Refactor document retrieval endpoints and authorization

- Updated DocumentController to use class-level [Authorize] and method-level role-based authorization for sender and receiver endpoints.
- Replaced ReadEnvelopeReceiverQuery with ReadDocumentQuery for sender document retrieval; simplified response logic.
- Added a new endpoint for fully authenticated receivers to fetch documents by envelope ID from user claims.
- Refactored ReadDocumentQuery and handler to always return DocumentDto, throw NotFoundException when needed, and use _repo.Query.
- Cleaned up using directives and removed legacy error handling and logging.

EnvelopeGenerator.API/Controllers/DocumentController.cs

@@ -1,6 +1,5 @@
-using DigitalData.Core.Exceptions;
-using EnvelopeGenerator.Application.Common.Extensions;
-using EnvelopeGenerator.Application.EnvelopeReceivers.Queries;
+using EnvelopeGenerator.API.Extensions;
+using EnvelopeGenerator.Application.Documents.Queries;
 using EnvelopeGenerator.Domain.Constants;
 using MediatR;
 using Microsoft.AspNetCore.Authorization;
@@ -14,7 +13,7 @@ namespace EnvelopeGenerator.API.Controllers;
 /// <remarks>
 /// Initializes a new instance of the <see cref="DocumentController"/> class.
 /// </remarks>
-[Authorize(Roles = Role.FullyAuth)]
+[Authorize]
 [ApiController]
 [Route("api/[controller]")]
 public class DocumentController(IMediator mediator, ILogger<DocumentController> logger) : ControllerBase
@@ -25,19 +24,28 @@ public class DocumentController(IMediator mediator, ILogger<DocumentController>
     /// <param name="query">Encoded envelope key.</param>
     /// <param name="cancel">Cancellation token.</param>
     [HttpGet]
-    public async Task<IActionResult> GetDocument(ReadEnvelopeReceiverQuery query, CancellationToken cancel)
+    [Authorize(Roles = Role.Sender)]
+    public async Task<IActionResult> GetDocument(ReadDocumentQuery query, CancellationToken cancel)
     {
-        var envRcv = await mediator.Send(query, cancel).FirstAsync(Exceptions.NotFound);
-
-        var byteData = envRcv.Envelope?.Documents?.FirstOrDefault()?.ByteData;
-
-        if (byteData is null || byteData.Length == 0)
-        {
-            logger.LogError("Document byte data is null or empty for envelope-receiver entity:\n{envelopeKey}.",
-                envRcv.ToJson(Format.Json.ForDiagnostics));
-            throw new NotFoundException("Document is empty.");
-        }
-
-        return File(byteData, "application/octet-stream");
+        var doc = await mediator.Send(query, cancel);
+        return doc.ByteData is byte[] docByte
+            ? File(docByte, "application/octet-stream")
+            : NotFound("Document is empty.");
     }
-}
+
+    /// <summary>
+    /// Returns the document bytes for the receiver.
+    /// </summary>
+    /// <param name="cancel">Cancellation token.</param>
+    [HttpGet]
+    [Authorize(Roles = Role.Receiver.FullyAuth)]
+    public async Task<IActionResult> GetDocument(CancellationToken cancel)
+    {
+        var envelopeId = User.GetEnvelopeIdOfReceiver();
+
+        var doc = await mediator.Send(new ReadDocumentQuery() { EnvelopeId = envelopeId }, cancel);
+        return doc.ByteData is byte[] docByte
+            ? File(docByte, "application/octet-stream")
+            : NotFound("Document is empty.");
+    }
+}