(IAzureContext context, string targetEndpoint);
 
+        /// <summary>
+        /// Get service client credentials with initial token and delegate for renewing
+        /// </summary>
+        /// <param name="token">Initial token for credential</param>
+        /// <param name="function">Delegate for renewing token</param>
+        /// <returns>Service client credentials</returns>
+        ServiceClientCredentials GetServiceClientCredentials(string accessToken, Func<string> renew = null);
+
         /// <summary>
         /// Remove any stored credentials for the given user
         /// </summary>

src/Authentication.Abstractions/Interfaces/IAzureSession.cs

@@ -126,6 +126,11 @@ public interface IAzureSession : IExtensibleModel
         /// </summary>
         void ClearComponents();
 
+        /// <summary>
+        /// Remove components from the session shared component registry with on clear-azcontext event
+        /// </summary>
+        void RaiseContextClearedEvent();
+
         /// <summary>
         /// The trace level for authentication
         /// </summary>

src/Authentication.Abstractions/Interfaces/IAzureSessionListener.cs

@@ -0,0 +1,24 @@
+// ----------------------------------------------------------------------------------
+//
+// Copyright Microsoft Corporation
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ----------------------------------------------------------------------------------
+
+using Microsoft.Azure.Commands.Common.Authentication.Abstractions.Models;
+using System;
+
+namespace Microsoft.Azure.Commands.Common.Authentication.Abstractions
+{
+    public interface IAzureSessionListener
+    {
+        void OnEvent(object sender, AzureSessionEventArgs e);
+    }
+}

src/Authentication.Abstractions/Models/AzureSessionEventArgs.cs

@@ -0,0 +1,27 @@
+using System;
+// ----------------------------------------------------------------------------------
+//
+// Copyright Microsoft Corporation
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ----------------------------------------------------------------------------------
+
+namespace Microsoft.Azure.Commands.Common.Authentication.Abstractions.Models
+{
+    public class AzureSessionEventArgs : EventArgs
+    {
+        public AzureSessionEventType Type { get; private set; }
+
+        public AzureSessionEventArgs(AzureSessionEventType type)
+        {
+            this.Type = type;
+        }
+    }
+}

src/Authentication.Abstractions/Models/AzureSessionEventType.cs

@@ -0,0 +1,21 @@
+// ----------------------------------------------------------------------------------
+//
+// Copyright Microsoft Corporation
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ----------------------------------------------------------------------------------
+
+namespace Microsoft.Azure.Commands.Common.Authentication.Abstractions.Models
+{
+    public enum AzureSessionEventType
+    {
+        ContextCleared
+    }
+}

src/Common/Constants.cs

@@ -28,12 +28,6 @@ public static class ApiConstants
 
     }
 
-    public static class SharedComponentKeys
-    {
-        //Will be stored in AzureSession and shared between Az.ContainerRegistry and Az.Accounts
-        public const string AcrTokenCacheKey = "AcrTokenCache";   
-    }
-
     public static class StorSimpleConstants
     {
         public const string DefaultStorageAccountEndpoint = "core.windows.net";

src/Common/Utilities/Base64UrlHelper.cs

@@ -16,7 +16,7 @@
 using System.Globalization;
 using System.Text;
 
-namespace Microsoft.Azure.Commands.Profile.Utilities
+namespace Microsoft.WindowsAzure.Commands.Utilities.Common
 {
     //The source code is copied from https://github.com/AzureAD/microsoft-authentication-library-for-dotnet/blob/master/src/client/Microsoft.Identity.Client/Utils/Base64UrlHelpers.cs
     public static class Base64UrlHelper