Added support for call to action responses

src/Tests/WhatsAppClientTests.cs

@@ -99,6 +99,39 @@ public async Task SendsButtonAsync()
         });
     }
 
+    [SecretsFact("Meta:VerifyToken", "SendFrom", "SendTo")]
+    public async Task SendsCallToActionAsync()
+    {
+        var (configuration, client) = Initialize();
+
+        // Send an interactive message with three buttons showcasing the payload/value 
+        // being different than the button text
+        await client.SendAsync(configuration["SendFrom"]!, new
+        {
+            messaging_product = "whatsapp",
+            recipient_type = "individual",
+            to = configuration["SendTo"]!,
+            type = "interactive",
+            interactive = new
+            {
+                type = "cta_url",
+                body = new
+                {
+                    text = "Tap the button to send a message to a contact"
+                },
+                action = new
+                {
+                    name = "cta_url",
+                    parameters = new
+                    {
+                        display_text = "Send",
+                        url = "https://wa.me/541234567890?text=Hi"
+                    }
+                }
+            }
+        });
+    }
+
     [SecretsFact("Meta:VerifyToken", "MediaTo", Skip = "Media attachments are deleted if user deletes them, so skip.")]
     public async Task ResolvesMediaIdFromHttpClient()
     {

src/WhatsApp/CallToActionResponse.cs

@@ -0,0 +1,22 @@
+namespace Devlooped.WhatsApp;
+
+/// <summary>
+/// Represents an interactive call to action that can be sent in response to a user message.
+/// </summary>
+/// <see cref="https://developers.facebook.com/docs/whatsapp/cloud-api/messages/interactive-cta-url-messages/"/>
+public record CallToActionResponse(string ServiceId, string UserNumber, string? Context, string Text, string ButtonText, string Url, string? ConversationId) : Response(ServiceId, UserNumber, Context, ConversationId)
+{
+    readonly CompositeService? service;
+
+    internal CallToActionResponse(Service service, string userNumber, string? context, string Text, string ButtonText, string Url, string? conversationId)
+        : this(service.Id, userNumber, context, Text, ButtonText, Url, conversationId)
+        => this.service = service as CompositeService;
+
+    protected override Task<string?> SendCoreAsync(IWhatsAppClient client, CancellationToken cancellation = default)
+    {
+        if (service != null)
+            return client.SendCallToActionAsync(service.Secondary.Id, UserNumber, Text, ButtonText, Url, cancellation);
+
+        return client.SendCallToActionAsync(ServiceId, UserNumber, Text, ButtonText, Url, cancellation);
+    }
+}

src/WhatsApp/IMessage.cs

@@ -21,6 +21,7 @@ namespace Devlooped.WhatsApp;
 [JsonDerivedType(typeof(TemplateResponse), "response/template")]
 [JsonDerivedType(typeof(ReactionResponse), "response/reaction")]
 [JsonDerivedType(typeof(TypingResponse), "response/typing")]
+[JsonDerivedType(typeof(CallToActionResponse), "response/cta")]
 public interface IMessage
 {
     /// <summary>Gets or sets any additional properties associated with the message.</summary>

src/WhatsApp/MessageExtensions.cs

@@ -109,6 +109,14 @@ public static TemplateResponse Template(this IMessage message, object template)
     public static TypingResponse Typing(this UserMessage message)
         => new(message.Service, message.User.Number, message.Id, message.ConversationId);
 
+    /// <summary>
+    /// Sends an interactive call to action response to the user message.
+    /// </summary>
+    public static CallToActionResponse CallToAction(this IMessage message, string text, string action, string url)
+        => message is UserMessage user
+        ? new(user.Service, message.UserNumber, message.Id, text, action, url, message.ConversationId)
+        : new(message.ServiceId, message.UserNumber, message.Id, text, action, url, message.ConversationId);
+
     /// <summary>
     /// Creates a text reply for the message.
     /// </summary>

src/WhatsApp/WhatsAppClientExtensions.cs

@@ -547,6 +547,42 @@ public static Task SendTyping(this IWhatsAppClient client, string serviceId, str
             }
         }, cancellation);
 
+    /// <summary>
+    /// Sends a call-to-action interactive message to a user.
+    /// </summary>
+    /// <param name="client">The WhatsApp client used to send the message.</param>
+    /// <param name="serviceId">The identifier for the service sending the message.</param>
+    /// <param name="userNumber">The phone number of the recipient. Must be in a valid format.</param>
+    /// <param name="message">The text message to be sent to the user.</param>
+    /// <param name="buttonText">The text displayed on the call-to-action button.</param>
+    /// <param name="cancellation">A token to monitor for cancellation requests. Defaults to <see cref="CancellationToken.None"/>.</param>
+    /// <returns>A task representing the asynchronous operation.</returns>
+    public static Task<string?> SendCallToActionAsync(this IWhatsAppClient client, string serviceId, string userNumber, string message, string buttonText, string url, CancellationToken cancellation = default)
+        => client.SendAsync(serviceId, new
+        {
+            messaging_product = "whatsapp",
+            recipient_type = "individual",
+            to = NormalizeNumber(userNumber),
+            type = "interactive",
+            interactive = new
+            {
+                type = "cta_url",
+                body = new
+                {
+                    text = message
+                },
+                action = new
+                {
+                    name = "cta_url",
+                    parameters = new
+                    {
+                        display_text = buttonText,
+                        url = url
+                    }
+                }
+            }
+        }, cancellation);
+
     static string NormalizeNumber(string number) =>
         // On the web, we don't get the 9 after 54 \o/
         // so for Argentina numbers, we need to remove the 9.