Add envelope receiver access code request feature

Introduced a feature to allow envelope receivers to request an
access code via email on the login page.

- Added `OnInitializedAsync` in `LoginReceiverPage.razor` to
  trigger access code requests using `AuthService`.
- Implemented `RequestEnvelopeReceiverAccessCodeAsync` in
  `AuthService.cs` to handle API calls for access code requests.
- Added a new endpoint in `AuthController` to process access
  code requests, including validation, history recording, and
  email dispatching.
- Registered `IEnvelopeMailService` and `AddDispatcher` in
  `Program.cs` to support email dispatch and database operations.
- Refactored `AuthController` constructor for readability and
  added necessary `using` directives.
- Improved logging and error handling for better traceability
  and robustness.

These changes ensure a seamless and secure process for envelope
receivers to request access codes, enhancing the user experience.

EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/LoginReceiverPage.razor

@@ -144,6 +144,14 @@
     bool IsLoading;
     EnvelopeLoginResult? LoginResult;
 
+    protected override async Task OnInitializedAsync()
+    {
+        if (string.IsNullOrWhiteSpace(EnvelopeKey))
+            return;
+
+        _ = await AuthService.RequestEnvelopeReceiverAccessCodeAsync(EnvelopeKey);
+    }
+
     async Task OnKeyDownAsync(Microsoft.AspNetCore.Components.Web.KeyboardEventArgs e)
     {
         if (e.Key == "Enter")

EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Services/AuthService.cs

@@ -33,6 +33,20 @@ public class AuthService(IHttpClientFactory httpClientFactory)
         return response.StatusCode == HttpStatusCode.OK;
     }
 
+    /// <summary>
+    /// Triggers access code e-mail request flow for the receiver login page.
+    /// Calls POST /api/Auth/envelope-receiver/{key}/request-access-code.
+    /// </summary>
+    public async Task<bool> RequestEnvelopeReceiverAccessCodeAsync(string envelopeKey, CancellationToken cancel = default)
+    {
+        using var http = CreateDefaultClient();
+        var response = await http.PostAsync(
+            $"/api/Auth/envelope-receiver/{Uri.EscapeDataString(envelopeKey)}/request-access-code",
+            null,
+            cancel);
+        return response.IsSuccessStatusCode;
+    }
+
     /// <summary>
     /// Submits the access code for the given envelope key.
     /// Calls POST /api/Auth/envelope-receiver/{key} with multipart/form-data.

EnvelopeGenerator.Server/EnvelopeGenerator.Server/Controllers/AuthController.cs

@@ -1,7 +1,10 @@
 using DigitalData.Auth.Claims;
+using EnvelopeGenerator.Application.Common.Interfaces.Services;
+using EnvelopeGenerator.Application.EnvelopeReceivers.Queries;
 using EnvelopeGenerator.Server.Controllers.Interfaces;
 using EnvelopeGenerator.Server.Models;
 using EnvelopeGenerator.Domain.Constants;
+using MediatR;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authentication.Cookies;
 using Microsoft.AspNetCore.Authorization;
@@ -15,7 +18,9 @@ namespace EnvelopeGenerator.Server.Controllers;
 /// </summary>
 [Route("api/[controller]")]
 [ApiController]
-public partial class AuthController(IOptions<AuthTokenKeys> authTokenKeyOptions, IAuthorizationService authService) : ControllerBase, IAuthController
+public partial class AuthController(
+    IOptions<AuthTokenKeys> authTokenKeyOptions,
+    IAuthorizationService authService) : ControllerBase, IAuthController
 {
     private readonly AuthTokenKeys authTokenKeys = authTokenKeyOptions.Value;
 
@@ -82,6 +87,64 @@ public partial class AuthController(IOptions<AuthTokenKeys> authTokenKeyOptions,
     [HttpGet("check/envelope/{envelopeKey}")]
     public IActionResult CheckEnvelopeReceiver([FromRoute] string envelopeKey) => Ok();
 
