"""widget classes for form construction

:organization: Logilab

:copyright: 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"

from datetime import date

from warnings import warn

from cubicweb import tags, uilib

from cubicweb.web import stdmsgs, INTERNAL_FIELD_VALUE, ProcessFormError

from logilab.mtconverter import xml_escape

class FieldWidget(object):

    """abstract widget class"""

    # javascript / css files required by the widget

    needs_js = ()

    needs_css = ()

    # automatically set id and tabindex attributes ?

    setdomid = True

    settabindex = True

    # does this widget expect a vocabulary

    vocabulary_widget = False

    def __init__(self, attrs=None, setdomid=None, settabindex=None):

        if attrs is None:

            attrs = {}

        self.attrs = attrs

        if setdomid is not None:

            # override class's default value

            self.setdomid = setdomid

        if settabindex is not None:

            # override class's default value

            self.settabindex = settabindex

    def add_media(self, form):

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

        if self.needs_js:

            form._cw.add_js(self.needs_js)

        if self.needs_css:

            form._cw.add_css(self.needs_css)

    def render(self, form, field, renderer):

        """render the widget for the given `field` of `form`.

        To override in concrete class

        """

        raise NotImplementedError

    def _render_attrs(self, form, field):

        """return html tag name, attributes and a list of values for the field

        """

        name = form.context[field]['name']

        values = form.context[field]['value']

        if not isinstance(values, (tuple, list)):

            values = (values,)

        attrs = dict(self.attrs)

        if self.setdomid:

            attrs['id'] = form.context[field]['id']

        if self.settabindex and not 'tabindex' in attrs:

            attrs['tabindex'] = form._cw.next_tabindex()

        return name, values, attrs

    def process_field_data(self, form, field):

        formkey = form.form_field_name(field)

        posted = form._cw.form

        return posted.get(formkey)

class Input(FieldWidget):

    """abstract widget class for <input> tag based widgets"""

    type = None

    def render(self, form, field, renderer):

        """render the widget for the given `field` of `form`.

        Generate one <input> tag for each field's value

        """

        self.add_media(form)

        name, values, attrs = self._render_attrs(form, field)

        # ensure something is rendered

        if not values:

            values = (INTERNAL_FIELD_VALUE,)

        inputs = [tags.input(name=name, value=value, type=self.type, **attrs)

                  for value in values]

        return u'\n'.join(inputs)

# basic html widgets ###########################################################

class TextInput(Input):

    """<input type='text'>"""

    type = 'text'

class PasswordInput(Input):

    """<input type='password'> and its confirmation field (using

    <field's name>-confirm as name)

    """

    type = 'password'

    def render(self, form, field, renderer):

        self.add_media(form)

        name, values, attrs = self._render_attrs(form, field)

        assert len(values) == 1

        id = attrs.pop('id')

        try:

            confirmname = '%s-confirm:%s' % tuple(name.rsplit(':', 1))

        except TypeError:

            confirmname = '%s-confirm' % name

        inputs = [tags.input(name=name, value=values[0], type=self.type, id=id,

                             **attrs),

                  '<br/>',

                  tags.input(name=confirmname, value=values[0], type=self.type,

                             **attrs),

                  ' ', tags.span(form._cw._('confirm password'),

                                      **{'class': 'emphasis'})]

        return u'\n'.join(inputs)

    def process_field_data(self, form, field):

        passwd1 = super(PasswordInput, self).process_field_data(form, field)

        fieldname = form.form_field_name(field)

        passwd2 = form._cw.form[fieldname+'-confirm']

        if passwd1 == passwd2:

            if passwd1 is None:

                return None

            return passwd1.encode('utf-8')

        raise ProcessFormError(form._cw._("password and confirmation don't match"))

class PasswordSingleInput(Input):

    """<input type='password'> without a confirmation field"""

    type = 'password'

    def process_field_data(self, form, field):

        value = super(PasswordSingleInput, self).process_field_data(form, field)

        if value is not None:

            return value.encode('utf-8')

        return value

class FileInput(Input):

    """<input type='file'>"""

    type = 'file'

    def _render_attrs(self, form, field):

        # ignore value which makes no sense here (XXX even on form validation error?)

        name, values, attrs = super(FileInput, self)._render_attrs(form, field)

        return name, ('',), attrs

class HiddenInput(Input):

    """<input type='hidden'>"""

    type = 'hidden'

    setdomid = False # by default, don't set id attribute on hidden input

    settabindex = False

class ButtonInput(Input):

    """<input type='button'>

    if you want a global form button, look at the Button, SubmitButton,

    ResetButton and ImgButton classes below.

    """

    type = 'button'

class TextArea(FieldWidget):

    """<textarea>"""

    def render(self, form, field, renderer):

        name, values, attrs = self._render_attrs(form, field)

        attrs.setdefault('onkeyup', 'autogrow(this)')

        if not values:

            value = u''

        elif len(values) == 1:

            value = values[0]

        else:

            raise ValueError('a textarea is not supposed to be multivalued')

        lines = value.splitlines()

        linecount = len(lines)

        for line in lines:

            linecount += len(line) / 80

        attrs.setdefault('cols', 80)

        attrs.setdefault('rows', min(15, linecount + 2))

        return tags.textarea(value, name=name, **attrs)

class FCKEditor(TextArea):

    """FCKEditor enabled <textarea>"""

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

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

        self.attrs['cubicweb:type'] = 'wysiwyg'

    def render(self, form, field, renderer):

        form._cw.fckeditor_config()

        return super(FCKEditor, self).render(form, field, renderer)

class Select(FieldWidget):

