# copyright 2003-2013 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/>.

"""The edit controller, automatically handling entity form submitting"""

__docformat__ = "restructuredtext en"

from warnings import warn

from collections import defaultdict

from logilab.common.deprecation import deprecated

from logilab.common.graph import ordered_nodes

from rql.utils import rqlvar_maker

from cubicweb.view import EntityAdapter

from cubicweb.predicates import is_instance

from cubicweb.web import (INTERNAL_FIELD_VALUE, RequestError, NothingToEdit,

                          ProcessFormError)

from cubicweb.web.views import basecontrollers, autoform

class IEditControlAdapter(EntityAdapter):

    __regid__ = 'IEditControl'

    __select__ = is_instance('Any')

    def __init__(self, _cw, **kwargs):

        if self.__class__ is not IEditControlAdapter:

            warn('[3.14] IEditControlAdapter is deprecated, override EditController'

                 ' using match_edited_type or match_form_id selectors for example.',

                 DeprecationWarning)

        super(IEditControlAdapter, self).__init__(_cw, **kwargs)

    def after_deletion_path(self):

        """return (path, parameters) which should be used as redirect

        information when this entity is being deleted

        """

        parent = self.entity.cw_adapt_to('IBreadCrumbs').parent_entity()

        if parent is not None:

            return parent.rest_path(), {}

        return str(self.entity.e_schema).lower(), {}

    def pre_web_edit(self):

        """callback called by the web editcontroller when an entity will be

        created/modified, to let a chance to do some entity specific stuff.

        Do nothing by default.

        """

        pass

def valerror_eid(eid):

    try:

        return int(eid)

    except (ValueError, TypeError):

        return eid

class RqlQuery(object):

    def __init__(self):

        self.edited = []

        self.restrictions = []

        self.kwargs = {}

        self.canceled = False

    def __repr__(self):

        return ('Query <edited=%r restrictions=%r kwargs=%r>' % (

            self.edited, self.restrictions, self.kwargs))

    def insert_query(self, etype):

        assert not self.canceled

        if self.edited:

            rql = 'INSERT %s X: %s' % (etype, ','.join(self.edited))

        else:

            rql = 'INSERT %s X' % etype

        if self.restrictions:

            rql += ' WHERE %s' % ','.join(self.restrictions)

        return rql

    def update_query(self, eid):

        assert not self.canceled

        varmaker = rqlvar_maker()

        var = varmaker.next()

        while var in self.kwargs:

            var = varmaker.next()

        rql = 'SET %s WHERE X eid %%(%s)s' % (','.join(self.edited), var)

        if self.restrictions:

            rql += ', %s' % ','.join(self.restrictions)

        self.kwargs[var] = eid

        return rql

    def set_attribute(self, attr, value):

        self.kwargs[attr] = value

        self.edited.append('X %s %%(%s)s' % (attr, attr))

    def set_inlined(self, relation, value):

        self.kwargs[relation] = value

        self.edited.append('X %s %s' % (relation, relation.upper()))

        self.restrictions.append('%s eid %%(%s)s' % (relation.upper(), relation))

class EditController(basecontrollers.ViewController):

    __regid__ = 'edit'

    def publish(self, rset=None):

        """edit / create / copy / delete entity / relations"""

        for key in self._cw.form:

            # There should be 0 or 1 action

            if key.startswith('__action_'):

                cbname = key[1:]

                try:

                    callback = getattr(self, cbname)

                except AttributeError:

                    raise RequestError(self._cw._('invalid action %r' % key))

                else:

                    return callback()

        self._default_publish()

        self.reset()

    def _ordered_formparams(self):

        """ Return form parameters dictionaries for each edited entity.

        We ensure that entities can be created in this order accounting for

        mandatory inlined relations.

