CopilotChat: Options pattern and best practices (#588)

### Motivation and Context
Aligning CopilotChat further down the path of a reference application.

### Description
- Refactored configurations to use Options pattern as a best practice.
- Moved to use Kestral appsettings for the endpoint and we now report
the endpoint after the application starts, which will account for any
configuration changes that may have occurred.
- Moved web and service builder extensions to their own files to slim
down `Program.cs` and make it easier to understand each set of
extensions. This is mostly to separate out those extensions related to
Semantic Kernel so developers can find those code sections more easily.
- Renamed bot from "SK Chatbot" to "Copilot" to align with the project
name.

Author: adrianwyatt

samples/apps/copilot-chat-app/README.md

@@ -132,4 +132,4 @@ the complete list of current models supporting chat completions.
 
 ## Additional resources
 
-1. [Import Document Application](./importdocument/README.md): Ingest a document to memory.
+1. [Import Document Application](./importdocument/README.md): Import a document to the memory store.

samples/apps/copilot-chat-app/webapi/Config/AIServiceConfig.cs

@@ -0,0 +1,53 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ComponentModel.DataAnnotations;
+
+namespace SemanticKernel.Service.Config;
+
+/// <summary>
+/// Configuration options for AI services, such as Azure OpenAI and OpenAI.
+/// </summary>
+public sealed class AIServiceOptions
+{
+    public const string CompletionPropertyName = "Completion";
+    public const string EmbeddingPropertyName = "Embedding";
+
+    public enum AIServiceType
+    {
+        AzureOpenAI,
+        OpenAI
+    }
+
+    /// <summary>
+    /// Label used for referencing the AI service in Semantic Kernel.
+    /// </summary>
+    [Required, NotEmptyOrWhitespace]
+    public string Label { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Type of AI service.
+    /// </summary>
+    [Required]
+    public AIServiceType AIService { get; set; } = AIServiceType.AzureOpenAI;
+
+    /// <summary>
+    /// Azure OpenAI deployment name or OpenAI model name.
+    /// </summary>
+    [Required, NotEmptyOrWhitespace]
+    public string DeploymentOrModelId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// (Azure OpenAI only) Azure OpenAI endpoint.
+    /// </summary>
+    [RequiredOnPropertyValue(nameof(AIService), AIServiceType.AzureOpenAI)]
+    [NotEmptyOrWhitespace]
+    public string Endpoint { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Key to access the AI service.
+    /// </summary>
+    [Required, NotEmptyOrWhitespace]
+    public string Key { get; set; } = string.Empty;
+
+    // TODO support OpenAI's orgID
+}

samples/apps/copilot-chat-app/webapi/Config/AIServiceOptions.cs

@@ -0,0 +1,68 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ComponentModel.DataAnnotations;
+using Microsoft.Identity.Web;
+
+namespace SemanticKernel.Service.Config;
+
+/// <summary>
+/// Configuration options for authorizing to the service.
+/// </summary>
+public class AuthorizationOptions
+{
+    public const string PropertyName = "Authorization";
+
+    public enum AuthorizationType
+    {
+        None,
+        ApiKey,
+        AzureAd
+    }
+
+    /// <summary>
+    /// Type of authorization.
+    /// </summary>
+    public AuthorizationType Type { get; set; } = AuthorizationType.None;
+
+    /// <summary>
+    /// When <see cref="Type"/> is <see cref="AuthorizationType.ApiKey"/>, this is the API key to use.
+    /// </summary>
+    [Required, NotEmptyOrWhitespace]
+    public string ApiKey { get; set; } = string.Empty;
+
+    /// <summary>
+    /// When <see cref="Type"/> is <see cref="AuthorizationType.AzureAd"/>, these are the Azure AD options to use.
+    /// </summary>
+    [RequiredOnPropertyValue(nameof(Type), AuthorizationType.AzureAd)]
+    public AzureAdOptions? AzureAd { get; set; }
+
+    /// <summary>
+    /// Configuration options for Azure Active Directory (AAD) authorization.
+    /// </summary>
+    public class AzureAdOptions
+    {
+        /// <summary>
+        /// AAD instance url, i.e., https://login.microsoftonline.com/
+        /// </summary>
+        [Required, NotEmptyOrWhitespace]
+        public string Instance { get; set; } = string.Empty;
+
+        /// <summary>
+        /// Tenant (directory) ID
+        /// </summary>
+        [Required, NotEmptyOrWhitespace]
+        public string TenantId { get; set; } = string.Empty;
+
+        /// <summary>
+        /// Application (client) ID
+        /// </summary>
+        [Required, NotEmptyOrWhitespace]
+        public string ClientId { get; set; } = string.Empty;
+
+        /// <summary>
+        /// Required scopes.
+        /// </summary>
+        [Required]
+        public string? Scopes { get; set; } = string.Empty;
+    }
+}

