# -*- coding: utf-8 -*-

# Copyright (c) 2002 - 2018 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the general part of the interface to version control
systems.

The general part of the VCS interface defines classes to implement common
dialogs. These are a dialog to enter command options, a dialog to display
some repository information and an abstract base class. The individual
interfaces (i.e. CVS) have to be subclasses of this base class.
"""

from __future__ import unicode_literals

from E5Gui.E5Application import e5App

######################################################################
## Below is the factory function to instantiate the appropriate
## vcs object depending on the project settings.
######################################################################


def factory(vcs):
    """
    Modul factory function to generate the right vcs object.
    
    @param vcs name of the VCS system to be used (string)
    @return the instantiated VCS object
    """
    pluginManager = e5App().getObject("PluginManager")
    if pluginManager is None:
        # that should not happen
        vc = None
    
    vc = pluginManager.getPluginObject("version_control", vcs,
                                       maybeActive=True)
    if vc is None:
        # try alternative vcs interfaces assuming, that there is a common
        # indicator for the alternatives
        found = False
        for indicator, vcsData in \
                pluginManager.getVcsSystemIndicators().items():
            for vcsSystem, vcsSystemDisplay in vcsData:
                if vcsSystem == vcs:
                    found = True
                    break
            
            if found:
                if len(vcsData) > 1:
                    for vcsSystem, vcsSystemDisplay in vcsData:
                        if vcsSystem != vcs:
                            vc = pluginManager.getPluginObject(
                                "version_control", vcsSystem, maybeActive=True)
                            if vc is not None:
                                break
                break
    return vc


VcsBasicHelperSingleton = None


def getBasicHelper(project):
    """
    Module function to get a reference to the basic project helper singleton.
    
    @param project reference to the project object (Project)
    @return reference to the basic VCS project helper singleton
        (VcsProjectHelper)
    """
    global VcsBasicHelperSingleton
    
    if VcsBasicHelperSingleton is None:
        from .ProjectHelper import VcsProjectHelper
        VcsBasicHelperSingleton = VcsProjectHelper(None, project)
    
    return VcsBasicHelperSingleton
