# 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
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#     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.

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#     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
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# 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/>.



"""Spam checker for Gstudio"""
import warnings

from django.utils.importlib import import_module
from django.core.exceptions import ImproperlyConfigured

from gstudio.settings import SPAM_CHECKER_BACKENDS


def get_spam_checker(backend_path):
    """Return the selected spam checker backend"""
    try:
        backend_module = import_module(backend_path)
        backend = getattr(backend_module, 'backend')
    except (ImportError, AttributeError):
        warnings.warn('%s backend cannot be imported' % backend_path,
                      RuntimeWarning)
        backend = None
    except ImproperlyConfigured, e:
        warnings.warn(str(e), RuntimeWarning)
        backend = None

    return backend


def check_is_spam(content, content_object, request,
                  backends=SPAM_CHECKER_BACKENDS):
    """Return True if the content is a spam, else False"""
    for backend_path in backends:
        spam_checker = get_spam_checker(backend_path)
        is_spam = spam_checker(content, content_object, request)
        if is_spam:
            return True

    return False