private async Task ConvertToHttpRequestMessage()

in src/WebJobs.Extensions.DurableTask/Listener/TaskHttpActivityShim.cs [107:161]
51 lines of code
10 McCabe index (conditional complexity)

        private async Task<HttpRequestMessage> ConvertToHttpRequestMessage(DurableHttpRequest durableHttpRequest)
        {
            string contentType = "";
            HttpRequestMessage requestMessage = new HttpRequestMessage(durableHttpRequest.Method, durableHttpRequest.Uri);
            if (durableHttpRequest.Headers != null)
            {
                foreach (KeyValuePair<string, StringValues> entry in durableHttpRequest.Headers)
                {
                    if (entry.Key.Equals("Content-Type", StringComparison.OrdinalIgnoreCase))
                    {
                        foreach (string value in entry.Value)
                        {
                            if (value.Contains("multipart"))
                            {
                                throw new FunctionFailedException("Multipart content is not supported with CallHttpAsync.");
                            }
                            else
                            {
                                contentType = value;
                            }
                        }
                    }
                    else
                    {
                        requestMessage.Headers.Add(entry.Key, (IEnumerable<string>)entry.Value);
                    }
                }
            }

            if (durableHttpRequest.Content != null)
            {
                if (contentType == "")
                {
                    contentType = "text/plain";
                }

                if (string.Equals(contentType, "application/x-www-form-urlencoded", StringComparison.OrdinalIgnoreCase))
                {
                    requestMessage.Content = new StringContent(durableHttpRequest.Content, Encoding.UTF8, contentType);
                }
                else
                {
                    requestMessage.Content = new StringContent(durableHttpRequest.Content);
                    requestMessage.Content.Headers.ContentType = new MediaTypeHeaderValue(contentType);
                }
            }

            if (durableHttpRequest.TokenSource != null)
            {
                string accessToken = await durableHttpRequest.TokenSource.GetTokenAsync();
                requestMessage.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
            }

            return requestMessage;
        }