        """

        req = self._cw

        graph = {}

        get_rschema = self._cw.vreg.schema.rschema

        # minparams = 2, because at least __type and eid are needed

        values_by_eid = dict((eid, req.extract_entity_params(eid, minparams=2))

                             for eid in req.edited_eids())

        # iterate over all the edited entities

        for eid, values in values_by_eid.iteritems():

            # add eid to the dependency graph

            graph.setdefault(eid, set())

            # search entity's edited fields for mandatory inlined relation

            for param in values['_cw_entity_fields'].split(','):

                try:

                    rtype, role = param.split('-')

                except ValueError:

                    # e.g. param='__type'

                    continue

                rschema = get_rschema(rtype)

                if rschema.inlined:

                    for target in rschema.targets(values['__type'], role):

                        rdef = rschema.role_rdef(values['__type'], target, role)

                        # if cardinality is 1 and if the target entity is being

                        # simultaneously edited, the current entity must be

                        # created before the target one

                        if rdef.cardinality[0 if role == 'subject' else 1] == '1':

                            target_eid = values[param]

                            if target_eid in values_by_eid:

                                # add dependency from the target entity to the

                                # current one

                                if role == 'object':

                                    graph.setdefault(target_eid, set()).add(eid)

                                else:

                                    graph.setdefault(eid, set()).add(target_eid)

                                break

        for eid in reversed(ordered_nodes(graph)):

            yield values_by_eid[eid]

    def _default_publish(self):

        req = self._cw

        self.errors = []

        self.relations_rql = []

        form = req.form

        # so we're able to know the main entity from the repository side

        if '__maineid' in form:

            req.transaction_data['__maineid'] = form['__maineid']

        # no specific action, generic edition

        self._to_create = req.data['eidmap'] = {}

        # those two data variables are used to handle relation from/to entities

        # which doesn't exist at time where the entity is edited and that

        # deserves special treatment

        req.data['pending_inlined'] = defaultdict(set)

        req.data['pending_others'] = set()

        req.data['pending_composite_delete'] = set()

        try:

            for formparams in self._ordered_formparams():

                eid = self.edit_entity(formparams)

        except (RequestError, NothingToEdit) as ex:

            if '__linkto' in req.form and 'eid' in req.form:

                self.execute_linkto()

            elif not ('__delete' in req.form or '__insert' in req.form):

                raise ValidationError(None, {None: unicode(ex)})

        # all pending inlined relations to newly created entities have been

        # treated now (pop to ensure there are no attempt to add new ones)

        pending_inlined = req.data.pop('pending_inlined')

        assert not pending_inlined, pending_inlined

        # handle all other remaining relations now

        for form_, field in req.data.pop('pending_others'):

            self.handle_formfield(form_, field)

        # then execute rql to set all relations

        for querydef in self.relations_rql:

            self._cw.execute(*querydef)

        # delete pending composite

        for entity in req.data['pending_composite_delete']:

            entity.cw_delete()

        # XXX this processes *all* pending operations of *all* entities

        if '__delete' in req.form:

            todelete = req.list_form_param('__delete', req.form, pop=True)

            if todelete:

                autoform.delete_relations(self._cw, todelete)

        self._cw.remove_pending_operations()

        if self.errors:

            errors = dict((f.name, unicode(ex)) for f, ex in self.errors)

            raise ValidationError(valerror_eid(form.get('__maineid')), errors)

    def _insert_entity(self, etype, eid, rqlquery):

        rql = rqlquery.insert_query(etype)

        try:

            entity = self._cw.execute(rql, rqlquery.kwargs).get_entity(0, 0)

            neweid = entity.eid

        except ValidationError as ex:

            self._to_create[eid] = ex.entity

            if self._cw.ajax_request: # XXX (syt) why?

                ex.entity = eid

            raise

        self._to_create[eid] = neweid

        return neweid

    def _update_entity(self, eid, rqlquery):

        self._cw.execute(rqlquery.update_query(eid), rqlquery.kwargs)

    def edit_entity(self, formparams, multiple=False):

        """edit / create / copy an entity and return its eid"""

        req = self._cw

        etype = formparams['__type']

        entity = req.vreg['etypes'].etype_class(etype)(req)

        entity.eid = valerror_eid(formparams['eid'])

        is_main_entity = req.form.get('__maineid') == formparams['eid']

        # let a chance to do some entity specific stuff

        entity.cw_adapt_to('IEditControl').pre_web_edit()

