# copyright 2003-2014 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/>.

"""

Renderers

---------

.. Note::

   Form renderers are responsible to layout a form to HTML.

Here are the base renderers available:

.. autoclass:: cubicweb.web.views.formrenderers.FormRenderer

.. autoclass:: cubicweb.web.views.formrenderers.HTableFormRenderer

.. autoclass:: cubicweb.web.views.formrenderers.EntityCompositeFormRenderer

.. autoclass:: cubicweb.web.views.formrenderers.EntityFormRenderer

.. autoclass:: cubicweb.web.views.formrenderers.EntityInlinedFormRenderer

"""

from cubicweb import _

from warnings import warn

from logilab.mtconverter import xml_escape

from logilab.common.registry import yes

from cubicweb import tags, uilib

from cubicweb.appobject import AppObject

from cubicweb.predicates import is_instance

from cubicweb.utils import json_dumps, support_args

from cubicweb.web import eid_param, formwidgets as fwdgs

def checkbox(name, value, attrs='', checked=None):

    if checked is None:

        checked = value

    checked = checked and 'checked="checked"' or ''

    return u'<input type="checkbox" name="%s" value="%s" %s %s />' % (

        name, value, checked, attrs)

def field_label(form, field):

    if callable(field.label):

        return field.label(form, field)

    # XXX with 3.6 we can now properly rely on 'if field.role is not None' and

    # stop having a tuple for label

    if isinstance(field.label, tuple): # i.e. needs contextual translation

        return form._cw.pgettext(*field.label)

    return form._cw._(field.label)

class FormRenderer(AppObject):

    """This is the 'default' renderer, displaying fields in a two columns table:

    +--------------+--------------+

    | field1 label | field1 input |

    +--------------+--------------+

    | field2 label | field2 input |

    +--------------+--------------+

    +---------+

    | buttons |

    +---------+

    """

    __registry__ = 'formrenderers'

    __regid__ = 'default'

    _options = ('display_label', 'display_help',

                'display_progress_div', 'table_class', 'button_bar_class',

                # add entity since it may be given to select the renderer

                'entity')

    display_label = True

    display_help = True

    display_progress_div = True

    table_class = u'attributeForm'

    button_bar_class = u'formButtonBar'

    def __init__(self, req=None, rset=None, row=None, col=None, **kwargs):

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

        if self._set_options(kwargs):

            raise ValueError('unconsumed arguments %s' % kwargs)

    def _set_options(self, kwargs):

        for key in self._options:

            try:

                setattr(self, key, kwargs.pop(key))

            except KeyError:

                continue

        return kwargs

    # renderer interface ######################################################

    def render(self, w, form, values):

        self._set_options(values)

        form.add_media()

        data = []

        _w = data.append

        _w(self.open_form(form, values))

        self.render_content(_w, form, values)

        _w(self.close_form(form, values))

        errormsg = self.error_message(form)

        if errormsg:

            data.insert(0, errormsg)

        # NOTE: we call unicode because `tag` objects may be found within data

        #       e.g. from the cwtags library

    def render_content(self, w, form, values):

        if self.display_progress_div:

            w(u'<div id="progress">%s</div>' % self._cw._('validating...'))

        w(u'\n<fieldset>\n')

        self.render_fields(w, form, values)

        self.render_buttons(w, form)

        w(u'\n</fieldset>\n')

    def render_label(self, form, field):

        if field.label is None:

            return u''

        label = field_label(form, field)

        attrs = {'for': field.dom_id(form)}

        if field.required:

            attrs['class'] = 'required'

        return tags.label(label, **attrs)

    def render_help(self, form, field):

        help = []

        descr = field.help

        if callable(descr):

            descr = descr(form, field)

        if descr:

            help.append('<div class="helper">%s</div>' % self._cw._(descr))

        example = field.example_format(self._cw)

        if example:

            help.append('<div class="helper">(%s: %s)</div>'

                        % (self._cw._('sample format'), example))

        return u' '.join(help)

    # specific methods (mostly to ease overriding) #############################

    def error_message(self, form):

        """return formatted error message

        This method should be called once inlined field errors has been consumed

        """

        req = self._cw

        errex = form.form_valerror

        # get extra errors

        if errex is not None:

            errormsg = req._('please correct the following errors:')

            errors = form.remaining_errors()

            if errors:

                if len(errors) > 1:

                    templstr = u'<li>%s</li>\n'

                else:

                    templstr = u' %s\n'

                for field, err in errors:

                    if not field:

                        errormsg += templstr % err

                    else:

                        errormsg += templstr % '%s: %s' % (req._(field), err)

                if len(errors) > 1:

                    errormsg = '<ul>%s</ul>' % errormsg

            return u'<div class="errorMessage">%s</div>' % errormsg

        return u''

    def open_form(self, form, values, **attrs):

        if form.needs_multipart:

            enctype = u'multipart/form-data'

        else:

            enctype = u'application/x-www-form-urlencoded'

        attrs.setdefault('enctype', enctype)

        attrs.setdefault('method', 'post')

        attrs.setdefault('action', form.form_action() or '#')

        if form.domid:

            attrs.setdefault('id', form.domid)

        if form.onsubmit:

            attrs.setdefault('onsubmit',  form.onsubmit)

        if form.cssstyle:

            attrs.setdefault('style', form.cssstyle)

        if form.cssclass:

            attrs.setdefault('class', form.cssclass)

        if form.cwtarget:

            attrs.setdefault('target', form.cwtarget)

        if not form.autocomplete:

            attrs.setdefault('autocomplete', 'off')

        return '<form %s>' % uilib.sgml_attributes(attrs)

    def close_form(self, form, values):