    """<select>, for field having a specific vocabulary"""

    vocabulary_widget = True

    def __init__(self, attrs=None, multiple=False):

        super(Select, self).__init__(attrs)

        self._multiple = multiple

    def render(self, form, field, renderer):

        name, curvalues, attrs = self._render_attrs(form, field)

        if not 'size' in attrs:

            attrs['size'] = self._multiple and '5' or '1'

        options = []

        optgroup_opened = False

        for option in field.vocabulary(form):

            try:

                label, value, oattrs = option

            except ValueError:

                label, value = option

                oattrs = {}

            if value is None:

                # handle separator

                if optgroup_opened:

                    options.append(u'</optgroup>')

                oattrs.setdefault('label', label or '')

                options.append(u'<optgroup %s>' % uilib.sgml_attributes(oattrs))

                optgroup_opened = True

            elif value in curvalues:

                options.append(tags.option(label, value=value,

                                           selected='selected', **oattrs))

            else:

                options.append(tags.option(label, value=value, **oattrs))

        if optgroup_opened:

            options.append(u'</optgroup>')

        return tags.select(name=name, multiple=self._multiple,

                           options=options, **attrs)

class CheckBox(Input):

    """<input type='checkbox'>, for field having a specific vocabulary. One

    input will be generated for each possible value.

    """

    type = 'checkbox'

    vocabulary_widget = True

    def render(self, form, field, renderer):

        name, curvalues, attrs = self._render_attrs(form, field)

        domid = attrs.pop('id', None)

        sep = attrs.pop('separator', u'<br/>\n')

        options = []

        for i, option in enumerate(field.vocabulary(form)):

            try:

                label, value, oattrs = option

            except ValueError:

                label, value = option

                oattrs = {}

            iattrs = attrs.copy()

            iattrs.update(oattrs)

            if i == 0 and domid is not None:

                iattrs.setdefault('id', domid)

            if value in curvalues:

                iattrs['checked'] = u'checked'

            tag = tags.input(name=name, type=self.type, value=value, **iattrs)

            options.append(tag + label)

        return sep.join(options)

class Radio(CheckBox):

    """<input type='radio'>, for field having a specific vocabulary. One

    input will be generated for each possible value.

    """

    type = 'radio'

# compound widgets #############################################################

class IntervalWidget(FieldWidget):

    """custom widget to display an interval composed by 2 fields. This widget

    is expected to be used with a CompoundField containing the two actual

    fields.

    Exemple usage::

from uicfg import autoform_field, autoform_section

autoform_field.tag_attribute(('Concert', 'minprice'),

                              CompoundField(fields=(IntField(name='minprice'),

                                                    IntField(name='maxprice')),

                                            label=_('price'),

                                            widget=IntervalWidget()

                                            ))

# we've to hide the other field manually for now

autoform_section.tag_attribute(('Concert', 'maxprice'), 'generated')

    """

    def render(self, form, field, renderer):

        actual_fields = field.fields

        assert len(actual_fields) == 2

        return u'<div>%s %s %s %s</div>' % (

            form._cw._('from_interval_start'),

            actual_fields[0].render(form, renderer),

            form._cw._('to_interval_end'),

            actual_fields[1].render(form, renderer),

            )

class HorizontalLayoutWidget(FieldWidget):

    """custom widget to display a set of fields grouped together horizontally

    in a form. See `IntervalWidget` for example usage.

    """

    def render(self, form, field, renderer):

        if self.attrs.get('display_label', True):

            subst = self.attrs.get('label_input_substitution', '%(label)s %(input)s')

            fields = [subst % {'label': renderer.render_label(form, f),

                              'input': f.render(form, renderer)}

                      for f in field.subfields(form)]

        else:

            fields = [f.render(form, renderer) for f in field.subfields(form)]

        return u'<div>%s</div>' % ' '.join(fields)

# javascript widgets ###########################################################

class DateTimePicker(TextInput):

    """<input type='text' + javascript date/time picker for date or datetime

    fields

    """

    monthnames = ('january', 'february', 'march', 'april',

                  'may', 'june', 'july', 'august',

                  'september', 'october', 'november', 'december')

    daynames = ('monday', 'tuesday', 'wednesday', 'thursday',

                'friday', 'saturday', 'sunday')

    needs_js = ('cubicweb.calendar.js',)

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

    @classmethod

    def add_localized_infos(cls, req):

        """inserts JS variables defining localized months and days"""

        # import here to avoid dependancy from cubicweb to simplejson

        _ = req._

        monthnames = [_(mname) for mname in cls.monthnames]

        daynames = [_(dname) for dname in cls.daynames]

        req.html_headers.define_var('MONTHNAMES', monthnames)

        req.html_headers.define_var('DAYNAMES', daynames)

    def render(self, form, field, renderer):

        txtwidget = super(DateTimePicker, self).render(form, field, renderer)

        self.add_localized_infos(form._cw)

        cal_button = self._render_calendar_popup(form, field)

        return txtwidget + cal_button

    def _render_calendar_popup(self, form, field):

        value = form.form_field_value(field)

        if not value:

            value = date.today()

        inputid = form.context[field]['id']

        helperid = '%shelper' % inputid

        year, month = value.year, value.month

        return (u"""<a onclick="toggleCalendar('%s', '%s', %s, %s);" class="calhelper">

<img src="%s" title="%s" alt="" /></a><div class="calpopup hidden" id="%s"></div>"""

                % (helperid, inputid, year, month,

                   form._cw.external_resource('CALENDAR_ICON'),

                   form._cw._('calendar'), helperid) )

# ajax widgets ################################################################

def init_ajax_attributes(attrs, wdgtype, loadtype=u'auto'):

    try:

        attrs['klass'] += u' widget'

    except KeyError:

        attrs['klass'] = u'widget'