#!/usr/bin/python2.5

#

# Copyright 2009 the Melange authors.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#   http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""Custom widgets used for Survey form fields, plus the SurveyContent form.

"""

__authors__ = [

  '"Daniel Diniz" <ajaksu@gmail.com>',

  '"James Levy" <jamesalexanderlevy@gmail.com>',

  '"Lennard de Rijk" <ljvderijk@gmail.com>',

  ]

from itertools import chain

import datetime

from google.appengine.ext.db import djangoforms

from django import forms

from django.forms import widgets

from django.forms.fields import CharField

from django.template import loader

from django.utils.encoding import force_unicode

from django.utils.html import escape

from django.utils.safestring import mark_safe

from soc.logic import dicts

from soc.logic.lists import Lists

from soc.logic.models.survey import logic as survey_logic

from soc.logic.models.survey import results_logic

from soc.models.survey import SurveyContent

class SurveyForm(djangoforms.ModelForm):

  """Main SurveyContent form.

  This class is used to produce survey forms for several circumstances:

    - Admin creating survey from scratch

    - Admin updating existing survey

    - User taking survey

    - User updating already taken survey

  Using dynamic properties of the survey model (if passed as an arg) the

  survey form is dynamically formed.

  """

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

    """Store special kwargs as attributes.

      read_only: controls whether the survey taking UI allows data entry.

      editing: controls whether to show the edit or show form.

    """

    self.kwargs = kwargs

    self.survey_content = self.kwargs.get('survey_content', None)

    self.this_user = self.kwargs.get('this_user', None)

    self.project = self.kwargs.get('project', None)

    self.survey_record = self.kwargs.get('survey_record', None)

    del self.kwargs['survey_content']

    del self.kwargs['this_user']

    del self.kwargs['project']

    del self.kwargs['survey_record']

    self.read_only = self.kwargs.get('read_only', None)

    if 'read_only' in self.kwargs:

      del self.kwargs['read_only']

    self.editing = self.kwargs.get('editing', None)

    if 'editing' in self.kwargs:

      del self.kwargs['editing']

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

  def getFields(self):

    """Build the SurveyContent (questions) form fields.

    Populates self.survey_fields, which will be ordered in self.insert_fields.

    """

    if not self.survey_content:

      return

    self.survey_fields = {}

    schema = eval(self.survey_content.schema)

    has_record = (not self.editing) and self.survey_record

    extra_attrs = {}

    # figure out whether we want a read-only view

    if not self.editing:

      # only survey taking can be read-only

      read_only = self.read_only

      if not read_only:

        deadline = self.survey_content.survey_parent.get().deadline

        read_only =  deadline and (datetime.datetime.now() > deadline)

      else:

        extra_attrs['disabled'] = 'disabled'

    # add unordered fields to self.survey_fields

    for field in self.survey_content.dynamic_properties():

      # a comment made by the user

      comment = ''

      if has_record and hasattr(self.survey_record, field):

        # previously entered value

        value = getattr(self.survey_record, field)

        if hasattr(self.survey_record, 'comment_for_' + field):

          comment = getattr(self.survey_record, 'comment_for_' + field)

      else:

        # use prompts set by survey creator

        value = getattr(self.survey_content, field)

      if field not in schema:

        logging.error('field %s not found in schema %s' %

        (field, str(schema) ) )

        continue 

      elif 'question' in schema[field]:

        label = schema[field].get('question', None) or field

      else:

        label = field

      # dispatch to field-specific methods

      if schema[field]["type"] == "long_answer":

        self.addLongField(field, value, extra_attrs, label=label,

                          comment=comment)

      elif schema[field]["type"] == "short_answer":

        self.addShortField(field, value, extra_attrs, label=label,

                           comment=comment)

      elif schema[field]["type"] == "selection":

        self.addSingleField(field, value, extra_attrs, schema, label=label,

                            comment=comment)

      elif schema[field]["type"] == "pick_multi":

        self.addMultiField(field, value, extra_attrs, schema, label=label,

                           comment=comment)

      elif schema[field]["type"] == "pick_quant":

        self.addQuantField(field, value, extra_attrs, schema, label=label,

                           comment=comment)

    return self.insertFields()

  def insertFields(self):

    """Add ordered fields to self.fields.

