#
#  Copyright (c) 2008 Helmut Merz helmutm@cy55.de
#
#  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; either version 2 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 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
#

"""
Export/import of annotations.

$Id$
"""

from datetime import datetime
import time
from zope.component import adapts
from zope.dublincore.interfaces import IZopeDublinCore
from zope.interface import implements

from loops.external.element import Element, elementTypes
from loops.external.interfaces import ISubExtractor
from loops.interfaces import ILoopsObject


class AnnotationsElement(Element):

    elementType = 'annotations'

    def __init__(self, **kw):
        for k, v in kw.items():
            self[k] = v

    def execute(self, loader):
        obj = self.parent.object
        dc = IZopeDublinCore(obj, None)
        if dc is not None:
            for k, v in self.items():
                if k in ('created', 'modified'):
                    v = datetime(*time.strptime(v, u'%Y-%m-%dT%H:%M')[0:6])
                setattr(dc, k, v)


class AnnotationsExtractor(object):

    implements(ISubExtractor)
    adapts(ILoopsObject)

    dcAttributes = ('title', 'description', 'creators', 'created', 'modified')

    def __init__(self, context):
        self.context = context

    def extract(self):
        dc = IZopeDublinCore(self.context, None)
        if dc is not None:
            result = {}
            for attr in self.dcAttributes:
                value = getattr(dc, attr, None)
                if attr in ('title',):
                    if value == getattr(self.context, attr):
                        value = None
                if value:
                    if attr in ('created', 'modified'):
                        value = value.strftime('%Y-%m-%dT%H:%M')
                    result[attr] = value
            if result:
                yield AnnotationsElement(**result)


elementTypes.update(dict(
    annotations=AnnotationsElement,
))