/// <summary>
/// Attempts to handle a service method.
/// </summary>
protected async Task <HttpResponseMessage?> TryHandleServiceMethodAsync <TRequest, TResponse>(HttpMethodMapping <TRequest, TResponse> mapping, HttpRequestMessage httpRequest, Func <TRequest, CancellationToken, Task <ServiceResult <TResponse> > > invokeMethodAsync, CancellationToken cancellationToken)
where TRequest : ServiceDto, new()
where TResponse : ServiceDto, new()
{
if (mapping == null)
{
throw new ArgumentNullException(nameof(mapping));
}
if (httpRequest == null)
{
throw new ArgumentNullException(nameof(httpRequest));
}
if (invokeMethodAsync == null)
{
throw new ArgumentNullException(nameof(invokeMethodAsync));
}
if (httpRequest.RequestUri == null)
{
throw new ArgumentException("RequestUri must be specified.", nameof(httpRequest));
}
if (httpRequest.Method != mapping.HttpMethod)
{
return(null);
}
var pathParameters = TryMatchHttpRoute(httpRequest.RequestUri, m_rootPath + mapping.Path);
if (pathParameters == null)
{
return(null);
}
var context = new ServiceHttpContext();
ServiceHttpContext.SetContext(httpRequest, context);
var aspectHttpResponse = await AdaptTask(RequestReceivedAsync(httpRequest, cancellationToken)).ConfigureAwait(true);
if (aspectHttpResponse != null)
{
return(aspectHttpResponse);
}
ServiceErrorDto?error = null;
object?requestBody = null;
if (mapping.RequestBodyType != null)
{
try
{
var serializer = GetHttpContentSerializer(mapping.RequestBodyType);
var requestResult = await AdaptTask(serializer.ReadHttpContentAsync(mapping.RequestBodyType, httpRequest.Content, cancellationToken)).ConfigureAwait(true);
if (requestResult.IsFailure)
{
error = requestResult.Error;
}
else
{
requestBody = requestResult.Value;
}
}
catch (Exception exception) when(ShouldCreateErrorFromException(exception))
{
// cancellation can cause the wrong exception
cancellationToken.ThrowIfCancellationRequested();
// error reading request body
error = CreateErrorFromException(exception);
}
}
TResponse?response = null;
if (error == null)
{
var request = mapping.CreateRequest(requestBody);
var uriParameters = new Dictionary <string, string?>(StringComparer.OrdinalIgnoreCase);
foreach (var queryParameter in ParseQueryString(httpRequest.RequestUri.Query))
{
uriParameters[queryParameter.Key] = queryParameter.Value[0];
}
foreach (var pathParameter in pathParameters)
{
uriParameters[pathParameter.Key] = pathParameter.Value;
}
request = mapping.SetUriParameters(request, uriParameters);
request = mapping.SetRequestHeaders(request, HttpServiceUtility.CreateDictionaryFromHeaders(httpRequest.Headers, httpRequest.Content?.Headers) !);
context.Request = request;
if (!m_skipRequestValidation && !request.Validate(out var requestErrorMessage))
{
error = ServiceErrors.CreateInvalidRequest(requestErrorMessage);
}
else
{
var methodResult = await invokeMethodAsync(request, cancellationToken).ConfigureAwait(true);
if (methodResult.IsFailure)
{
error = methodResult.Error;
}
else
{
response = methodResult.Value;
if (!m_skipResponseValidation && !response.Validate(out var responseErrorMessage))
{
error = ServiceErrors.CreateInvalidResponse(responseErrorMessage);
response = null;
}
}
}
context.Result = error != null?ServiceResult.Failure(error) : ServiceResult.Success <ServiceDto>(response !);
}
HttpResponseMessage httpResponse;
if (error == null)
{
var responseMappingGroups = mapping.ResponseMappings
.GroupBy(x => x.MatchesResponse(response !))
.Where(x => x.Key != false)
.OrderByDescending(x => x.Key)
.ToList();
if (responseMappingGroups.Count >= 1 && responseMappingGroups[0].Count() == 1)
{
var responseMapping = responseMappingGroups[0].Single();
httpResponse = new HttpResponseMessage(responseMapping.StatusCode);
var responseHeaders = mapping.GetResponseHeaders(response !);
var headersResult = HttpServiceUtility.TryAddNonContentHeaders(httpResponse.Headers, responseHeaders);
if (headersResult.IsFailure)
{
throw new InvalidOperationException(headersResult.Error !.Message);
}
if (responseMapping.ResponseBodyType != null)
{
var serializer = GetHttpContentSerializer(responseMapping.ResponseBodyType);
var mediaType = responseMapping.ResponseBodyContentType ?? responseHeaders?.GetContentType() ?? GetAcceptedMediaType(httpRequest, serializer);
httpResponse.Content = serializer.CreateHttpContent(responseMapping.GetResponseBody(response !) !, mediaType);
if (m_disableChunkedTransfer)
{
await httpResponse.Content.LoadIntoBufferAsync().ConfigureAwait(false);
}
}
}
else
{
throw new InvalidOperationException($"Found {responseMappingGroups.Sum(x => x.Count())} valid HTTP responses for {typeof(TResponse).Name}: {response}");
}
}
else
{
var statusCode = error.Code == null ? HttpStatusCode.InternalServerError :
(TryGetCustomHttpStatusCode(error.Code) ?? HttpServiceErrors.TryGetHttpStatusCode(error.Code) ?? HttpStatusCode.InternalServerError);
httpResponse = new HttpResponseMessage(statusCode);
if (statusCode != HttpStatusCode.NoContent && statusCode != HttpStatusCode.NotModified)
{
var mediaType = GetAcceptedMediaType(httpRequest, m_contentSerializer);
httpResponse.Content = m_contentSerializer.CreateHttpContent(error, mediaType);
if (m_disableChunkedTransfer)
{
await httpResponse.Content.LoadIntoBufferAsync().ConfigureAwait(false);
}
}
}
httpResponse.RequestMessage = httpRequest;
await AdaptTask(ResponseReadyAsync(httpResponse, cancellationToken)).ConfigureAwait(true);
return(httpResponse);
}
