/// <summary>
/// Fetch file for created session.
/// </summary>
/// <param name="sessionId">Session identifier.</param>
/// <param name="templateCode">Element's template code.</param>
/// <param name="fetchParameters">Fetch parameters.</param>
/// <exception cref="InvalidTemplateException">Specified template code does not refer to binary element.</exception>
/// <exception cref="InvalidFetchUrlException">Fetch URL is invalid.</exception>
/// <exception cref="MissingFilenameException">Filename is not specified.</exception>
/// <exception cref="ObjectNotFoundException">Session or template has not been found.</exception>
/// <exception cref="SessionExpiredException">Specified session is expired.</exception>
/// <exception cref="S3Exception">Error making request to S3.</exception>
/// <exception cref="InvalidBinaryException">Binary does not meet template's constraints.</exception>
/// <exception cref="FetchFailedException">Fetch request failed.</exception>
/// <returns>Fetched file key.</returns>
public async Task <string> FetchFile(Guid sessionId, int templateCode, FetchParameters fetchParameters)
{
if (!TryCreateUri(fetchParameters, out var fetchUri))
{
throw new InvalidFetchUrlException(
$"Fetch URI must be a valid absolute URI with '{Uri.UriSchemeHttp}' or '{Uri.UriSchemeHttps}' scheme");
}
MultipartUploadSession uploadSession = null;
var(sessionDescriptor, _, expiresAt) = await _sessionStorageReader.GetSessionDescriptor(sessionId); // Firstly ensure that specified session exists
try
{
var(stream, mediaType) = await _fetchClient.FetchAsync(fetchUri);
var fileMetadata = new GenericUploadedFileMetadata(fetchParameters.FileName, mediaType, stream.Length);
uploadSession = await InitiateMultipartUploadInternal(sessionId, templateCode, fileMetadata, sessionDescriptor, expiresAt);
await UploadFilePart(uploadSession, stream, templateCode);
var fetchedFileKey = await CompleteMultipartUpload(uploadSession);
return(fetchedFileKey);
}
catch (FetchResponseTooLargeException ex)
{
throw new InvalidBinaryException(templateCode, new BinaryTooLargeError(ex.ContentLength));
}
catch (FetchRequestException ex)
{
throw new FetchFailedException($"Fetch request failed with status code {ex.StatusCode} and content: {ex.Message}");
}
catch (HttpRequestException ex)
{
throw new FetchFailedException($"Fetch request failed: {ex.Message}");
}
catch (TimeoutRejectedException)
{
throw new FetchFailedException("Fetch request failed: request timeout exceeded");
}
catch (FetchResponseContentTypeInvalidException ex)
{
throw new FetchFailedException($"Fetch request failed: {ex.Message}");
}
finally
{
if (uploadSession != null)
{
await AbortMultipartUpload(uploadSession);
}
}
}
private static bool TryParseUploadedFileMetadata(
IFormFile file,
string rawFileType,
string rawImageSize,
out IUploadedFileMetadata uploadedFileMetadata,
out string error)
{
uploadedFileMetadata = null;
error = null;
if (string.IsNullOrEmpty(rawFileType))
{
uploadedFileMetadata = new GenericUploadedFileMetadata(file.FileName, file.ContentType, file.Length);
return(true);
}
if (!Enum.TryParse <FileType>(rawFileType, true, out var fileType))
{
error = $"Cannot parse '{Http.HeaderNames.AmsFileType}' header value '{fileType}'";
return(false);
}
switch (fileType)
{
case FileType.SizeSpecificBitmapImage:
if (!ImageSize.TryParse(rawImageSize, out var imageSize))
{
error = $"Cannot parse '{Http.HeaderNames.AmsImageSize}' header value '{rawImageSize}'";
return(false);
}
uploadedFileMetadata = new UploadedImageMetadata(file.FileName, file.ContentType, file.Length, imageSize);
return(true);
default:
error = $"Unexpected '{Http.HeaderNames.AmsFileType}' header value '{fileType}'";
return(false);
}
}
