#
#  Copyright (c) 2005 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
#

"""
Definition of the Concept class.

$Id$
"""

from zope.app import zapi
from zope.app.container.btree import BTreeContainer
from zope.app.container.contained import Contained
from zope.interface import implements
from persistent import Persistent

from cybertools.relation.interfaces import IRelationsRegistry
from cybertools.relation import DyadicRelation

from interfaces import IConcept
from interfaces import IConceptManager, IConceptManagerContained
from interfaces import ILoopsContained
from relations import ConceptRelation


class Concept(Contained, Persistent):

    implements(IConcept, IConceptManagerContained)

    _title = u''
    def getTitle(self): return self._title
    def setTitle(self, title): self._title = title
    title = property(getTitle, setTitle)

    def __init__(self, name=None, title=u''):
        self.title = title

    # concept relations:

    def getSubConcepts(self, relationships=None):
        rels = getRelations(first=self, relationships=relationships)
        return [r.second for r in rels]
        # TODO: sort...

    def getParentConcepts(self, relationships=None):
        rels = getRelations(second=self, relationships=relationships)
        return [r.first for r in rels]

    def assignConcept(self, concept, relationship=ConceptRelation):
        registry = zapi.getUtility(IRelationsRegistry)
        registry.register(relationship(self, concept))
        # TODO (?): avoid duplicates

    def deassignConcept(self, concept, relationships=None):
        pass  # TODO


class ConceptManager(BTreeContainer):

    implements(IConceptManager, ILoopsContained)


# TODO: move this to the cybertools.relation package

def getRelations(first=None, second=None, third=None, relationships=None):
    registry = zapi.getUtility(IRelationsRegistry)
    query = {}
    if first: query['first'] = first
    if second: query['second'] = second
    if third: query['third'] = third
    if not relationships:
        return registry.query(**query)
    else:
        result = []
        for r in relationships:
            query['relationship'] = r
            result.extend(registry.query(**query))
        return result