Add ModelContextProtocol.Core package (#428)

src/ModelContextProtocol.Core/Client/McpClientPrompt.cs

@@ -0,0 +1,78 @@
+using ModelContextProtocol.Protocol;
+using System.Text.Json;
+
+namespace ModelContextProtocol.Client;
+
+/// <summary>
+/// Represents a named prompt that can be retrieved from an MCP server and invoked with arguments.
+/// </summary>
+/// <remarks>
+/// <para>
+/// This class provides a client-side wrapper around a prompt defined on an MCP server. It allows
+/// retrieving the prompt's content by sending a request to the server with optional arguments.
+/// Instances of this class are typically obtained by calling <see cref="McpClientExtensions.ListPromptsAsync"/>
+/// or <see cref="McpClientExtensions.EnumeratePromptsAsync"/>.
+/// </para>
+/// <para>
+/// Each prompt has a name and optionally a description, and it can be invoked with arguments
+/// to produce customized prompt content from the server.
+/// </para>
+/// </remarks>
+public sealed class McpClientPrompt
+{
+    private readonly IMcpClient _client;
+
+    internal McpClientPrompt(IMcpClient client, Prompt prompt)
+    {
+        _client = client;
+        ProtocolPrompt = prompt;
+    }
+
+    /// <summary>Gets the underlying protocol <see cref="Prompt"/> type for this instance.</summary>
+    /// <remarks>
+    /// <para>
+    /// This property provides direct access to the underlying protocol representation of the prompt,
+    /// which can be useful for advanced scenarios or when implementing custom MCP client extensions.
+    /// </para>
+    /// <para>
+    /// For most common use cases, you can use the more convenient <see cref="Name"/> and 
+    /// <see cref="Description"/> properties instead of accessing the <see cref="ProtocolPrompt"/> directly.
+    /// </para>
+    /// </remarks>
+    public Prompt ProtocolPrompt { get; }
+
+    /// <summary>Gets the name of the prompt.</summary>
+    public string Name => ProtocolPrompt.Name;
+
+    /// <summary>Gets a description of the prompt.</summary>
+    public string? Description => ProtocolPrompt.Description;
+
+    /// <summary>
+    /// Gets this prompt's content by sending a request to the server with optional arguments.
+    /// </summary>
+    /// <param name="arguments">Optional arguments to pass to the prompt. Keys are parameter names, and values are the argument values.</param>
+    /// <param name="serializerOptions">The serialization options governing argument serialization.</param>
+    /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
+    /// <returns>A <see cref="ValueTask"/> containing the prompt's result with content and messages.</returns>
+    /// <remarks>
+    /// <para>
+    /// This method sends a request to the MCP server to execute this prompt with the provided arguments.
+    /// The server will process the request and return a result containing messages or other content.
+    /// </para>
+    /// <para>
+    /// This is a convenience method that internally calls <see cref="McpClientExtensions.GetPromptAsync"/> 
+    /// with this prompt's name and arguments.
+    /// </para>
+    /// </remarks>
+    public async ValueTask<GetPromptResult> GetAsync(
+        IEnumerable<KeyValuePair<string, object?>>? arguments = null,
+        JsonSerializerOptions? serializerOptions = null,
+        CancellationToken cancellationToken = default)
+    {
+        IReadOnlyDictionary<string, object?>? argDict =
+            arguments as IReadOnlyDictionary<string, object?> ??
+            arguments?.ToDictionary();
+
+        return await _client.GetPromptAsync(ProtocolPrompt.Name, argDict, serializerOptions, cancellationToken: cancellationToken).ConfigureAwait(false);
+    }
+}