Address review comments

src/Authentication.Abstractions/AuthenticationInfo.cs → src/Authentication.Abstractions/AuthTelemetryRecord.cs

@@ -12,15 +12,18 @@
 // limitations under the License.
 // ----------------------------------------------------------------------------------
 
-using System.Collections.Concurrent;
+using Newtonsoft.Json;
+
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
-using System.Xml.Serialization;
-using Newtonsoft.Json;
 
 namespace Microsoft.Azure.Commands.Common.Authentication.Abstractions
 {
-    public class AuthenticationInfo : IAuthenticationInfo
+    /// <summary>
+    /// A model class for authenction telemetry record.
+    /// </summary>
+    public class AuthTelemetryRecord : IAuthTelemetryRecord
     {
         /// <summary>
         /// Class name of the TokenCredential, stands for the authentication method
@@ -36,15 +39,14 @@ public class AuthenticationInfo : IAuthenticationInfo
         /// Additional properties for AuthenticationInfo
         /// </summary>
         [JsonIgnore]
-        [XmlIgnore]
         public IDictionary<string, string> ExtendedProperties { get; } = new ConcurrentDictionary<string, string>(StringComparer.OrdinalIgnoreCase);
 
-        public AuthenticationInfo()
+        public AuthTelemetryRecord()
         {
             TokenCredentialName = null;
         }
 
-        public AuthenticationInfo(IAuthenticationInfo other, bool? isSuccess = null)
+        public AuthTelemetryRecord(IAuthTelemetryRecord other, bool? isSuccess = null)
         {
             this.TokenCredentialName = other.TokenCredentialName;
             this.AuthenticationSuccess = isSuccess ?? other.AuthenticationSuccess;
@@ -59,8 +61,14 @@ public AuthenticationInfo(IAuthenticationInfo other, bool? isSuccess = null)
         /// </summary>
         public const string TokenCacheEnabled = "TokenCacheEnabled";
 
+        /// <summary>
+        /// Prefix of properties of the first record of authentication telemetry record.
+        /// </summary>
         public const string AuthInfoTelemetryHeadKey = "auth-info-head";
 
+        /// <summary>
+        /// Key of the left records of authentication telemetry.
+        /// </summary>
         public const string AuthInfoTelemetrySubsequentKey = "auth-info-sub";
     }
 }

src/Authentication.Abstractions/AuthenticationTelemetry.cs

@@ -0,0 +1,48 @@
+// ----------------------------------------------------------------------------------
+//
+// 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.Collections.Generic;
+
+namespace Microsoft.Azure.Commands.Common.Authentication.Abstractions
+{
+    /// <summary>
+    /// A model class for a list of authenction telemetry records.
+    /// </summary>
+    public class AuthenticationTelemetry
+    {
+        /// <summary>
+        /// The first record of authentication telemetry data, usually describes the main method of this authentication process.
+        /// </summary>
+        public IAuthTelemetryRecord Head { get; } = null;
+
+        /// <summary>
+        /// The left part of authentication telemetry records.
+        /// </summary>
+        public IList<IAuthTelemetryRecord> Tail { get; } = new List<IAuthTelemetryRecord>();
+
+        public AuthenticationTelemetry(IEnumerable<IAuthTelemetryRecord> records)
+        {
+            var enumerator = records.GetEnumerator();
+            if (enumerator.MoveNext())
+            {
+                Head = enumerator.Current;
+            }
+
+            while (enumerator.MoveNext())
+            {
+                Tail.Add(enumerator.Current);
+            }
+        }
+    }
+}

src/Authentication.Abstractions/Interfaces/IAuthenticationInfo.cs → src/Authentication.Abstractions/Interfaces/IAuthTelemetryRecord.cs

@@ -14,7 +14,10 @@
 
 namespace Microsoft.Azure.Commands.Common.Authentication.Abstractions
 {
-    public interface IAuthenticationInfo : IExtensibleModel
+    /// <summary>
+    /// Representation of an authentication telemetry record
+    /// </summary>
+    public interface IAuthTelemetryRecord : IExtensibleModel
     {
         /// <summary>
         /// Class name of the TokenCredential, stands for the authentication method

src/Authentication.Abstractions/Interfaces/IAuthenticationFactory.cs

@@ -99,6 +99,6 @@ IAccessToken Authenticate(
         /// <summary>
         /// Get the information to be recorded in Telemetry
         /// </summary>
-        IList<IAuthenticationInfo> GetDataForTelemetry();
+        AuthenticationTelemetry GetDataForTelemetry();
     }
 }

src/Common/AzurePSCmdlet.cs

@@ -431,8 +431,6 @@ protected override void EndProcessing()
             WriteWarningMessageForVersionUpgrade();
             WriteSecretsWarningMessage();
 
