feat(client): add MessagingServiceClient and dependency injection extensions

Introduce the Email contract and MessagingServiceClient that send mail through the Application layer via MediatR, and add AddMessagingServiceClient overloads for delegate- and IConfiguration-based setup. Remove the empty client DI placeholders.

src/presentation/DigitalData.MessagingService.Client/DependencyInjection/DependencyInjectionExtensions.cs

@@ -1,10 +0,0 @@
-#if NET
-namespace DigitalData.MessagingService.Client.DependencyInjection;
-
-/// <summary>
-/// 
-/// </summary>
-public static class DependencyInjectionExtensions
-{
-}
-#endif

src/presentation/DigitalData.MessagingService.Client/DependencyInjection/MessagingServiceConfiguration.cs

@@ -1,10 +0,0 @@
-#if NET
-namespace DigitalData.MessagingService.Client.DependencyInjection;
-
-/// <summary>
-/// 
-/// </summary>
-public class MessagingServiceConfiguration
-{
-}
-#endif

src/presentation/DigitalData.MessagingService.Client/DependencyInjectionExtensions.cs

@@ -0,0 +1,50 @@
+#if NET
+using DigitalData.MessagingService.Application.DependencyInjection;
+using DigitalData.MessagingService.Publisher;
+using DigitalData.MessagingService.RabbitMQ;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace DigitalData.MessagingService.Client.DependencyInjection;
+
+/// <summary>
+/// 
+/// </summary>
+public static class DependencyInjectionExtensions
+{
+    private static IServiceCollection AddMessagingServiceClientDefaults(this IServiceCollection services, string luckyPennySoftLicenseKey)
+    {
+        services.AddMessagingServiceApplication(luckyPennySoftLicenseKey);
+        return services.AddTransient<MessagingServiceClient>();
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="services"></param>
+    /// <param name="luckyPennySoftLicenseKey"></param>
+    /// <param name="configureRabbitMqConnection"></param>
+    /// <returns></returns>
+    public static IServiceCollection AddMessagingServiceClient(this IServiceCollection services, string luckyPennySoftLicenseKey, Action<RabbitMqConnectionConfiguration> configureRabbitMqConnection)
+    {
+        services.AddMessagingServiceClientDefaults(luckyPennySoftLicenseKey);
+        services.AddMessagingServicePublisher(configureRabbitMqConnection);
+        return services;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="services"></param>
+    /// <param name="luckyPennySoftLicenseKey"></param>
+    /// <param name="configuration"></param>
+    /// <param name="rabbitMqConnectionSectionName"></param>
+    /// <returns></returns>
+    public static IServiceCollection AddMessagingServiceClient(this IServiceCollection services, string luckyPennySoftLicenseKey, IConfiguration configuration, string rabbitMqConnectionSectionName = RabbitMqConnectionConfiguration.SectionName)
+    {
+        services.AddMessagingServiceClientDefaults(luckyPennySoftLicenseKey);
+        services.AddMessagingServicePublisher(configuration, rabbitMqConnectionSectionName);
+        return services;
+    }
+}
+#endif

src/presentation/DigitalData.MessagingService.Client/Email.cs

@@ -0,0 +1,34 @@
+#if NET
+namespace DigitalData.MessagingService.Client;
+
+/// <summary>
+/// Represents an email to be sent via the messaging service.
+/// </summary>
+public record Email
+{
+    /// <summary>
+    /// Sender email address.
+    /// </summary>
+    public required string From { get; init; }
+
+    /// <summary>
+    /// Email subject.
+    /// </summary>
+    public required string Subject { get; init; }
+
+    /// <summary>
+    /// Email body (HTML or plain text).
+    /// </summary>
+    public required string Body { get; init; }
+
+    /// <summary>
+    /// Indicates whether <see cref="Body"/> is HTML.
+    /// </summary>
+    public required bool IsHtml { get; init; }
+
+    /// <summary>
+    /// Recipient email addresses.
+    /// </summary>
+    public required List<string> To { get; init; }
+}
+#endif

src/presentation/DigitalData.MessagingService.Client/MessagingServiceClient.cs

@@ -0,0 +1,34 @@
+#if NET
+using DigitalData.MessagingService.Application.EmailAccounts.Queries;
+using DigitalData.MessagingService.Application.EmailSending.Commands;
+using MediatR;
+
+namespace DigitalData.MessagingService.Client;
+
+/// <summary>
+/// 
+/// </summary>
+public class MessagingServiceClient(ISender sender)
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="email"></param>
+    /// <param name="cancellationToken"></param>
+    /// <returns></returns>
+    public async Task SendAsync(Email email, CancellationToken cancellationToken = default)
+    {
+        await sender.Send(new PublishEmailViaSmtpCommand()
+        {
+            Sender = new GetEmailAccountQuery()
+            {
+                Username = email.From
+            },
+            Recipients = email.To,
+            Subject = email.Subject,
+            Body = email.Body,
+            IsHtml = email.IsHtml
+        }, cancellationToken);
+    }
+}
+#endif