feat: Add extension methods for simplyfying A2AClient usage (#152)

Co-authored-by: SergeyMenshykh <[email protected]>

Author: Blackhex

src/A2A/Client/A2AClientExtensions.cs

@@ -0,0 +1,132 @@
+using System.Net.ServerSentEvents;
+using System.Text.Json;
+
+namespace A2A;
+
+/// <summary>
+/// Extension methods for the <see cref="A2AClient"/> class making its API more
+/// convenient for certain use-cases.
+/// </summary>
+public static class A2AClientExtensions
+{
+    /// <inheritdoc cref="A2AClient.SendMessageAsync(MessageSendParams, CancellationToken)"/>
+    public static Task<A2AResponse> SendMessageAsync(
+        this A2AClient client,
+        Message message,
+        MessageSendConfiguration? configuration = null,
+        Dictionary<string, JsonElement>? metadata = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (client is null)
+        {
+            throw new ArgumentNullException(nameof(client));
+        }
+
+        return client.SendMessageAsync(
+            new MessageSendParams
+            {
+                Message = message,
+                Configuration = configuration,
+                Metadata = metadata
+            },
+            cancellationToken);
+    }
+
+    /// <inheritdoc cref="A2AClient.CancelTaskAsync(TaskIdParams, CancellationToken)"/>
+    public static Task<AgentTask> CancelTaskAsync(
+        this A2AClient client,
+        string taskId,
+        Dictionary<string, JsonElement>? metadata = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (client is null)
+        {
+            throw new ArgumentNullException(nameof(client));
+        }
+
+        return client.CancelTaskAsync(
+            new TaskIdParams
+            {
+                Id = taskId,
+                Metadata = metadata
+            },
+            cancellationToken);
+    }
+
+    /// <inheritdoc cref="A2AClient.SetPushNotificationAsync(TaskPushNotificationConfig, CancellationToken)"/>
+    public static Task<TaskPushNotificationConfig> SetPushNotificationAsync(
+        this A2AClient client,
+        string taskId,
+        string url,
+        string? configId = null,
+        string? token = null,
+        PushNotificationAuthenticationInfo? authentication = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (client is null)
+        {
+            throw new ArgumentNullException(nameof(client));
+        }
+
+        return client.SetPushNotificationAsync(
+            new TaskPushNotificationConfig
+            {
+                TaskId = taskId,
+                PushNotificationConfig = new PushNotificationConfig
+                {
+                    Id = configId,
+                    Url = url,
+                    Token = token,
+                    Authentication = authentication
+                }
+            },
+            cancellationToken);
+    }
+
+    /// <inheritdoc cref="A2AClient.GetPushNotificationAsync(GetTaskPushNotificationConfigParams, CancellationToken)"/>
+    public static Task<TaskPushNotificationConfig> GetPushNotificationAsync(
+        this A2AClient client,
+        string taskId,
+        string configId,
+        Dictionary<string, JsonElement>? metadata = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (client is null)
+        {
+            throw new ArgumentNullException(nameof(client));
+        }
+
+        return client.GetPushNotificationAsync(
+            new GetTaskPushNotificationConfigParams
+            {
+                Id = taskId,
+                PushNotificationConfigId = configId,
+                Metadata = metadata
+            },
+            cancellationToken);
+    }
+
+    /// <inheritdoc cref="A2AClient.SendMessageStreamingAsync(MessageSendParams, CancellationToken)"/>
+    public static IAsyncEnumerable<SseItem<A2AEvent>> SendMessageStreamingAsync(
+        this A2AClient client,
+        Message message,
+        MessageSendConfiguration? configuration = null,
+        Dictionary<string, JsonElement>? metadata = null,
+        CancellationToken cancellationToken = default)
+
+    {
+        if (client is null)
+        {
+            throw new ArgumentNullException(nameof(client));
+        }
+
+        return client.SendMessageStreamingAsync(
+            new MessageSendParams
+            {
+                Message = message,
+                Configuration = configuration,
+                Metadata = metadata
+            },
+            cancellationToken);
+    }
+}