[Text Analytics] Add support for abstractive summarization (#32402)

- Added `TextAnalyticsActions.AbstractSummaryActions` to perform abstractive summarization in a batch of actions.
- Added `TextAnalyticsClient.StartAbstractSummary` and `StartAbstractSummaryAsync` to perform abstractive summarization on a collection of documents.

sdk/textanalytics/Azure.AI.TextAnalytics/CHANGELOG.md

@@ -9,6 +9,8 @@
 - Added `WellKnownFhirVersion` and `HealthcareDocumentType` enums.
 - Added `TextAnalyticsActions.ExtractSummaryActions` to perform extractive summarization in a batch of actions.
 - Added `TextAnalyticsClient.StartExtractSummary` and `StartExtractSummaryAsync` to perform extractive summarization on a collection of documents.
+- Added `TextAnalyticsActions.AbstractSummaryActions` to perform abstractive summarization in a batch of actions.
+- Added `TextAnalyticsClient.StartAbstractSummary` and `StartAbstractSummaryAsync` to perform abstractive summarization on a collection of documents.
 - Added `Script` property to `DetectedLanguage`.
 - Added `ScriptKind` enum.
 - Added the `CategorizedEntity.Resolutions` property.

sdk/textanalytics/Azure.AI.TextAnalytics/src/AbstractSummaryAction.cs

@@ -0,0 +1,61 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+namespace Azure.AI.TextAnalytics
+{
+    /// <summary>
+    /// A set of options used to configure abstractive summarization, including the model version to use, the maximum
+    /// number of sentences that the resulting summary can have, and more.
+    /// </summary>
+    public class AbstractSummaryAction
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AbstractSummaryAction"/> class.
+        /// </summary>
+        public AbstractSummaryAction()
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AbstractSummaryAction"/> class based on the given
+        /// <see cref="AbstractSummaryOptions"/>. It sets the <see cref="ModelVersion"/>,
+        /// <see cref="DisableServiceLogs"/>, and <see cref="MaxSentenceCount"/> properties.
+        /// </summary>
+        public AbstractSummaryAction(AbstractSummaryOptions options)
+        {
+            ModelVersion = options.ModelVersion;
+            DisableServiceLogs = options.DisableServiceLogs;
+            MaxSentenceCount = options.MaxSentenceCount;
+        }
+
+        /// <summary>
+        /// The version of the text analytics model that will be used to generate the result. To learn more about the
+        /// supported model versions for each feature, see
+        /// <see href="https://learn.microsoft.com/azure/cognitive-services/language-service/concepts/model-lifecycle"/>.
+        /// </summary>
+        public string ModelVersion { get; set; }
+
+        /// <summary>
+        /// Indicates whether the service logs your input text for 48 hours, which is solely to allow for
+        /// troubleshooting, if needed. Setting this property to <c>true</c> disables input logging and may limit our
+        /// ability to investigate any issues that occur. If not set, the service default is used.
+        /// <para>
+        /// Please see the Cognitive Services Compliance and Privacy notes at
+        /// <see href="https://aka.ms/cs-compliance"/> for additional details, and the Microsoft Responsible AI
+        /// principles at <see href="https://www.microsoft.com/ai/responsible-ai"/>.
+        /// </para>
+        /// </summary>
+        public bool? DisableServiceLogs { get; set; }
+
+        /// <summary>
+        /// The name of this action. If not set, the service will generate one.
+        /// </summary>
+        public string ActionName { get; set; }
+
+        /// <summary>
+        /// The maximum number of sentences that the resulting summaries can have. If not set, the service default is
+        /// used.
+        /// </summary>
+        public int? MaxSentenceCount { get; set; }
+    }
+}

sdk/textanalytics/Azure.AI.TextAnalytics/src/AbstractSummaryActionResult.cs

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System;
+using Azure.AI.TextAnalytics.Models;
+
+namespace Azure.AI.TextAnalytics
+{
+    /// <summary>
+    /// A representation of the result of performing an <see cref="AbstractSummaryAction"/> on a given set of
+    /// documents.
+    /// </summary>
+    public class AbstractSummaryActionResult : TextAnalyticsActionResult
+    {
+        private readonly AbstractSummaryResultCollection _documentsResults;
+
+        /// <summary>
+        /// Initializes a successful <see cref="AbstractSummaryActionResult"/>.
+        /// </summary>
+        internal AbstractSummaryActionResult(
+            AbstractSummaryResultCollection result, string actionName, DateTimeOffset completedOn)
+            : base(actionName, completedOn)
+        {
+            _documentsResults = result;
+        }
+
+        /// <summary>
+        /// Initializes an <see cref="AbstractSummaryActionResult"/> with an error.
+        /// </summary>
+        internal AbstractSummaryActionResult(string actionName, DateTimeOffset completedOn, Error error)
+            : base(actionName, completedOn, error) { }
+
+        /// <summary>
+        /// The collection of results corresponding to each given document.
+        /// </summary>
+        public AbstractSummaryResultCollection DocumentsResults
+        {
+            get
+            {
+                if (HasError)
+                {
+                    throw new InvalidOperationException(
+                        $"Cannot access the results of this action, due to error {Error.ErrorCode}: {Error.Message}");
+                }
+                return _documentsResults;
+            }
+        }
+    }
+}