"""General utility functions common to client and server.

  This module contains a collection of general purpose utility functions.
"""
import pythoncom
import win32api, win32con

def IIDToInterfaceName(iid):
	"""Converts an IID to a string interface name.  
	
	Used primarily for debugging purposes, this allows a cryptic IID to
	be converted to a useful string name.  This will firstly look for interfaces
	known (ie, registered) by pythoncom.  If not known, it will look in the
	registry for a registered interface.

	iid -- An IID object.

	Result -- Always a string - either an interface name, or '<Unregistered interface>'
	"""
	try:
		return pythoncom.ServerInterfaces[iid]
	except KeyError:
		try:
			try:
				return win32api.RegQueryValue(win32con.HKEY_CLASSES_ROOT, "Interface\\%s" % iid)
			except win32api.error:
				pass
		except ImportError:
			pass
		return str(iid)