    """

    survey_order = self.survey_content.getSurveyOrder()

    # first, insert dynamic survey fields

    for position, property in survey_order.items():

      position = position * 2

      self.fields.insert(position, property, self.survey_fields[property])

      if not self.editing:

        property = 'comment_for_' + property

        self.fields.insert(position - 1, property,

                           self.survey_fields[property])

    return self.fields

  def addLongField(self, field, value, attrs, req=False, label='', tip='',

                   comment=''):

    """Add a long answer fields to this form.

    params:

      field: the current field

      value: the initial value for this field

      attrs: additional attributes for field

      req: required bool

      label: label for field

      tip: tooltip text for field

      comment: initial comment value for field 

    """

    widget = widgets.Textarea(attrs=attrs)

    if not tip:

      tip = 'Please provide a long answer to this question.'

    question = CharField(help_text=tip, required=req, label=label,

                         widget=widget, initial=value)

    self.survey_fields[field] = question

    if not self.editing:

      widget = widgets.Textarea(attrs=attrs)

      comment = CharField(help_text=tip, required=False, label='Comments',

                          widget=widget, initial=comment)

      self.survey_fields['comment_for_' + field] = comment

  def addShortField(self, field, value, attrs, req=False, label='', tip='',

                    comment=''):

    """Add a short answer fields to this form.

    params:

      field: the current field

      value: the initial value for this field

      attrs: additional attributes for field

      req: required bool

      label: label for field

      tip: tooltip text for field

      comment: initial comment value for field 

    """

    attrs['class'] = "text_question"

    widget = widgets.TextInput(attrs=attrs)

    if not tip:

      tip = 'Please provide a short answer to this question.'

    question = CharField(help_text=tip, required=req, label=label,

                         widget=widget, max_length=140, initial=value)

    self.survey_fields[field] = question

    if not self.editing:

      widget = widgets.Textarea(attrs=attrs)

      comment = CharField(help_text=tip, required=False, label='Comments',

                          widget=widget, initial=comment)

      self.survey_fields['comment_for_' + field] = comment

  def addSingleField(self, field, value, attrs, schema, req=False, label='',

                     tip='', comment=''):

    """Add a selection field to this form.

    params:

      field: the current field

      value: the initial value for this field

      attrs: additional attributes for field

      schema: schema for survey

      req: required bool

      label: label for field

      tip: tooltip text for field

      comment: initial comment value for field

    """

    if self.editing:

      kind = schema[field]["type"]

      render = schema[field]["render"]

      widget = UniversalChoiceEditor(kind, render)

    else:

      widget = WIDGETS[schema[field]['render']](attrs=attrs)

    these_choices = []

    # add all properties, but select chosen one

    options = getattr(self.survey_content, field)

    has_record = not self.editing and self.survey_record

    if has_record and hasattr(self.survey_record, field):

      these_choices.append((value, value))

      if value in options:

        options.remove(value)

    for option in options:

      these_choices.append((option, option))

    if not tip:

      tip = 'Please select an answer this question.'

    question = PickOneField(help_text=tip, required=req, label=label,

                            choices=tuple(these_choices), widget=widget)

    self.survey_fields[field] = question

    if not self.editing:

      widget = widgets.Textarea(attrs=attrs)

      comment = CharField(help_text=tip, required=False, label='Comments',

                          widget=widget, initial=comment)

      self.survey_fields['comment_for_' + field] = comment

  def addMultiField(self, field, value, attrs, schema, req=False, label='',

                    tip='', comment=''):

    """Add a pick_multi field to this form.

    params:

      field: the current field

      value: the initial value for this field

      attrs: additional attributes for field

      schema: schema for survey

      req: required bool

      label: label for field

      tip: tooltip text for field

      comment: initial comment value for field

    """

    if self.editing:

      kind = schema[field]["type"]

      render = schema[field]["render"]

      widget = UniversalChoiceEditor(kind, render)

    else:

      widget = WIDGETS[schema[field]['render']](attrs=attrs)

    # TODO(ajaksu) need to allow checking checkboxes by default

    if self.survey_record and isinstance(value, basestring):

      # pass value as 'initial' so MultipleChoiceField renders checked boxes

      value = value.split(',')

    else:

      value = None

    these_choices = [(v,v) for v in getattr(self.survey_content, field)]

    if not tip:

      tip = 'Please select one or more of these choices.'

    question = PickManyField(help_text=tip, required=req, label=label,

                             choices=tuple(these_choices), widget=widget,

                             initial=value)

    self.survey_fields[field] = question

    if not self.editing:

      widget = widgets.Textarea(attrs=attrs)

      comment = CharField(help_text=tip, required=False, label='Comments',

                          widget=widget, initial=comment)

      self.survey_fields['comment_for_' + field] = comment

  def addQuantField(self, field, value, attrs, schema, req=False, label='',

                    tip='', comment=''):

    """Add a pick_quant field to this form.

    params:

      field: the current field

      value: the initial value for this field

      attrs: additional attributes for field

      schema: schema for survey

      req: required bool

      label: label for field

      tip: tooltip text for field

      comment: initial comment value for field

    """

    if self.editing:

      kind = schema[field]["type"]

      render = schema[field]["render"]

      widget = UniversalChoiceEditor(kind, render)

    else:

      widget = WIDGETS[schema[field]['render']](attrs=attrs)

    if self.survey_record:

      value = value

    else:

      value = None

    these_choices = [(v,v) for v in getattr(self.survey_content, field)]

    if not tip:

      tip = 'Please select one of these choices.'

    question = PickQuantField(help_text=tip, required=req, label=label,

                             choices=tuple(these_choices), widget=widget,

                             initial=value)

    self.survey_fields[field] = question

    if not self.editing:

      widget = widgets.Textarea(attrs=attrs)

      comment = CharField(help_text=tip, required=False, label='Comments',

                          widget=widget, initial=comment)

      self.survey_fields['comment_for_' + field] = comment

  class Meta(object):

    model = SurveyContent

    exclude = ['schema']

class UniversalChoiceEditor(widgets.Widget):

  """Edit interface for choice questions.

