internal static DependencyTelemetry ExtractDependencyTelemetry()

in WEB/Src/DependencyCollector/DependencyCollector/TelemetryDiagnosticSourceListener.cs [78:194]
94 lines of code
18 McCabe index (conditional complexity)

        internal static DependencyTelemetry ExtractDependencyTelemetry(DiagnosticListener diagnosticListener, Activity currentActivity)
        {
            DependencyTelemetry telemetry = new DependencyTelemetry
            {
                Id = currentActivity.Id,
                Duration = currentActivity.Duration,
                Name = currentActivity.OperationName,
            };

            Uri requestUri = null;
            string component = null;
            string queryStatement = null;
            string httpUrl = null;
            string peerAddress = null;
            string peerService = null;

            foreach (KeyValuePair<string, string> tag in currentActivity.Tags)
            {
                // interpret Tags as defined by OpenTracing conventions
                // https://github.com/opentracing/specification/blob/master/semantic_conventions.md
                switch (tag.Key)
                {
                    case "component":
                        {
                            component = tag.Value;
                            break;
                        }

                    case "db.statement":
                        {
                            queryStatement = tag.Value;
                            break;
                        }

                    case "error":
                        {
                            if (bool.TryParse(tag.Value, out var failed))
                            {
                                telemetry.Success = !failed;
                                continue; // skip Properties
                            }

                            break;
                        }

                    case "http.status_code":
                        {
                            telemetry.ResultCode = tag.Value;
                            continue; // skip Properties
                        }

                    case "http.method":
                        {
                            continue; // skip Properties
                        }

                    case "http.url":
                        {
                            httpUrl = tag.Value;
                            if (Uri.TryCreate(tag.Value, UriKind.RelativeOrAbsolute, out requestUri))
                            {
                                continue; // skip Properties
                            }

                            break;
                        }

                    case "peer.address":
                        {
                            peerAddress = tag.Value;
                            break;
                        }

                    case "peer.hostname":
                        {
                            telemetry.Target = tag.Value;
                            continue; // skip Properties
                        }

                    case "peer.service":
                        {
                            peerService = tag.Value;
                            break;
                        }
                }

                // if more than one tag with the same name is specified, the first one wins
                // TODO verify if still needed once https://github.com/Microsoft/ApplicationInsights-dotnet/issues/562 is resolved 
                if (!telemetry.Properties.ContainsKey(tag.Key))
                {
                    telemetry.Properties.Add(tag);
                }
            }

            if (string.IsNullOrEmpty(telemetry.Type))
            {
                telemetry.Type = peerService ?? component ?? diagnosticListener.Name;
            }

            if (string.IsNullOrEmpty(telemetry.Target))
            {
                // 'peer.address' can be not user-friendly, thus use only if nothing else specified
                telemetry.Target = requestUri?.Host ?? peerAddress;
            }

            if (string.IsNullOrEmpty(telemetry.Name))
            {
                telemetry.Name = currentActivity.OperationName;
            }

            if (string.IsNullOrEmpty(telemetry.Data))
            {
                telemetry.Data = queryStatement ?? requestUri?.OriginalString ?? httpUrl;
            }

            return telemetry;
        }