# Copyright (c) 2011,  2012 Free Software Foundation

#     This program is free software: you can redistribute it and/or modify
#     it under the terms of the GNU Affero General Public License as
#     published by the Free Software Foundation, either version 3 of the
#     License, or (at your option) any later version.

#     This program is distributed in the hope that it will be useful,
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#     GNU Affero General Public License for more details.

#     You should have received a copy of the GNU Affero General Public License
#     along with this program.  If not, see <http://www.gnu.org/licenses/>.


# This project incorporates work covered by the following copyright and permission notice:  

#    Copyright (c) 2009, Julien Fache
#    All rights reserved.

#    Redistribution and use in source and binary forms, with or without
#    modification, are permitted provided that the following conditions
#    are met:

#    * Redistributions of source code must retain the above copyright
#      notice, this list of conditions and the following disclaimer.
#    * Redistributions in binary form must reproduce the above copyright
#      notice, this list of conditions and the following disclaimer in
#      the documentation and/or other materials provided with the
#      distribution.
#    * Neither the name of the author nor the names of other
#      contributors may be used to endorse or promote products derived
#      from this software without specific prior written permission.

#    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
#    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
#    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
#    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
#    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
#    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
#    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
#    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
#    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
#    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
#    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

# Copyright (c) 2011,  2012 Free Software Foundation

#     This program is free software: you can redistribute it and/or modify
#     it under the terms of the GNU Affero General Public License as
#     published by the Free Software Foundation, either version 3 of the
#     License, or (at your option) any later version.

#     This program is distributed in the hope that it will be useful,
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#     GNU Affero General Public License for more details.

#     You should have received a copy of the GNU Affero General Public License
#     along with this program.  If not, see <http://www.gnu.org/licenses/>.


#    OF THE POSSIBILITY OF SUCH DAMAGE.
# coding: utf-8

class Registry(object):
    """
    Registry for application dashboards.
    """
    registry = {}
    
    def register(cls, klass, app_name):
        from grappelli.dashboard.dashboards import Dashboard
        if not issubclass(klass, Dashboard):
            raise ValueError('%s is not an instance of Dashboard' % klass)
        if app_name in cls.registry:
            raise ValueError('A dashboard has already been registered for '
                             'the application "%s"', app_name)
        cls.registry[app_name] = klass
    register = classmethod(register)


def register(cls, *args, **kwargs):
    """
    Register a custom dashboard into the global registry.
    """
    Registry.register(cls, *args, **kwargs)


def autodiscover(blacklist=[]):
    """
    Automagically discover custom dashboards and menus for installed apps.
    Optionally you can pass a ``blacklist`` of apps that you don't want to
    provide their own app index dashboard.
    """
    import imp
    from django.conf import settings
    from django.utils.importlib import import_module
    
    blacklist.append('grappelli')
    blacklist.append('grappelli.dashboard')
    
    for app in settings.INSTALLED_APPS:
        # skip blacklisted apps
        if app in blacklist:
            continue
        
        # try to import the app
        try:
            app_path = import_module(app).__path__
        except AttributeError:
            continue
        
        # try to find a app.dashboard module
        try:
            imp.find_module('dashboard', app_path)
        except ImportError:
            continue
        
        # looks like we found it so import it !
        import_module('%s.dashboard' % app)