public static bool TryParseOperation()

in edge-hub/core/src/Microsoft.Azure.Devices.Edge.Hub.Mqtt/TwinAddressHelper.cs [65:146]
71 lines of code
13 McCabe index (conditional complexity)

        public static bool TryParseOperation(string address, Dictionary<StringSegment, StringSegment> properties, out Operation operation, out StringSegment resource)
        {
            Preconditions.CheckArgument(CheckTwinAddress(address));

            int offset = ServicePrefix.Length;

            if ((address.Length > TwinPrefix.Length)
                && (string.CompareOrdinal(address, offset, TwinChannelSegment, 0, TwinChannelSegment.Length) == 0))
            {
                offset += TwinChannelSegment.Length;

                const string PatchReportedSegments = PatchMethod + SegmentSeparator + TwinNames.Properties + SegmentSeparator + TwinNames.Reported + SegmentSeparator;
                const string GetSegment = GetMethod + SegmentSeparator;

                if (string.CompareOrdinal(address, offset, PatchReportedSegments, 0, PatchReportedSegments.Length) == 0)
                {
                    operation = Operation.TwinPatchReportedState;
                    offset += PatchReportedSegments.Length;
                }
                else if (string.CompareOrdinal(address, offset, GetSegment, 0, GetSegment.Length) == 0)
                {
                    operation = Operation.TwinGetState;
                    offset += GetSegment.Length;
                }
                else
                {
                    operation = Operation.InvalidTwinRequest;
                    resource = default(StringSegment);
                    return false;
                }
            }
            else if ((address.Length > DirectMethodPrefix.Length)
                     && (string.CompareOrdinal(address, offset, DirectMethodResponseSegments, 0, DirectMethodResponseSegments.Length) == 0))
            {
                operation = Operation.DirectMethodResponse;
                offset += DirectMethodResponseSegments.Length;
            }
            else
            {
                operation = Operation.Unknown;
                resource = default(StringSegment);
                return false;
            }

            if (offset == address.Length)
            {
                resource = EmptyStringSegment;
                return true;
            }

            if (address[offset] == PropertiesSegmentPrefixChar) // check if property bag follows parsed part immediately
            {
                resource = EmptyStringSegment;
                offset++;
            }
            else
            {
                // find the final segment to derive
                int lastSegmentSeparatorIndex = address.LastIndexOf(SegmentSeparatorChar, address.Length - 1, address.Length - offset); // todo: check for off by 1
                if ((lastSegmentSeparatorIndex == -1) // no more segments
                    || (lastSegmentSeparatorIndex == address.Length - 1) // no more non-empty segments
                    || (address[lastSegmentSeparatorIndex + 1] != PropertiesSegmentPrefixChar)) // last segment is not a property bag
                {
                    // declare the rest of the address as resource
                    resource = StringSegmentAtOffset(address, offset);
                    return true;
                }
                else
                {
                    resource = StringSegmentRange(address, offset, lastSegmentSeparatorIndex - 1);
                    offset = lastSegmentSeparatorIndex + 2;
                }
            }

            // property bag follows last separator
            if (!TryParseProperties(address, offset, properties))
            {
                return false;
            }

            return true;
        }