EnvelopeGenerator/EnvelopeGenerator.Web/Controllers/DocumentController.cs

using DigitalData.Core.Exceptions;
using EnvelopeGenerator.Application.Common.Extensions;
using EnvelopeGenerator.Application.EnvelopeReceivers.Queries;
using EnvelopeGenerator.Domain.Constants;
using MediatR;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;

namespace EnvelopeGenerator.Web.Controllers;

[Authorize(Roles = Role.FullyAuth)]
[ApiController]
[Route("api/[controller]")]
public class DocumentController : ControllerBase
{
    private readonly IMediator _mediator;
        
    private readonly ILogger<DocumentController> _logger;

    public DocumentController(IMediator mediator, ILogger<DocumentController> logger)
    {
        _mediator = mediator;
        _logger = logger;
    }

    [HttpGet("{envelopeKey}")]
    public async Task<IActionResult> GetDocument([FromRoute] string envelopeKey, CancellationToken cancel)
    {
        var envRcv = await _mediator.ReadEnvelopeReceiverAsync(envelopeKey, cancel) ?? throw new NotFoundException("Envelope Receiver is not found.");

        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");
    }
}