        """seems dumb but important for consistency w/ close form, and necessary

        for form renderers overriding open_form to use something else or more than

        and <form>

        """

        out = u'</form>'

        if form.cwtarget:

            attrs = {'name': form.cwtarget, 'id': form.cwtarget,

                     'width': '0px', 'height': '0px',

                     'src': 'javascript: void(0);'}

            out =  (u'<iframe %s></iframe>\n' % uilib.sgml_attributes(attrs)) + out

        return out

    def render_fields(self, w, form, values):

        fields = self._render_hidden_fields(w, form)

        if fields:

            self._render_fields(fields, w, form)

        self.render_child_forms(w, form, values)

    def render_child_forms(self, w, form, values):

        # render

        for childform in getattr(form, 'forms', []):

            self.render_fields(w, childform, values)

    def _render_hidden_fields(self, w, form):

        fields = form.fields[:]

        for field in form.fields:

            if not field.is_visible():

                w(field.render(form, self))

                w(u'\n')

                fields.remove(field)

        return fields

    def _render_fields(self, fields, w, form):

        byfieldset = {}

        for field in fields:

            byfieldset.setdefault(field.fieldset, []).append(field)

        if form.fieldsets_in_order:

            fieldsets = form.fieldsets_in_order

        else:

            fieldsets = byfieldset

        for fieldset in list(fieldsets):

            try:

                fields = byfieldset.pop(fieldset)

            except KeyError:

                self.warning('no such fieldset: %s (%s)', fieldset, form)

                continue

            w(u'<fieldset>\n')

            if fieldset:

                w(u'<legend>%s</legend>' % self._cw.__(fieldset))

            w(u'<table class="%s">\n' % self.table_class)

            for field in fields:

                w(u'<tr class="%s_%s_row">\n' % (field.name, field.role))

                if self.display_label and field.label is not None:

                    w(u'<th class="labelCol">%s</th>\n' % self.render_label(form, field))

                w(u'<td')

                if field.label is None:

                    w(u' colspan="2"')

                error = form.field_error(field)

                if error:

                    w(u' class="error"')

                w(u'>\n')

                w(field.render(form, self))

                w(u'\n')

                if error:

                    self.render_error(w, error)

                if self.display_help:

                    w(self.render_help(form, field))

                w(u'</td></tr>\n')

            w(u'</table></fieldset>\n')

        if byfieldset:

            self.warning('unused fieldsets: %s', ', '.join(byfieldset))

    def render_buttons(self, w, form):

        if not form.form_buttons:

            return

        w(u'<table class="%s">\n<tr>\n' % self.button_bar_class)

        for button in form.form_buttons:

            w(u'<td>%s</td>\n' % button.render(form))

        w(u'</tr></table>')

    def render_error(self, w, err):

        """return validation error for widget's field, if any"""

        w(u'<span class="errorMsg">%s</span>' % err)

class BaseFormRenderer(FormRenderer):

    """use form_renderer_id = 'base' if you want base FormRenderer layout even

    when selected for an entity

    """

    __regid__ = 'base'

class HTableFormRenderer(FormRenderer):

    """The 'htable' form renderer display fields horizontally in a table:

    +--------------+--------------+---------+

    | field1 label | field2 label |         |

    +--------------+--------------+---------+

    | field1 input | field2 input | buttons |

    +--------------+--------------+---------+

    """

    __regid__ = 'htable'

    display_help = False

    def _render_fields(self, fields, w, form):

        w(u'<table border="0" class="htableForm">')

        if self.display_label:

            w(u'<tr>')

            for field in fields:

                w(u'<th class="labelCol">%s</th>' % self.render_label(form, field))

                if self.display_help:

                    w(self.render_help(form, field))

            # empty slot for buttons

            w(u'<th class="labelCol">&#160;</th>')

            w(u'</tr>')

        w(u'<tr>')

        for field in fields:

            error = form.field_error(field)

            if error:

                w(u'<td class="error">')

                self.render_error(w, error)

            else:

                w(u'<td>')

            w(field.render(form, self))

            w(u'</td>')

        w(u'<td>')

        for button in form.form_buttons:

            w(button.render(form))

        w(u'</td>')

        w(u'</tr>')

        w(u'</table>')

    def render_buttons(self, w, form):

        pass

class OneRowTableFormRenderer(FormRenderer):

    """The 'htable' form renderer display fields horizontally in a table:

    +--------------+--------------+--------------+--------------+---------+

    | field1 label | field1 input | field2 label | field2 input | buttons |

    +--------------+--------------+--------------+--------------+---------+

    """

    __regid__ = 'onerowtable'

    display_help = False

    def _render_fields(self, fields, w, form):

        w(u'<table border="0" class="oneRowTableForm">')

        w(u'<tr>')

        for field in fields:

            if self.display_label:

                w(u'<th class="labelCol">%s</th>' % self.render_label(form, field))

            if self.display_help:

                w(self.render_help(form, field))

            error = form.field_error(field)

            if error:

                w(u'<td class="error">')

                self.render_error(w, error)

            else:

                w(u'<td>')

            w(field.render(form, self))

            w(u'</td>')

        w(u'<td>')

        for button in form.form_buttons:

            w(button.render(form))

        w(u'</td>')