-            _qosEvent.AuthInfo = AzureSession.Instance.AuthenticationFactory.GetDataForTelemetry();
-
             if (MetricHelper.IsCalledByUser()
                 && SurveyHelper.GetInstance().ShouldPromptAzSurvey()
                 && (AzureSession.Instance.TryGetComponent<IConfigManager>(nameof(IConfigManager), out var configManager)
@@ -845,6 +843,7 @@ protected void LogQosEvent()
 
             _qosEvent.ParameterSetName = this.ParameterSetName;
             _qosEvent.FinishQosEvent();
+            _qosEvent.AuthTelemetry = AzureSession.Instance.AuthenticationFactory.GetDataForTelemetry();
 
             if (!IsUsageMetricEnabled && (!IsErrorMetricEnabled || _qosEvent.IsSuccess))
             {

src/Common/MetricHelper.cs

@@ -292,28 +292,18 @@ public void SetPSHost(PSHost host)
         {
         }
 
-        private static void PopulateAuthenticationInfoFromQos(IEnumerable<IAuthenticationInfo> infos, IDictionary<string, string> eventProperties)
+        private static void PopulateAuthenticationPropertiesFromQos(AuthenticationTelemetry telemetry, IDictionary<string, string> eventProperties)
         {
-            var enumerator = infos.GetEnumerator();
-            if (enumerator.MoveNext())
-            {
-                var info = enumerator.Current;
-                eventProperties[$"{AuthenticationInfo.AuthInfoTelemetryHeadKey}-{nameof(info.TokenCredentialName).ToLower()}"] = info.TokenCredentialName;
-                eventProperties[$"{AuthenticationInfo.AuthInfoTelemetryHeadKey}-{nameof(info.AuthenticationSuccess).ToLower()}"] = info.AuthenticationSuccess.ToString();
-
-                foreach (var property in info.ExtendedProperties)
-                {
-                    eventProperties[$"{AuthenticationInfo.AuthInfoTelemetryHeadKey}-{property.Key.ToLower()}"] = property.Value;
-                }
-            }
+            var record = telemetry.Head;
+            eventProperties[$"{AuthTelemetryRecord.AuthInfoTelemetryHeadKey}-{nameof(record.TokenCredentialName).ToLower()}"] = record.TokenCredentialName;
+            eventProperties[$"{AuthTelemetryRecord.AuthInfoTelemetryHeadKey}-{nameof(record.AuthenticationSuccess).ToLower()}"] = record.AuthenticationSuccess.ToString();
 
-            var subAuthInfos = new List<AuthenticationInfo>();
-            while (enumerator.MoveNext())
+            foreach (var property in record.ExtendedProperties)
             {
-                var info = enumerator.Current;
-                subAuthInfos.Add(info as AuthenticationInfo);
+                eventProperties[$"{AuthTelemetryRecord.AuthInfoTelemetryHeadKey}-{property.Key.ToLower()}"] = property.Value;
             }
-            eventProperties[AuthenticationInfo.AuthInfoTelemetrySubsequentKey] = JsonConvert.SerializeObject(subAuthInfos);
+
+            eventProperties[AuthTelemetryRecord.AuthInfoTelemetrySubsequentKey] = JsonConvert.SerializeObject(telemetry.Tail);
         }
 
         private void PopulatePropertiesFromQos(AzurePSQoSEvent qos, IDictionary<string, string> eventProperties, bool populateException = false)
@@ -478,7 +468,7 @@ private void PopulatePropertiesFromQos(AzurePSQoSEvent qos, IDictionary<string,
 
             PopulateConfigMetricsFromQos(qos, eventProperties);
             PopulateSanitizerPropertiesFromQos(qos, eventProperties);
-            PopulateAuthenticationInfoFromQos(qos.AuthInfo, eventProperties);
+            PopulateAuthenticationPropertiesFromQos(qos.AuthTelemetry, eventProperties);
 
             if (qos.InputFromPipeline != null)
             {
@@ -703,7 +693,7 @@ public class AzurePSQoSEvent
 
     public SanitizerTelemetry SanitizerInfo { get; set; }
 
-    public IEnumerable<IAuthenticationInfo> AuthInfo { get; set; }
+    public AuthenticationTelemetry AuthTelemetry { get; set; }
 
     public AzurePSQoSEvent()
     {