# 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/>.

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

__docformat__ = "restructuredtext en"

from warnings import warn

from rql.utils import rqlvar_maker

from cubicweb import Binary, ValidationError, typed_eid

from cubicweb.view import EntityAdapter, implements_adapter_compat

from cubicweb.selectors import is_instance

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

                          ProcessFormError)

from cubicweb.web.views import basecontrollers, autoform

class IEditControlAdapter(EntityAdapter):

    __needs_bw_compat__ = True

    __regid__ = 'IEditControl'

    __select__ = is_instance('Any')

    @implements_adapter_compat('IEditControl')

    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(), {}

    @implements_adapter_compat('IEditControl')

    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 typed_eid(eid)

    except (ValueError, TypeError):

        return eid

class RqlQuery(object):

    def __init__(self):

        self.edited = []

        self.restrictions = []

        self.kwargs = {}

    def insert_query(self, etype):

        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):

        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

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 _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.set_shared_data('__maineid', form['__maineid'], txdata=True)

        # no specific action, generic edition

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

        self._pending_fields = req.data['pendingfields'] = set()

        try:

            for eid in req.edited_eids():

                # __type and eid

                formparams = req.extract_entity_params(eid, minparams=2)

                eid = self.edit_entity(formparams)

        except (RequestError, NothingToEdit), 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)})

        # handle relations in newly created entities

        if self._pending_fields:

            for form, field in self._pending_fields:

                self.handle_formfield(form, field)

        # execute rql to set all relations

        for querydef in self.relations_rql:

            self._cw.execute(*querydef)

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

        if req.form.has_key('__delete'):

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

            if todelete:

                autoform.delete_relations(self._cw, todelete)

        if req.form.has_key('__insert'):

            warn('[3.6] stop using __insert, support will be removed',

                 DeprecationWarning)

            toinsert = req.list_form_param('__insert', req.form, pop=True)

            if toinsert:

                autoform.insert_relations(self._cw, toinsert)

        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, ex:

            self._to_create[eid] = ex.entity

            if self._cw.json_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"""

        etype = formparams['__type']

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

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

        is_main_entity = self._cw.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 = self._cw.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 = self._cw.vreg['forms'].select(formid, self._cw, entity=entity)

        eid = form.actual_eid(entity.eid)

        try:

            editedfields = formparams['_cw_entity_fields']

        except KeyError:

            try:

                editedfields = formparams['_cw_edited_fields']

                warn('[3.13] _cw_edited_fields has been renamed _cw_entity_fields',

                     DeprecationWarning)

            except KeyError:

                raise RequestError(self._cw._('no edited fields specified for entity %s' % entity.eid))

        form.formvalues = {} # init fields value cache

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

            self.handle_formfield(form, field, rqlquery)

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

        elif rqlquery.edited: # edition of an existant entity

            self._update_entity(eid, rqlquery)

        if is_main_entity:

            self.notify_edited(entity)

        if formparams.has_key('__delete'):

            # XXX deprecate?

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

            autoform.delete_relations(self._cw, todelete)

        if formparams.has_key('__cloned_eid'):

            entity.copy_relations(typed_eid(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):

        eschema = form.edited_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.kwargs[field.name] = value

                    rqlquery.edited.append('X %s %%(%s)s' % (rschema, rschema))

                else:

                    if form.edited_entity.has_eid():

                        origvalues = set(entity.eid for entity in form.edited_entity.related(field.name, field.role, entities=True))

                    else:

                        origvalues = set()

                    if value is None or value == origvalues:

                        continue # not edited / not modified / to do later

                    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:

                        self._pending_fields.add( (form, field) )

        except ProcessFormError, exc:

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

    def handle_inlined_relation(self, form, field, values, origvalues, rqlquery):

        """handle edition for the (rschema, x) relation of the given entity

        """

        attr = field.name

        if values:

            rqlquery.kwargs[attr] = iter(values).next()

            rqlquery.edited.append('X %s %s' % (attr, attr.upper()))

            rqlquery.restrictions.append('%s eid %%(%s)s' % (attr.upper(), attr))

        elif form.edited_entity.has_eid():

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

    def handle_relation(self, form, field, values, origvalues):

        """handle edition for the (rschema, x) relation of the given entity

        """

        etype = form.edited_entity.e_schema

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

        if field.role == 'subject':

            desttype = rschema.objects(etype)[0]

            card = rschema.rdef(etype, desttype).cardinality[0]

            subjvar, objvar = 'X', 'Y'

        else:

            desttype = rschema.subjects(etype)[0]

            card = rschema.rdef(desttype, etype).cardinality[1]

            subjvar, objvar = 'Y', 'X'

        eid = form.edited_entity.eid

        if field.role == 'object' or not rschema.inlined or not values:

            # this is not an inlined relation or no values specified,

            # explicty remove relations

            rql = 'DELETE %s %s %s WHERE X eid %%(x)s, Y eid %%(y)s' % (

                subjvar, rschema, objvar)

            for reid in origvalues.difference(values):

                self.relations_rql.append((rql, {'x': eid, 'y': reid}))

        seteids = values.difference(origvalues)

        if seteids:

            rql = 'SET %s %s %s WHERE X eid %%(x)s, Y eid %%(y)s' % (

                subjvar, rschema, objvar)

            for reid in seteids:

                self.relations_rql.append((rql, {'x': eid, 'y': reid}))

    def delete_entities(self, eidtypes):

        """delete entities from the repository"""

        redirect_info = set()

        eidtypes = tuple(eidtypes)

        for eid, etype in eidtypes:

            entity = self._cw.entity_from_eid(eid, etype)

            path, params = entity.cw_adapt_to('IEditControl').after_deletion_path()

            redirect_info.add( (path, tuple(params.iteritems())) )

            entity.cw_delete()

        if len(redirect_info) > 1:

            # In the face of ambiguity, refuse the temptation to guess.

            self._after_deletion_path = 'view', ()

        else:

            self._after_deletion_path = iter(redirect_info).next()

        if len(eidtypes) > 1:

            self._cw.set_message(self._cw._('entities deleted'))

        else:

            self._cw.set_message(self._cw._('entity deleted'))

    def _action_apply(self):

        self._default_publish()

        self.reset()

    def _action_cancel(self):

        errorurl = self._cw.form.get('__errorurl')

        if errorurl:

            self._cw.cancel_edition(errorurl)

        self._cw.set_message(self._cw._('edit canceled'))

        return self.reset()

    def _action_delete(self):

        self.delete_entities(self._cw.edited_eids(withtype=True))

        return self.reset()