#
#  Copyright (c) 2007 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
#

"""
Common stuff.

$Id$
"""

from zope import component
from zope.component import adapts
from zope.interface import implements
from zope.cachedescriptors.property import Lazy
from zope.security.proxy import removeSecurityProxy
from persistent.mapping import PersistentMapping

from cybertools.typology.interfaces import IType
from loops.common import adapted, AdapterBase


# support for i18n content

class I18NValue(PersistentMapping):
    """ A dictionary to be used for storing values for different languages.
    """

    def lower(self):
        return str(self).lower()

    def __str__(self):
        return self.values()[0]


def getI18nValue(obj, attr, langInfo=None):
    obj = removeSecurityProxy(obj)
    value = getattr(obj, attr, None)
    lang = None
    if isinstance(value, I18NValue):
        lang = langInfo and langInfo.language or value.keys()[0]
        value = value.get(lang)
    #print '*** getI18nValue', attr, langInfo, lang, getattr(obj, attr, None), value
    return value

def setI18nValue(obj, attr, value, langInfo=None):
    obj = removeSecurityProxy(obj)
    old = getattr(obj, attr, None)
    if langInfo is None:
        setattr(obj, attr, value)
        return
    lang = langInfo.language
    if isinstance(old, I18NValue):
        old[lang] = value
    else:
        setattr(obj, attr, I18NValue(((lang, value),)))
    #print '*** setI18nValue', attr, langInfo, lang, value, getattr(obj, attr, None)


class I18NAdapterBase(AdapterBase):
    """ Base (or mix-in) class for concept adapters for internationalization of
        context attributes.
    """

    _adapterAttributes = AdapterBase._adapterAttributes + ('languageInfo',)
    languageInfo = None

    @Lazy
    def i18nAttributes(self):
        tp = IType(self.context)
        attrs = tp.optionsDict.get('i18nattributes', '')
        return [attr.strip() for attr in attrs.split(',')]

    def __getattr__(self, attr):
        self.checkAttr(attr)
        langInfo = attr in self.i18nAttributes and self.languageInfo or None
        return getI18nValue(self.context, '_' + attr, langInfo)

    def __setattr__(self, attr, value):
        if attr in self._adapterAttributes:
            object.__setattr__(self, attr, value)
        else:
            langInfo = attr in self.i18nAttributes and self.languageInfo or None
            self.checkAttr(attr)
            setI18nValue(self.context, '_' + attr, value, langInfo)