.NET: Move SO agent to samples (#3820)

* move SO agent to samples

* change file encoding

* fix files encoding

dotnet/samples/GettingStarted/Agents/Agent_Step05_StructuredOutput/AIAgentBuilderExtensions.cs

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace SampleApp;
+
+/// <summary>
+/// Provides extension methods for adding structured output capabilities to <see cref="AIAgentBuilder"/> instances.
+/// </summary>
+internal static class AIAgentBuilderExtensions
+{
+    /// <summary>
+    /// Adds structured output capabilities to the agent pipeline, enabling conversion of text responses to structured JSON format.
+    /// </summary>
+    /// <param name="builder">The <see cref="AIAgentBuilder"/> to which structured output support will be added.</param>
+    /// <param name="chatClient">
+    /// The chat client used to transform text responses into structured JSON format.
+    /// If <see langword="null"/>, the chat client will be resolved from the service provider.
+    /// </param>
+    /// <param name="optionsFactory">
+    /// An optional factory function that returns the <see cref="StructuredOutputAgentOptions"/> instance to use.
+    /// This allows for fine-tuning the structured output behavior such as setting the response format or system message.
+    /// </param>
+    /// <returns>The <see cref="AIAgentBuilder"/> with structured output capabilities added, enabling method chaining.</returns>
+    /// <remarks>
+    /// <para>
+    /// A <see cref="ChatResponseFormatJson"/> must be specified either through the
+    /// <see cref="AgentRunOptions.ResponseFormat"/> at runtime or the <see cref="StructuredOutputAgentOptions.ChatOptions"/>
+    /// provided during configuration.
+    /// </para>
+    /// </remarks>
+    public static AIAgentBuilder UseStructuredOutput(
+        this AIAgentBuilder builder,
+        IChatClient? chatClient = null,
+        Func<StructuredOutputAgentOptions>? optionsFactory = null)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+
+        return builder.Use((innerAgent, services) =>
+        {
+            chatClient ??= services?.GetService<IChatClient>()
+                ?? throw new InvalidOperationException($"No {nameof(IChatClient)} was provided and none could be resolved from the service provider. Either provide an {nameof(IChatClient)} explicitly or register one in the dependency injection container.");
+
+            return new StructuredOutputAgent(innerAgent, chatClient, optionsFactory?.Invoke());
+        });
+    }
+}

dotnet/samples/GettingStarted/Agents/Agent_Step05_StructuredOutput/StructuredOutputAgent.cs

@@ -0,0 +1,88 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI;
+using Microsoft.Extensions.AI;
+
+namespace SampleApp;
+
+/// <summary>
+/// A delegating AI agent that converts text responses from an inner AI agent into structured output using a chat client.
+/// </summary>
+/// <remarks>
+/// <para>
+/// The <see cref="StructuredOutputAgent"/> wraps an inner agent and uses a chat client to transform
+/// the inner agent's text response into a structured JSON format based on the specified response format.
+/// </para>
+/// <para>
+/// This agent requires a <see cref="ChatResponseFormatJson"/> to be specified either through the
+/// <see cref="AgentRunOptions.ResponseFormat"/> or the <see cref="StructuredOutputAgentOptions.ChatOptions"/>
+/// provided during construction.
+/// </para>
+/// </remarks>
+internal sealed class StructuredOutputAgent : DelegatingAIAgent
+{
+    private readonly IChatClient _chatClient;
+    private readonly StructuredOutputAgentOptions? _agentOptions;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="StructuredOutputAgent"/> class.
+    /// </summary>
+    /// <param name="innerAgent">The underlying agent that generates text responses to be converted to structured output.</param>
+    /// <param name="chatClient">The chat client used to transform text responses into structured JSON format.</param>
+    /// <param name="options">Optional configuration options for the structured output agent.</param>
+    public StructuredOutputAgent(AIAgent innerAgent, IChatClient chatClient, StructuredOutputAgentOptions? options = null)
+        : base(innerAgent)
+    {
+        this._chatClient = chatClient ?? throw new ArgumentNullException(nameof(chatClient));
+        this._agentOptions = options;
+    }
+
+    /// <inheritdoc />
+    protected override async Task<AgentResponse> RunCoreAsync(
+        IEnumerable<ChatMessage> messages,
+        AgentSession? session = null,
+        AgentRunOptions? options = null,
+        CancellationToken cancellationToken = default)
+    {
+        // Run the inner agent first, to get back the text response we want to convert.
+        var textResponse = await this.InnerAgent.RunAsync(messages, session, options, cancellationToken).ConfigureAwait(false);
+
+        // Invoke the chat client to transform the text output into structured data.
+        ChatResponse soResponse = await this._chatClient.GetResponseAsync(
+            messages: this.GetChatMessages(textResponse.Text),
+            options: this.GetChatOptions(options),
+            cancellationToken: cancellationToken).ConfigureAwait(false);
+
+        return new StructuredOutputAgentResponse(soResponse, textResponse);
+    }
+
+    private List<ChatMessage> GetChatMessages(string? textResponseText)
+    {
+        List<ChatMessage> chatMessages = [];
+
+        if (this._agentOptions?.ChatClientSystemMessage is not null)
+        {
+            chatMessages.Add(new ChatMessage(ChatRole.System, this._agentOptions.ChatClientSystemMessage));
+        }
+
+        chatMessages.Add(new ChatMessage(ChatRole.User, textResponseText));
+
+        return chatMessages;
+    }
+
+    private ChatOptions GetChatOptions(AgentRunOptions? options)
+    {
+        ChatResponseFormat responseFormat = options?.ResponseFormat
+            ?? this._agentOptions?.ChatOptions?.ResponseFormat
+            ?? throw new InvalidOperationException($"A response format of type '{nameof(ChatResponseFormatJson)}' must be specified, but none was specified.");
+
+        if (responseFormat is not ChatResponseFormatJson jsonResponseFormat)
+        {
+            throw new NotSupportedException($"A response format of type '{nameof(ChatResponseFormatJson)}' must be specified, but was '{responseFormat.GetType().Name}'.");
+        }
+
+        var chatOptions = this._agentOptions?.ChatOptions?.Clone() ?? new ChatOptions();
+        chatOptions.ResponseFormat = jsonResponseFormat;
+        return chatOptions;
+    }
+}

