"""some base form classes for CubicWeb web client

:organization: Logilab

:copyright: 2001-2010 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"

from warnings import warn

from logilab.common.decorators import iclassmethod

from logilab.common.compat import any

from logilab.common.deprecation import deprecated

from cubicweb import typed_eid

from cubicweb.selectors import non_final_entity, match_kwargs, one_line_rset

from cubicweb.web import INTERNAL_FIELD_VALUE, eid_param

from cubicweb.web import uicfg, form, formwidgets as fwdgs

from cubicweb.web.controller import NAV_FORM_PARAMETERS

from cubicweb.web.formfields import StringField, relvoc_unrelated, guess_field

class FieldsForm(form.Form):

    """base class for fields based forms.

    The following attributes may be either set on subclasses or given on

    form selection to customize the generated form:

    * `needs_js`: sequence of javascript files that should be added to handle

      this form (through `req.add_js`)

    * `needs_css`: sequence of css files that should be added to handle this

      form (through `req.add_css`)

    * `domid`: value for the "id" attribute of the <form> tag

    * `action`: value for the "action" attribute of the <form> tag

    * `onsubmit`: value for the "onsubmit" attribute of the <form> tag

    * `cssclass`: value for the "class" attribute of the <form> tag

    * `cssstyle`: value for the "style" attribute of the <form> tag

    * `cwtarget`: value for the "cubicweb:target" attribute of the <form> tag

    * `redirect_path`: relative to redirect to after submitting the form

    * `copy_nav_params`: flag telling if navigation paramenters should be copied

      back in hidden input

    * `form_buttons`:  form buttons sequence (button widgets instances)

    * `form_renderer_id`: id of the form renderer to use to render the form

    * `fieldsets_in_order`: fieldset name sequence, to control order

    """

    __regid__ = 'base'

    internal_fields = ('__errorurl',) + NAV_FORM_PARAMETERS

    # attributes overrideable by subclasses or through __init__

    needs_js = ('cubicweb.ajax.js', 'cubicweb.edition.js',)

    needs_css = ('cubicweb.form.css',)

    domid = 'form'

    action = None

    onsubmit = "return freezeFormButtons('%(domid)s');"

    cssclass = None

    cssstyle = None

    cwtarget = None

    redirect_path = None

    copy_nav_params = False

    form_buttons = None

    form_renderer_id = 'default'

    fieldsets_in_order = None

    def __init__(self, req, rset=None, row=None, col=None,

                 submitmsg=None, mainform=True,

                 **kwargs):

        super(FieldsForm, self).__init__(req, rset=rset, row=row, col=col)

        self.fields = list(self.__class__._fields_)

        for key, val in kwargs.items():

            if key in NAV_FORM_PARAMETERS:

                self.add_hidden(key, val)

            elif hasattr(self.__class__, key) and not key[0] == '_':

                setattr(self, key, val)

            else:

                self.cw_extra_kwargs[key] = val

            # skip other parameters, usually given for selection

            # (else write a custom class to handle them)

        if mainform:

            self.add_hidden('__errorurl', self.session_key())

            self.add_hidden('__domid', self.domid)

            self.restore_previous_post(self.session_key())

        # XXX why do we need two different variables (mainform and copy_nav_params ?)

        if self.copy_nav_params:

            for param in NAV_FORM_PARAMETERS:

                if not param in kwargs:

                    value = req.form.get(param)

                    if value:

                        self.add_hidden(param, value)

        if submitmsg is not None:

            self.add_hidden('__message', submitmsg)

        if 'domid' in kwargs:# session key changed

            self.restore_previous_post(self.session_key())

    @property

    def needs_multipart(self):

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

        return any(field.needs_multipart for field in self.fields)

    def add_hidden(self, name, value=None, **kwargs):

        """add an hidden field to the form"""

        kwargs.setdefault('widget', fwdgs.HiddenInput)

        field = StringField(name=name, value=value, **kwargs)

        if 'id' in kwargs:

            # by default, hidden input don't set id attribute. If one is

            # explicitly specified, ensure it will be set

            field.widget.setdomid = True

        self.append_field(field)

        return field

    def add_media(self):

        """adds media (CSS & JS) required by this widget"""

        if self.needs_js:

            self._cw.add_js(self.needs_js)

        if self.needs_css:

            self._cw.add_css(self.needs_css)

    def render(self, formvalues=None, rendervalues=None, renderer=None, **kwargs):

        """render this form, using the renderer given in args or the default

        FormRenderer()

        """

        if rendervalues is not None:

            warn('[3.6] rendervalues argument is deprecated, all named arguments will be given instead',

                 DeprecationWarning, stacklevel=2)

            kwargs = rendervalues

        self.build_context(formvalues)

        if renderer is None:

            renderer = self.default_renderer()

        return renderer.render(self, kwargs)

    def default_renderer(self):

        return self._cw.vreg['formrenderers'].select(

            self.form_renderer_id, self._cw,

            rset=self.cw_rset, row=self.cw_row, col=self.cw_col)

    formvalues = None

    def build_context(self, formvalues=None):

        """build form context values (the .context attribute which is a

        dictionary with field instance as key associated to a dictionary

        containing field 'name' (qualified), 'id', 'value' (for display, always

        a string).

