"""The automatic entity form.

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

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

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

_ = unicode

from logilab.common.decorators import iclassmethod

from cubicweb import typed_eid

from cubicweb.web import stdmsgs, uicfg

from cubicweb.web import form, formwidgets as fwdgs

from cubicweb.web.formfields import guess_field

from cubicweb.web.views import forms, editforms

class AutomaticEntityForm(forms.EntityFieldsForm):

    """base automatic form to edit any entity.

    Designed to be fully generated from schema but highly configurable through:

    * rtags (rcategories, rfields, rwidgets, inlined, rpermissions)

    * various standard form parameters

    XXX s/rtags/uicfg/ ?

    You can also easily customise it by adding/removing fields in

    AutomaticEntityForm instances.

    """

    id = 'edition'

    cwtarget = 'eformframe'

    cssclass = 'entityForm'

    copy_nav_params = True

    form_buttons = [fwdgs.SubmitButton(),

                    fwdgs.Button(stdmsgs.BUTTON_APPLY, cwaction='apply'),

                    fwdgs.Button(stdmsgs.BUTTON_CANCEL, cwaction='cancel')]

    attrcategories = ('primary', 'secondary')

    # class attributes below are actually stored in the uicfg module since we

    # don't want them to be reloaded

    rcategories = uicfg.autoform_section

    rfields = uicfg.autoform_field

    rfields_kwargs = uicfg.autoform_field_kwargs

    rinlined = uicfg.autoform_is_inlined

    rpermissions_overrides = uicfg.autoform_permissions_overrides

    @classmethod

    def erelations_by_category(cls, entity, categories=None, permission=None,

                               rtags=None, strict=False):

        """return a list of (relation schema, target schemas, role) matching

        categories and permission

        `strict`:

          bool telling if having local role is enough (strict = False) or not

        """

        if categories is not None:

            if not isinstance(categories, (list, tuple, set, frozenset)):

                categories = (categories,)

            if not isinstance(categories, (set, frozenset)):

                categories = frozenset(categories)

        eschema  = entity.e_schema

        if rtags is None:

            rtags = cls.rcategories

        permsoverrides = cls.rpermissions_overrides

        if entity.has_eid():

            eid = entity.eid

        else:

            eid = None

            strict = False

        for rschema, targetschemas, role in eschema.relation_definitions(True):

            # check category first, potentially lower cost than checking

            # permission which may imply rql queries

            if categories is not None:

                targetschemas = [tschema for tschema in targetschemas

                                 if rtags.etype_get(eschema, rschema, role, tschema) in categories]

                if not targetschemas:

                    continue

            if permission is not None:

                # tag allowing to hijack the permission machinery when

                # permission is not verifiable until the entity is actually

                # created...

                if eid is None and '%s_on_new' % permission in permsoverrides.etype_get(eschema, rschema, role):

                    yield (rschema, targetschemas, role)

                    continue

                if rschema.is_final():

                    if not rschema.has_perm(entity.req, permission, eid):

                        continue

                elif role == 'subject':

                    if not ((not strict and rschema.has_local_role(permission)) or

                            rschema.has_perm(entity.req, permission, fromeid=eid)):

                        continue

                    # on relation with cardinality 1 or ?, we need delete perm as well

                    # if the relation is already set

                    if (permission == 'add'

                        and rschema.cardinality(eschema, targetschemas[0], role) in '1?'

                        and eid and entity.related(rschema.type, role)

                        and not rschema.has_perm(entity.req, 'delete', fromeid=eid,

                                                 toeid=entity.related(rschema.type, role)[0][0])):

                        continue

                elif role == 'object':

                    if not ((not strict and rschema.has_local_role(permission)) or

                            rschema.has_perm(entity.req, permission, toeid=eid)):

                        continue

                    # on relation with cardinality 1 or ?, we need delete perm as well

                    # if the relation is already set

                    if (permission == 'add'

                        and rschema.cardinality(targetschemas[0], eschema, role) in '1?'