dotnet/samples/GettingStarted/Agents/Agent_Step05_StructuredOutput/StructuredOutputAgentOptions.cs

@@ -0,0 +1,31 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI;
+using Microsoft.Extensions.AI;
+
+namespace SampleApp;
+
+/// <summary>
+/// Represents configuration options for a <see cref="StructuredOutputAgent"/>.
+/// </summary>
+#pragma warning disable CA1812 // Instantiated via AIAgentBuilderExtensions.UseStructuredOutput optionsFactory parameter
+internal sealed class StructuredOutputAgentOptions
+#pragma warning restore CA1812
+{
+    /// <summary>
+    /// Gets or sets the system message to use when invoking the chat client for structured output conversion.
+    /// </summary>
+    public string? ChatClientSystemMessage { get; set; }
+
+    /// <summary>
+    /// Gets or sets the chat options to use for the structured output conversion by the chat client
+    /// used by the agent.
+    /// </summary>
+    /// <remarks>
+    /// This property is optional. The <see cref="ChatOptions.ResponseFormat"/> should be set to a
+    /// <see cref="ChatResponseFormatJson"/> instance to specify the expected JSON schema for the structured output.
+    /// Note that if <see cref="AgentRunOptions.ResponseFormat"/> is provided when running the agent,
+    /// it will take precedence and override the <see cref="ChatOptions.ResponseFormat"/> specified here.
+    /// </remarks>
+    public ChatOptions? ChatOptions { get; set; }
+}

dotnet/samples/GettingStarted/Agents/Agent_Step05_StructuredOutput/StructuredOutputAgentResponse.cs

@@ -0,0 +1,28 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI;
+using Microsoft.Extensions.AI;
+
+namespace SampleApp;
+
+/// <summary>
+/// Represents an agent response that contains structured output and
+/// the original agent response from which the structured output was generated.
+/// </summary>
+internal sealed class StructuredOutputAgentResponse : AgentResponse
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="StructuredOutputAgentResponse"/> class.
+    /// </summary>
+    /// <param name="chatResponse">The <see cref="ChatResponse"/> containing the structured output.</param>
+    /// <param name="agentResponse">The original <see cref="AgentResponse"/> from the inner agent.</param>
+    public StructuredOutputAgentResponse(ChatResponse chatResponse, AgentResponse agentResponse) : base(chatResponse)
+    {
+        this.OriginalResponse = agentResponse;
+    }
+
+    /// <summary>
+    /// Gets the original non-structured response from the inner agent used by chat client to produce the structured output.
+    /// </summary>
+    public AgentResponse OriginalResponse { get; }
+}