+    /// <summary>
+    /// Sends the receiver access code e-mail on the first envelope login-page visit.
+    /// The operation is idempotent: if the code was already requested, it returns 200 without re-sending.
+    /// </summary>
+    /// <param name="key">Envelope receiver key.</param>
+    /// <response code="200">Access code is already available or requested successfully.</response>
+    /// <response code="404">Envelope receiver key was not found.</response>
+    /// <response code="500">Access code could not be persisted or e-mail could not be sent.</response>
+    [AllowAnonymous]
+    [HttpPost("envelope-receiver/{key}/request-access-code")]
+    public async Task<IActionResult> RequestEnvelopeReceiverAccessCode(
+        [FromRoute] string key,
+        [FromServices] IMediator mediator,
+        [FromServices] IEnvelopeHistoryService historyService,
+        [FromServices] IEnvelopeMailService mailService,
+        [FromServices] ILogger<AuthController> logger,
+        CancellationToken cancel)
+    {
+        var envelopeReceiver = (await mediator.Send(new ReadEnvelopeReceiverQuery { Key = key }, cancel)).SingleOrDefault();
+
+        if (envelopeReceiver is null || envelopeReceiver.Envelope is null || envelopeReceiver.Receiver is null)
+            return NotFound();
+
+        if (envelopeReceiver.Envelope.UseAccessCode != true)
+            return Ok();
+
+        var userReference = envelopeReceiver.Receiver.EmailAddress;
+
+        if (await historyService.IsSigned(envelopeReceiver.EnvelopeId, userReference))
+            return Ok();
+
+        var accessCodeAlreadyRequested = await historyService.AccessCodeAlreadyRequested(envelopeReceiver.EnvelopeId, userReference);
+        if (accessCodeAlreadyRequested)
+            return Ok();
+
+        var historyResult = await historyService.RecordAsync(envelopeReceiver.EnvelopeId, userReference, EnvelopeStatus.AccessCodeRequested);
+        if (historyResult.IsFailed)
+        {
+            logger.LogWarning(
+                "Failed to record AccessCodeRequested history for envelope {EnvelopeId} and receiver {ReceiverEmail}.",
+                envelopeReceiver.EnvelopeId,
+                userReference);
+            return StatusCode(StatusCodes.Status500InternalServerError);
+        }
+
+        var mailResult = await mailService.SendAccessCodeAsync(envelopeReceiver);
+        if (mailResult.IsFailed)
+        {
+            logger.LogWarning(
+                "Failed to send access code mail for envelope {EnvelopeId} and receiver {ReceiverEmail}.",
+                envelopeReceiver.EnvelopeId,
+                userReference);
+            return StatusCode(StatusCodes.Status500InternalServerError);
+        }
+
+        return Ok();
+    }
+
     /// <summary>
     /// Removes the per-envelope receiver cookie for the given envelope key.
     /// </summary>
@@ -108,4 +171,4 @@ public partial class AuthController(IOptions<AuthTokenKeys> authTokenKeyOptions,
             Response.Cookies.Delete(cookieName);
         return Ok();
     }
-}
+}

EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs

@@ -25,6 +25,7 @@ using NLog.Web;
 using NLog;
 using DigitalData.Auth.Claims;
 using EnvelopeGenerator.Server;
+using DigitalData.EmailProfilerDispatcher;
 
 var logger = LogManager.Setup().LoadConfigurationFromAppSettings().GetCurrentClassLogger();
 logger.Info("EnvelopeGenerator.Server logging initialized!");
@@ -323,6 +324,8 @@ try
         .AddEnvelopeGeneratorServices(config);
 #pragma warning restore CS0618
 
+    builder.Services.AddDispatcher<EGDbContext>();
+
     // User Preferences (theme, dark mode, grid layouts — stored in TBDD_CACHE)
     // Registration handled by Infrastructure DependencyInjection (AddEnvelopeGeneratorInfrastructureServices)
 
@@ -346,6 +349,7 @@ try
     builder.Services.AddScoped<EnvelopeReceiverService>();
     builder.Services.AddScoped<SignatureService>();
     builder.Services.AddScoped<SignatureCacheService>();
+    builder.Services.AddScoped<EnvelopeGenerator.Application.Common.Interfaces.Services.IEnvelopeMailService, EnvelopeGenerator.Application.Services.EnvelopeMailService>();
     builder.Services.AddSingleton<AppVersionService>();
 
     // EnvelopeService with HttpClient factory (for SSR scenarios)