                        and eid and entity.related(rschema.type, role)

                        and not rschema.has_perm(entity.req, 'delete', toeid=eid,

                                                 fromeid=entity.related(rschema.type, role)[0][0])):

                        continue

            yield (rschema, targetschemas, role)

    @classmethod

    def esrelations_by_category(cls, entity, categories=None, permission=None,

                                strict=False):

        """filter out result of relations_by_category(categories, permission) by

        removing final relations

        return a sorted list of (relation's label, relation'schema, role)

        """

        result = []

        for rschema, ttypes, role in cls.erelations_by_category(

            entity, categories, permission, strict=strict):

            if rschema.is_final():

                continue

            result.append((rschema.display_name(entity.req, role), rschema, role))

        return sorted(result)

    @iclassmethod

    def field_by_name(cls_or_self, name, role='subject', eschema=None):

        """return field with the given name and role. If field is not explicitly

        defined for the form but `eclass` is specified, guess_field will be

        called.

        """

        try:

            return super(AutomaticEntityForm, cls_or_self).field_by_name(name, role)

        except form.FieldNotFound:

            if eschema is None or not name in cls_or_self.schema:

                raise

            rschema = cls_or_self.schema.rschema(name)

            # XXX use a sample target type. Document this.

            tschemas = rschema.targets(eschema, role)

            fieldcls = cls_or_self.rfields.etype_get(eschema, rschema, role,

                                                     tschemas[0])

            kwargs = cls_or_self.rfields_kwargs.etype_get(eschema, rschema,

                                                          role, tschemas[0])

            if kwargs is None:

                kwargs = {}

            if fieldcls:

                if not isinstance(fieldcls, type):

                    return fieldcls # already and instance

                return fieldcls(name=name, role=role, eidparam=True, **kwargs)

            field = guess_field(eschema, rschema, role, eidparam=True, **kwargs)

            if field is None:

                raise

            return field

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

        super(AutomaticEntityForm, self).__init__(*args, **kwargs)

        entity = self.edited_entity

        if entity.has_eid():

            entity.complete()

        for rschema, role in self.editable_attributes():

            try:

                self.field_by_name(rschema.type, role)

                continue # explicitly specified

            except form.FieldNotFound:

                # has to be guessed

                try:

                    field = self.field_by_name(rschema.type, role,

                                               eschema=entity.e_schema)

                    self.fields.append(field)

                except form.FieldNotFound:

                    # meta attribute such as <attr>_format

                    continue

        self.maxrelitems = self.req.property_value('navigation.related-limit')

        self.force_display = bool(self.req.form.get('__force_display'))

    @property

    def related_limit(self):

        if self.force_display:

            return None

        return self.maxrelitems + 1

    def relations_by_category(self, categories=None, permission=None):

        """return a list of (relation schema, target schemas, role) matching

        given category(ies) and permission

        """

        return self.erelations_by_category(self.edited_entity, categories,

                                           permission)

    def inlined_relations(self):

        """return a list of (relation schema, target schemas, role) matching

        given category(ies) and permission

        """

        # we'll need an initialized varmaker if there are some inlined relation

        self.initialize_varmaker()

        return self.erelations_by_category(self.edited_entity, True, 'add',

                                           self.rinlined)

    def srelations_by_category(self, categories=None, permission=None,

                               strict=False):

        """filter out result of relations_by_category(categories, permission) by

        removing final relations

        return a sorted list of (relation's label, relation'schema, role)

        """

        return self.esrelations_by_category(self.edited_entity, categories,

                                           permission, strict=strict)

    def action(self):

        """return the form's action attribute. Default to validateform if not

        explicitly overriden.

        """

        try:

            return self._action

        except AttributeError:

            return self.build_url('validateform')

    def set_action(self, value):

        """override default action"""

        self._action = value

    action = property(action, set_action)

    def editable_attributes(self):

        """return a list of (relation schema, role) to edit for the entity"""

        return [(rschema, role) for rschema, _, role in self.relations_by_category(

                self.attrcategories, 'add') if rschema != 'eid']

    def relations_table(self):

        """yiels 3-tuples (rtype, target, related_list)

        where <related_list> itself a list of :

          - node_id (will be the entity element's DOM id)

          - appropriate javascript's togglePendingDelete() function call

          - status 'pendingdelete' or ''

