import os
import win32api
import win32con
from win32com.shell import shell, shellcon
import _winreg

class IconOverlayExtension(object):
    _com_interfaces_ = [shell.IID_IShellIconOverlayIdentifier]
    _public_methods_ = [
        "GetOverlayInfo", "GetPriority", "IsMemberOf"
        ]

    def GetOverlayInfo(self): 
        return ("", 0, 0) 

    def GetPriority(self):
        return 0

    def IsMemberOf(self, path, attrib):
        return S_FALSE

def make_icon_overlay(name, icon, state, clsid):
    """
    Make an icon overlay COM class.

    Used to create different COM server classes for highlighting the
    files with different source controlled states (eg: unchanged, 
    modified, ...).
    """
    classname = "%sOverlay" % name
    prog_id = "Mercurial.ShellExtension.%s" % classname
    desc = "Merucurial icon overlay shell extension for %s files" % name.lower()
    reg = [
        (_winreg.HKEY_LOCAL_MACHINE, r"Software\Microsoft\Windows\CurrentVersion\Explorer\ShellIconOverlayIdentifiers\%s" % name) ]
    cls = type(
            classname,
            (IconOverlayExtension, ),
            dict(_reg_clsid_=clsid, _reg_progid_=prog_id, _reg_desc_=desc, registry_keys=reg, icon=icon, state=state))

    _overlay_classes.append(cls)
    # We need to register the class as global, as pythoncom will
    # create an instance of it.
    globals()[classname] = cls

def RegisterServer(cls):
    try:
        key = "CLSID\\%s\\PythonCOMPath" % cls._reg_clsid_
        path = _winreg.QueryValue(_winreg.HKEY_CLASSES_ROOT, key)
        _winreg.SetValue(_winreg.HKEY_CLASSES_ROOT, key, _winreg.REG_SZ, "%s;%s" % (path, hg_path))
    except:
        pass
        
    # Add the appropriate shell extension registry keys
    for category, keyname in cls.registry_keys: 
        _winreg.SetValue(category, keyname, _winreg.REG_SZ, cls._reg_clsid_)

    print cls._reg_desc_, "registration complete."
    
def UnregisterServer(cls):
    for category, keyname in cls.registry_keys:
        try:
            _winreg.DeleteKey(category, keyname)
        except WindowsError, details:
            import errno
            if details.errno != errno.ENOENT:
                raise
    print cls._reg_desc_, "unregistration complete."
    
_overlay_classes = []
make_icon_overlay("Changed", "changed.ico", "MODIFIED", "{102C6A24-5F38-4186-B64A-237011809FAB}")

if __name__=='__main__':
    from win32com.server import register

    register.UseCommandLine(ChangedOverlay,
            finalize_register = lambda: RegisterServer(ChangedOverlay),
            finalize_unregister = lambda: UnregisterServer(ChangedOverlay))