Access to GH components from script

Hi,

Just spent hours searching for a way to access Grasshopper's built in components in a C# plugin.

The situation is like this: I have a definition that's getting ridiculously complex and is getting more brittle as I add more features to it so I've set up a dev environment in Visual Studio.

My Hope is to re-engineer the complex definition by encapsulating some of the complexity in C# code and I was looking for the best approach to translate the definition.

My current thinking is that there is a one to one mapping between GH components as they exist in the node editor and either Grasshopper SDK or RhinoCommon libraries.

Is this correct?

For example I got stuck in the first component which creates a polygon by using the Polygon component, where can this class be found?

The closest I got was Rhino.Geometry.PolyLine or Rhino.Geometry.PolyCurve but they don't provide the same functionality as the GH Polygon component.

It looks like I'm not on the right track on this and moving to writing plugins will mean having to replicate lots of the functionality that's available in GH UI editor.

Cheer

Paul