        """

        if self.formvalues is not None:

            return # already built

        self.formvalues = formvalues or {}

        # use a copy in case fields are modified while context is build (eg

        # __linkto handling for instance)

        for field in self.fields[:]:

            for field in field.actual_fields(self):

                field.form_init(self)

    @deprecated('[3.6] use .add_hidden(name, value, **kwargs)')

    def form_add_hidden(self, name, value=None, **kwargs):

        return self.add_hidden(name, value, **kwargs)

    @deprecated('[3.6] use .render(formvalues, **rendervalues)')

    def form_render(self, **values):

        """render this form, using the renderer given in args or the default

        FormRenderer()

        """

        self.build_context(values)

        renderer = values.pop('renderer', None)

        if renderer is None:

            renderer = self.default_renderer()

        return renderer.render(self, values)

_AFF = uicfg.autoform_field

_AFF_KWARGS = uicfg.autoform_field_kwargs

class EntityFieldsForm(FieldsForm):

    __regid__ = 'base'

    __select__ = (match_kwargs('entity')

                  | (one_line_rset() & non_final_entity()))

    internal_fields = FieldsForm.internal_fields + ('__type', 'eid', '__maineid')

    domid = 'entityForm'

    @iclassmethod

    def field_by_name(cls_or_self, name, role=None, 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(EntityFieldsForm, cls_or_self).field_by_name(name, role)

        except form.FieldNotFound:

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

                raise

            rschema = eschema.schema.rschema(name)

            # XXX use a sample target type. Document this.

            tschemas = rschema.targets(eschema, role)

            fieldcls = _AFF.etype_get(eschema, rschema, role, tschemas[0])

            kwargs = _AFF_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, _cw, rset=None, row=None, col=None, **kwargs):

        try:

            self.edited_entity = kwargs.pop('entity')

        except KeyError:

            self.edited_entity = rset.complete_entity(row or 0, col or 0)

        msg = kwargs.pop('submitmsg', None)

        super(EntityFieldsForm, self).__init__(_cw, rset, row, col, **kwargs)

        self.add_hidden('__type', self.edited_entity.__regid__, eidparam=True)

        self.add_hidden('eid', self.edited_entity.eid)

        if kwargs.get('mainform', True): # mainform default to true in parent

            self.add_hidden(u'__maineid', self.edited_entity.eid)

            # If we need to directly attach the new object to another one

            if self._cw.list_form_param('__linkto'):

                for linkto in self._cw.list_form_param('__linkto'):

                    self.add_hidden('__linkto', linkto)

                if msg:

                    msg = '%s %s' % (msg, self._cw._('and linked'))

                else:

                    msg = self._cw._('entity linked')

        if msg:

            self.add_hidden('__message', msg)

    def session_key(self):

        """return the key that may be used to store / retreive data about a

        previous post which failed because of a validation error

        """

        if self.force_session_key is not None:

            return self.force_session_key

        # XXX if this is a json request, suppose we should redirect to the

        # entity primary view

        if self._cw.json_request and self.edited_entity.has_eid():

            return '%s#%s' % (self.edited_entity.absolute_url(), self.domid)

        return '%s#%s' % (self._cw.url(), self.domid)

    def build_context(self, formvalues=None):

        if self.formvalues is not None:

            return # already built

        super(EntityFieldsForm, self).build_context(formvalues)

        edited = set()

        for field in self.fields:

            if field.eidparam:

                edited.add(field.role_name())

        self.add_hidden('_cw_edited_fields', u','.join(edited),

                        eidparam=True)

    def default_renderer(self):

        return self._cw.vreg['formrenderers'].select(

            self.form_renderer_id, self._cw, rset=self.cw_rset, row=self.cw_row,

            col=self.cw_col, entity=self.edited_entity)

    # controller side method (eg POST reception handling)

    def actual_eid(self, eid):

        # should be either an int (existant entity) or a variable (to be

        # created entity)

        assert eid or eid == 0, repr(eid) # 0 is a valid eid

        try:

            return typed_eid(eid)

        except ValueError:

            try:

                return self._cw.data['eidmap'][eid]

            except KeyError:

                self._cw.data['eidmap'][eid] = None

                return None

    def editable_relations(self):

        return ()

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

        return False

    @deprecated('[3.6] use cw.web.formfields.relvoc_unrelated function')

    def subject_relation_vocabulary(self, rtype, limit=None):

        """defaut vocabulary method for the given relation, looking for

        relation's object entities (i.e. self is the subject)

        """

        return relvoc_unrelated(self.edited_entity, rtype, 'subject', limit=None)

    @deprecated('[3.6] use cw.web.formfields.relvoc_unrelated function')

    def object_relation_vocabulary(self, rtype, limit=None):

        return relvoc_unrelated(self.edited_entity, rtype, 'object', limit=None)

class CompositeFormMixIn(object):

    """form composed of sub-forms"""

    __regid__ = 'composite'

    form_renderer_id = __regid__

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

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

        self.forms = []

    def add_subform(self, subform):

        """mark given form as a subform and append it"""

        subform.parent_form = self

        self.forms.append(subform)

    def build_context(self, formvalues=None):

        super(CompositeFormMixIn, self).build_context(formvalues)

        for form in self.forms:

            form.build_context(formvalues)

class CompositeForm(CompositeFormMixIn, FieldsForm):

    pass

class CompositeEntityForm(CompositeFormMixIn, EntityFieldsForm):

    pass # XXX why is this class necessary?