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

# Copyright(C) 2010  Christophe Benz, Romain Bignon
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


from weboob.tools.misc import iter_fields


__all__ = ['FieldNotFound', 'IBaseCap', 'NotAvailable', 'NotLoaded', 'CapBaseObject']


class FieldNotFound(Exception):
    def __init__(self, obj, field):
        Exception.__init__(self, u'Field "%s" not found for object %s' % (field, obj))


class NotAvailableMeta(type):
    def __str__(self):
        return unicode(self).decode('utf-8')

    def __unicode__(self):
        return u'Not available'

    def __nonzero__(self):
        return False


class NotAvailable(object):
    __metaclass__ = NotAvailableMeta


class NotLoadedMeta(type):
    def __str__(self):
        return unicode(self).decode('utf-8')

    def __unicode__(self):
        return u'Not loaded'

    def __nonzero__(self):
        return False


class NotLoaded(object):
    __metaclass__ = NotLoadedMeta


class IBaseCap(object):
    pass


class CapBaseObject(object):
    FIELDS = None

    def __init__(self, id, backend=None):
        self.id = id
        self.backend = backend

    def __iscomplete__(self):
        """
        Return True if the object is completed.

        It is usefull when the object is a field of an other object which is
        going to be filled.

        The default behavior is to iter on fields (with iter_fields) and if
        a field is NotLoaded, return False.
        """
        for key, value in self.iter_fields():
            if value is NotLoaded:
                return False
        return True

    def iter_fields(self):
        """
        Iterate on the FIELDS keys and values.

        Can be overloaded to iterate on other things.

        @return [iter(key,value)]  iterator on key, value
        """

        if self.FIELDS is None:
            for key, value in iter_fields(self):
                if key != 'backend':
                    yield key, value
        else:
            yield 'id', self.id
            for attrstr in self.FIELDS:
                yield attrstr, getattr(self, attrstr)