        # create a rql query from parameters

        rqlquery = RqlQuery()

        # process inlined relations at the same time as attributes

        # this will generate less rql queries and might be useful in

        # a few dark corners

        if is_main_entity:

            formid = req.form.get('__form_id', 'edition')

        else:

            # XXX inlined forms formid should be saved in a different formparams entry

            # inbetween, use cubicweb standard formid for inlined forms

            formid = 'edition'

        form = req.vreg['forms'].select(formid, req, entity=entity)

        eid = form.actual_eid(entity.eid)

        editedfields = formparams['_cw_entity_fields']

        form.formvalues = {} # init fields value cache

        for field in form.iter_modified_fields(editedfields, entity):

            self.handle_formfield(form, field, rqlquery)

        # if there are some inlined field which were waiting for this entity's

        # creation, add relevant data to the rqlquery

        for form_, field in req.data['pending_inlined'].pop(entity.eid, ()):

            rqlquery.set_inlined(field.name, form_.edited_entity.eid)

        if not rqlquery.canceled:

            if self.errors:

                errors = dict((f.role_name(), unicode(ex)) for f, ex in self.errors)

                raise ValidationError(valerror_eid(entity.eid), errors)

            if eid is None: # creation or copy

                entity.eid = eid = self._insert_entity(etype, formparams['eid'], rqlquery)

            elif rqlquery.edited: # edition of an existant entity

                self._update_entity(eid, rqlquery)

        else:

            self.errors = []

        if is_main_entity:

            self.notify_edited(entity)

        if '__delete' in formparams:

            # XXX deprecate?

            todelete = req.list_form_param('__delete', formparams, pop=True)

            autoform.delete_relations(req, todelete)

        if '__cloned_eid' in formparams:

            entity.copy_relations(int(formparams['__cloned_eid']))

        if is_main_entity: # only execute linkto for the main entity

            self.execute_linkto(entity.eid)

        return eid

    def handle_formfield(self, form, field, rqlquery=None):

        entity = form.edited_entity

        eschema = entity.e_schema

        try:

            for field, value in field.process_posted(form):

                if not (

                    (field.role == 'subject' and field.name in eschema.subjrels)

                    or

                    (field.role == 'object' and field.name in eschema.objrels)):

                    continue

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

                if rschema.final:

                    rqlquery.set_attribute(field.name, value)

                    continue

                if entity.has_eid():

                    origvalues = set(data[0] for data in entity.related(field.name, field.role).rows)

                else:

                    origvalues = set()

                if value is None or value == origvalues:

                    continue # not edited / not modified / to do later

                unlinked_eids = origvalues - value

                if unlinked_eids:

                    # Special handling of composite relation removal

                    self.handle_composite_removal(

                        form, field, unlinked_eids, value, rqlquery)

                if rschema.inlined and rqlquery is not None and field.role == 'subject':

                    self.handle_inlined_relation(form, field, value, origvalues, rqlquery)

                elif form.edited_entity.has_eid():

                    self.handle_relation(form, field, value, origvalues)

                else:

                    form._cw.data['pending_others'].add( (form, field) )

        except ProcessFormError as exc:

            self.errors.append((field, exc))

    def handle_composite_removal(self, form, field,

                                 removed_values, new_values, rqlquery):

        """

        In EditController-handled forms, when the user removes a composite

        relation, it triggers the removal of the related entity in the

        composite. This is where this happens.

        See for instance test_subject_subentity_removal in

        web/test/unittest_application.py.

        """

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

        for unlinked_eid in removed_values:

            unlinked_entity = self._cw.entity_from_eid(unlinked_eid)

            rdef = rschema.role_rdef(form.edited_entity.cw_etype,

                                     unlinked_entity.cw_etype,

                                     field.role)

            if rdef.composite is not None:

                if rdef.composite == field.role:

                    to_be_removed = unlinked_entity

                else:

                    if unlinked_entity.cw_etype in new_value_etypes:

                        # This is a same-rdef re-parenting: do not remove the entity

                        continue

                    to_be_removed = form.edited_entity

                    self.info('Edition of %s is cancelled (deletion requested)',