          - oneline view of related entity

        """

        entity = self.edited_entity

        pending_deletes = self.req.get_pending_deletes(entity.eid)

        for label, rschema, role in self.srelations_by_category('generic', 'add',

                                                                strict=True):

            relatedrset = entity.related(rschema, role, limit=self.related_limit)

            if rschema.has_perm(self.req, 'delete'):

                toggleable_rel_link_func = editforms.toggleable_relation_link

            else:

                toggleable_rel_link_func = lambda x, y, z: u''

            related = []

            for row in xrange(relatedrset.rowcount):

                nodeid = editforms.relation_id(entity.eid, rschema, role,

                                               relatedrset[row][0])

                if nodeid in pending_deletes:

                    status = u'pendingDelete'

                    label = '+'

                else:

                    status = u''

                    label = 'x'

                dellink = toggleable_rel_link_func(entity.eid, nodeid, label)

                eview = self.view('oneline', relatedrset, row=row)

                related.append((nodeid, dellink, status, eview))

            yield (rschema, role, related)

    def restore_pending_inserts(self, cell=False):

        """used to restore edition page as it was before clicking on

        'search for <some entity type>'

        """

        eid = self.edited_entity.eid

        cell = cell and "div_insert_" or "tr"

        pending_inserts = set(self.req.get_pending_inserts(eid))

        for pendingid in pending_inserts:

            eidfrom, rtype, eidto = pendingid.split(':')

            if typed_eid(eidfrom) == eid: # subject

                label = display_name(self.req, rtype, 'subject')

                reid = eidto

            else:

                label = display_name(self.req, rtype, 'object')

                reid = eidfrom

            jscall = "javascript: cancelPendingInsert('%s', '%s', null, %s);" \

                     % (pendingid, cell, eid)

            rset = self.req.eid_rset(reid)

            eview = self.view('text', rset, row=0)

            # XXX find a clean way to handle baskets

            if rset.description[0][0] == 'Basket':

                eview = '%s (%s)' % (eview, display_name(self.req, 'Basket'))

            yield rtype, pendingid, jscall, label, reid, eview

    # should_* method extracted to allow overriding

    def should_inline_relation_form(self, rschema, targettype, role):

        """return true if the given relation with entity has role and a

        targettype target should be inlined

        """

    def should_display_inline_creation_form(self, rschema, existant, card):

        """return true if a creation form should be inlined

        by default true if there is no related entity and we need at least one

        """

        return not existant and card in '1+' or self.req.form.has_key('force_%s_display' % rschema)

    def display_inline_creation_form(self, w, rschema, targettype, role,

                                     i18nctx):

        entity = self.edited_entity

        w(self.view('inline-creation', None, etype=targettype,

                    peid=entity.eid, ptype=entity.e_schema,

                    rtype=rschema, role=role, i18nctx=i18nctx))

    def should_display_add_new_relation_link(self, rschema, existant, card):

        """return true if we should add a link to add a new creation form

        (through ajax call)

        by default true if there is no related entity or if the relation has

        multiple cardinality

        """

        return not existant or card in '+*'

    def should_hide_add_new_relation_link(self, rschema, card):

        """return true if once an inlined creation form is added, the 'add new'

        link should be hidden

        by default true if the relation has single cardinality

        """

        return card in '1?'

    @property

    def form_needs_multipart(self):

        """true if the form needs enctype=multipart/form-data"""

        if super(AutomaticEntityForm, self).form_needs_multipart:

            return True

        # take a look at inlined forms to check (recursively) if they

        # need multipart handling.

        # XXX: this is very suboptimal because inlined forms will be

        #      selected / instantiated twice : here and during form rendering.

        #      Potential solutions:

        #       -> use subforms for inlined forms to get easiser access

        #       -> use a simple onload js function to check if there is

        #          a input type=file in the form

        #       -> generate the <form> node when the content is rendered

        #          and we know the correct enctype (formrenderer's w attribute

        #          is not a StringIO)

        for rschema, targettypes, role in self.inlined_relations():

            # inlined forms don't handle multiple target types

            if len(targettypes) != 1:

                continue

            targettype = targettypes[0]

            if self.should_inline_relation_form(rschema, targettype, role):

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

                subform = self.vreg['forms'].select('edition', self.req, entity=entity)

                if subform.form_needs_multipart:

                    return True

        return False

def etype_relation_field(etype, rtype, role='subject'):

    eschema = AutomaticEntityForm.schema.eschema(etype)

    return AutomaticEntityForm.field_by_name(rtype, role, eschema)

## default form ui configuration ##############################################