samples/apps/copilot-chat-app/webapi/Config/AuthorizationOptions.cs

@@ -0,0 +1,25 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ComponentModel.DataAnnotations;
+
+namespace SemanticKernel.Service.Config;
+
+/// <summary>
+/// Configuration options for Azure speech recognition.
+/// </summary>
+public sealed class AzureSpeechOptions
+{
+    public const string PropertyName = "AzureSpeech";
+
+    /// <summary>
+    /// Location of the Azure speech service to use (e.g. "South Central US")
+    /// </summary>
+    [Required, NotEmptyOrWhitespace]
+    public string? Region { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Key to access the Azure speech service.
+    /// </summary>
+    [Required, NotEmptyOrWhitespace]
+    public string Key { get; set; } = string.Empty;
+}

samples/apps/copilot-chat-app/webapi/Config/AzureSpeechConfig.cs

@@ -1,19 +1,25 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System.ComponentModel.DataAnnotations;
+
 namespace SemanticKernel.Service.Config;
 
 /// <summary>
-/// Configuration settings for the bot file schema that is supported by this application.
+/// Configuration options for the bot file schema that is supported by this application.
 /// </summary>
-public class BotSchemaConfig
+public class BotSchemaOptions
 {
+    public const string PropertyName = "BotSchema";
+
     /// <summary>
     /// The name of the schema.
     /// </summary>
+    [Required, NotEmptyOrWhitespace]
     public string Name { get; set; } = string.Empty;
 
     /// <summary>
     /// The version of the schema.
     /// </summary>
-    public int Version { get; set; } = -1;
+    [Range(0, int.MaxValue)]
+    public int Version { get; set; }
 }

samples/apps/copilot-chat-app/webapi/Config/AzureSpeechOptions.cs

@@ -1,12 +1,16 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using static SemanticKernel.Service.Config.AuthorizationOptions;
+
 namespace SemanticKernel.Service.Config;
 
 /// <summary>
 /// Configuration settings for the chat store.
 /// </summary>
-public class ChatStoreConfig
+public class ChatStoreOptions
 {
+    public const string PropertyName = "ChatStore";
+
     /// <summary>
     /// The type of chat store to use.
     /// </summary>
@@ -36,10 +40,12 @@ public enum ChatStoreType
     /// <summary>
     /// Gets or sets the configuration for the file system chat store.
     /// </summary>
-    public FileSystemConfig? Filesystem { get; set; }
+    [RequiredOnPropertyValue(nameof(Type), ChatStoreType.Filesystem)]
+    public FileSystemOptions? Filesystem { get; set; }
 
     /// <summary>
     /// Gets or sets the configuration for the Azure CosmosDB chat store.
     /// </summary>
-    public CosmosConfig? Cosmos { get; set; }
+    [RequiredOnPropertyValue(nameof(Type), ChatStoreType.Cosmos)]
+    public CosmosOptions? Cosmos { get; set; }
 }