# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr

#

# This file is part of CubicWeb.

#

# CubicWeb is free software: you can redistribute it and/or modify it under the

# terms of the GNU Lesser General Public License as published by the Free

# Software Foundation, either version 2.1 of the License, or (at your option)

# any later version.

#

# CubicWeb 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 Lesser General Public License for more

# details.

#

# You should have received a copy of the GNU Lesser General Public License along

# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.

"""schema definition related entities"""

__docformat__ = "restructuredtext en"

from logilab.common.decorators import cached

from yams.schema import role_name

from cubicweb import ValidationError

from cubicweb.schema import ERQLExpression, RRQLExpression

from cubicweb.entities import AnyEntity, fetch_config

class CWEType(AnyEntity):

    __regid__ = 'CWEType'

    fetch_attrs, cw_fetch_order = fetch_config(['name'])

    def dc_title(self):

        return u'%s (%s)' % (self.name, self._cw._(self.name))

    def dc_long_title(self):

        stereotypes = []

        _ = self._cw._

        if self.final:

            stereotypes.append(_('final'))

        if stereotypes:

            return u'%s <<%s>>' % (self.dc_title(), ', '.join(stereotypes))

        return self.dc_title()

class CWRType(AnyEntity):

    __regid__ = 'CWRType'

    fetch_attrs, cw_fetch_order = fetch_config(['name'])

    def dc_title(self):

        return u'%s (%s)' % (self.name, self._cw._(self.name))

    def dc_long_title(self):

        stereotypes = []

        _ = self._cw._

        if self.symmetric:

            stereotypes.append(_('symmetric'))

        if self.inlined:

            stereotypes.append(_('inlined'))

        if self.final:

            stereotypes.append(_('final'))

        if stereotypes:

            return u'%s <<%s>>' % (self.dc_title(), ', '.join(stereotypes))

        return self.dc_title()

    def check_inlined_allowed(self):

        """check inlining is possible, raise ValidationError if not possible

        """

        # don't use the persistent schema, we may miss cardinality changes

        # in the same transaction

        for rdef in self.reverse_relation_type:

            card = rdef.cardinality[0]

            if not card in '?1':

                qname = role_name('inlined', 'subject')

                rtype = self.name

                stype = rdef.stype

                otype = rdef.otype

                msg = self._cw._("can't set inlined=True, "

                                 "%(stype)s %(rtype)s %(otype)s "

                                 "has cardinality=%(card)s")

                raise ValidationError(self.eid, {qname: msg % locals()})

class CWRelation(AnyEntity):

    __regid__ = 'CWRelation'

    fetch_attrs = fetch_config(['cardinality'])[0]

    def dc_title(self):

        return u'%s %s %s' % (

            self.from_entity[0].name,

            self.relation_type[0].name,

            self.to_entity[0].name)

    def dc_long_title(self):

        card = self.cardinality

        scard, ocard = u'', u''

        if card[0] != '1':

            scard = '[%s]' % card[0]

        if card[1] != '1':

            ocard = '[%s]' % card[1]

        return u'%s %s%s%s %s' % (

            self.from_entity[0].name,

            scard, self.relation_type[0].name, ocard,

            self.to_entity[0].name)

    @property

    def rtype(self):

        return self.relation_type[0]

    @property

    def stype(self):

        return self.from_entity[0]

    @property

    def otype(self):

        return self.to_entity[0]

    def yams_schema(self):

        rschema = self._cw.vreg.schema.rschema(self.rtype.name)

        return rschema.rdefs[(self.stype.name, self.otype.name)]

class CWAttribute(CWRelation):

    __regid__ = 'CWAttribute'

    def dc_long_title(self):

        card = self.cardinality

        scard = u''

        if card[0] == '1':

            scard = '+'

        return u'%s %s%s %s' % (

            self.from_entity[0].name,

            scard, self.relation_type[0].name,

            self.to_entity[0].name)

class CWConstraint(AnyEntity):

    __regid__ = 'CWConstraint'

    fetch_attrs, cw_fetch_order = fetch_config(['value'])

    def dc_title(self):

        return '%s(%s)' % (self.cstrtype[0].name, self.value or u'')

    @property

    def type(self):

        return self.cstrtype[0].name

class RQLExpression(AnyEntity):

    __regid__ = 'RQLExpression'

    fetch_attrs, cw_fetch_order = fetch_config(['exprtype', 'mainvars', 'expression'])

    def dc_title(self):

        return self.expression or u''

    def dc_long_title(self):

        return '%s(%s)' % (self.exprtype, self.expression or u'')

    @property

    def expression_of(self):

        for rel in ('read_permission', 'add_permission', 'delete_permission',

                    'update_permission', 'condition'):

            values = getattr(self, 'reverse_%s' % rel)

            if values:

                return values[0]

    @cached

    def _rqlexpr(self):

        if self.exprtype == 'ERQLExpression':

            return ERQLExpression(self.expression, self.mainvars, self.eid)

        #if self.exprtype == 'RRQLExpression':

        return RRQLExpression(self.expression, self.mainvars, self.eid)

    def check_expression(self, *args, **kwargs):

        return self._rqlexpr().check(*args, **kwargs)