Interface for recommendation service (#373)

* Interface for recommendation service

* Make Process abstract

Author: isra-fel

src/Common/AzurePSCmdlet.cs

@@ -56,7 +56,7 @@ public abstract class AzurePSCmdlet : PSCmdlet, IDisposable
         // Using Ansi Code to control font color(97(Bold White)) and background color(0;120;212(RGB))
         private static readonly string ansiCodePrefix = "\u001b[97;48;2;0;120;212m";
 
-        // using '[k' for erase in line. '[0m' to ending ansi code  
+        // using '[k' for erase in line. '[0m' to ending ansi code
         private static readonly string ansiCodeSuffix = "\u001b[K\u001b[0m";
 
         protected AzurePSDataCollectionProfile _dataCollectionProfile
@@ -386,8 +386,10 @@ private void WriteBreakingChangeOrPreviewMessage()
         /// </summary>
         protected override void EndProcessing()
         {
-            if (MetricHelper.IsCalledByUser() 
-                && SurveyHelper.GetInstance().ShouldPromptAzSurvey() 
+            WriteEndProcessingRecommendation();
+
+            if (MetricHelper.IsCalledByUser()
+                && SurveyHelper.GetInstance().ShouldPromptAzSurvey()
                 && (AzureSession.Instance.TryGetComponent<IConfigManager>(nameof(IConfigManager), out var configManager)
                 && !configManager.GetConfigValue<bool>(ConfigKeysForCommon.EnableInterceptSurvey).Equals(false)))
             {
@@ -413,6 +415,13 @@ protected override void EndProcessing()
             base.EndProcessing();
         }
 
+        private void WriteEndProcessingRecommendation()
+        {
+            if (AzureSession.Instance.TryGetComponent<IEndProcessingRecommendationService>(nameof(IEndProcessingRecommendationService), out var service))
+            {
+                service.Process(this, MyInvocation, _qosEvent);
+            }
+        }
 
         protected string CurrentPath()
         {

src/Common/IEndProcessingRecommendationService.cs

@@ -0,0 +1,33 @@
+// ----------------------------------------------------------------------------------
+//
+// 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 System.Management.Automation;
+
+namespace Microsoft.WindowsAzure.Commands.Utilities.Common
+{
+    /// <summary>
+    /// A service to give recommendations based on the input of the user.
+    /// For example we could recommend a region which costs less.
+    /// </summary>
+    public abstract class IEndProcessingRecommendationService
+    {
+        /// <summary>
+        /// Process the cmdlet execution and display recommendation messages if any.
+        /// </summary>
+        /// <param name="azurePSCmdlet">Cmdlet instance, for writing messages.</param>
+        /// <param name="myInvocation">Contains info about cmdlet, module, parameters.</param>
+        /// <param name="_qosEvent">To record successful recommendation.</param>
+        public abstract void Process(AzurePSCmdlet azurePSCmdlet, InvocationInfo myInvocation, AzurePSQoSEvent _qosEvent);
+    }
+}

src/Common/MetricHelper.cs

@@ -119,7 +119,7 @@ public string HashMacAddress
                         try
                         {
                             var macAddress = _networkHelper.GetMACAddress();
-                            _hashMacAddress = string.IsNullOrWhiteSpace(macAddress) 
+                            _hashMacAddress = string.IsNullOrWhiteSpace(macAddress)
                                 ? null : GenerateSha256HashString(macAddress)?.Replace("-", string.Empty)?.ToLowerInvariant();
                         }
                         catch
@@ -255,7 +255,7 @@ private void LogExceptionEvent(AzurePSQoSEvent qos)
                 Dictionary<string, string> eventProperties = new Dictionary<string, string>();
                 LoadTelemetryClientContext(qos, client.Context);
                 PopulatePropertiesFromQos(qos, eventProperties);
-                // qos.Exception contains exception message which may contain Users specific data. 
+                // qos.Exception contains exception message which may contain Users specific data.
                 // We should not collect users specific data.
                 eventProperties.Add("Message", "Message removed due to PII.");
                 eventProperties.Add("StackTrace", qos.Exception.StackTrace);
@@ -401,7 +401,7 @@ private void PopulatePropertiesFromQos(AzurePSQoSEvent qos, IDictionary<string,
                                                     ? qos.Exception.Data[AzurePSErrorDataKeys.ErrorKindKey].ToString()
                                                     : null;
                         cloudErrorCode = (string)qos.Exception.Data[AzurePSErrorDataKeys.CloudErrorCodeKey];
-                        // For the time being, we consider ResourceNotFound and ResourceGroupNotFound as user's input error. 
+                        // For the time being, we consider ResourceNotFound and ResourceGroupNotFound as user's input error.
                         // We are considering if ResourceNotFound should be false positive error.
                         if (("ResourceNotFound".Equals(cloudErrorCode) || "ResourceGroupNotFound".Equals(cloudErrorCode))
                             && existingErrorKind != ErrorKind.FalseError)
@@ -413,7 +413,7 @@ private void PopulatePropertiesFromQos(AzurePSQoSEvent qos, IDictionary<string,
                     StringBuilder sb = new StringBuilder();
                     foreach (var key in qos.Exception.Data?.Keys)
                     {
-                        if (AzurePSErrorDataKeys.IsKeyPredefined(key.ToString()) 
+                        if (AzurePSErrorDataKeys.IsKeyPredefined(key.ToString())
                             && !AzurePSErrorDataKeys.HttpStatusCode.Equals(key))
                         {
                             if (sb.Length > 0)
@@ -481,8 +481,8 @@ private static string ConvertFrameToString(System.Diagnostics.StackFrame frame)
 
         public bool IsMetricTermAccepted()
         {
-            return _profile != null 
-                && _profile.EnableAzureDataCollection.HasValue 
+            return _profile != null
+                && _profile.EnableAzureDataCollection.HasValue
                 && _profile.EnableAzureDataCollection.Value;
         }
 
@@ -604,6 +604,12 @@ public class AzurePSQoSEvent
     public string TenantId { get; set; }
     public bool SurveyPrompted { get; set; }
 
+    /// <summary>
+    /// Appear in certain resource creation commands like New-AzVM. See RegionalRecommender (PS repo).
+    /// Represent the recommended region if we do have recommendation.
+    /// </summary>
+    public string DisplayRegionIdentified { get; set; }
+
     public string ParameterSetName { get; set; }
     public string InvocationName { get; set; }
     public Dictionary<string, string> CustomProperties { get; private set; }
@@ -637,8 +643,8 @@ public void FinishQosEvent()
     public override string ToString()
     {
         StringBuilder sb = new StringBuilder("AzureQoSEvent: ");
-        if (ShowTelemetry) 
-        {   
+        if (ShowTelemetry)
+        {
             foreach(PropertyDescriptor descriptor in TypeDescriptor.GetProperties((this)))
                 {
                     string name = descriptor.Name;
@@ -652,7 +658,7 @@ public override string ToString()
         {
             sb = sb.Append($" Module: {ModuleName}:{ModuleVersion}; CommandName: {CommandName}; PSVersion: {PSVersion}");
         }
-        
+
         sb.Append($"; IsSuccess: {IsSuccess}; Duration: {Duration}");
 
         if (Exception != null)