  Allows adding and removing options, re-ordering and editing option text.

  """

  def __init__(self, kind, render, attrs=None, choices=()):

    self.attrs = attrs or {}

    # Choices can be any iterable, but we may need to render this widget

    # multiple times. Thus, collapse it into a list so it can be consumed

    # more than once.

    self.choices = list(choices)

    self.kind = kind

    self.render_as = render

  def render(self, name, value, attrs=None, choices=()):

    """ renders UCE widget

    """

    if value is None:

      value = ''

    final_attrs = self.build_attrs(attrs, name=name)

    # find out which options should be selected in type and render drop-downs.

    selected = 'selected="selected"'

    context =  dict(

        name=name,

        is_selection=selected * (self.kind == 'selection'),

        is_pick_multi=selected * (self.kind == 'pick_multi'),

        is_pick_quant=selected * (self.kind == 'pick_quant'),

        is_select=selected * (self.render_as == 'single_select'),

        is_checkboxes=selected * (self.render_as == 'multi_checkbox'),

        is_radio_buttons=selected * (self.render_as == 'quant_radio'),

        )

    str_value = forms.util.smart_unicode(value) # normalize to string.

    chained_choices = enumerate(chain(self.choices, choices))

    choices = {}

    for i, (option_value, option_label) in chained_choices:

      option_value = escape(forms.util.smart_unicode(option_value))

      choices[i] = option_value

    context['choices'] = choices

    template = 'soc/survey/universal_choice_editor.html'

    return loader.render_to_string(template, context)

class PickOneField(forms.ChoiceField):

  """Stub for customizing the single choice field.

  """

  #TODO(james): Ensure that more than one option cannot be selected

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

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

class PickManyField(forms.MultipleChoiceField):

  """Stub for customizing the multiple choice field.

  """

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

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

class PickQuantField(forms.MultipleChoiceField):

  """Stub for customizing the multiple choice field.

  """

  #TODO(james): Ensure that more than one quant cannot be selected

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

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

class PickOneSelect(forms.Select):

  """Stub for customizing the single choice select widget.

  """

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

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

class PickManyCheckbox(forms.CheckboxSelectMultiple):

  """Customized multiple choice checkbox widget.

  """

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

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

  def render(self, name, value, attrs=None, choices=()):

    """Render checkboxes as list items grouped in a fieldset.

    This is the pick_multi widget for survey taking

    """

    if value is None:

      value = []

    has_id = attrs and attrs.has_key('id')

    final_attrs = self.build_attrs(attrs, name=name)

    # normalize to strings.

    str_values = set([forms.util.smart_unicode(v) for v in value])

    is_checked = lambda value: value in str_values

    smart_unicode = forms.util.smart_unicode

    # set container fieldset and list

    output = [u'<fieldset id="id_%s">\n  <ul class="pick_multi">' % name]

    # add numbered checkboxes wrapped in list items

    chained_choices = enumerate(chain(self.choices, choices))

    for i, (option_value, option_label) in chained_choices:

      option_label = escape(smart_unicode(option_label))

      # If an ID attribute was given, add a numeric index as a suffix,

      # so that the checkboxes don't all have the same ID attribute.

      if has_id:

        final_attrs = dict(final_attrs, id='%s_%s' % (attrs['id'], i))

      cb = widgets.CheckboxInput(final_attrs, check_test=is_checked)

      rendered_cb = cb.render(name, option_value)

      cb_label = (rendered_cb, option_label)

      output.append(u'    <li><label>%s %s</label></li>' % cb_label)

    output.append(u'  </ul>\n</fieldset>')

    return u'\n'.join(output)

  def id_for_label(self, id_):

    # see the comment for RadioSelect.id_for_label()

    if id_:

      id_ += '_fieldset'

    return id_

  id_for_label = classmethod(id_for_label)

class PickQuantRadioRenderer(widgets.RadioFieldRenderer):

  """Used by PickQuantRadio to enable customization of radio widgets.

  """

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

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

  def render(self):

    """Outputs set of radio fields in a div.

    """

    return mark_safe(u'<div class="quant_radio">\n%s\n</div>'

                     % u'\n'.join([u'%s' % force_unicode(w) for w in self]))

class PickQuantRadio(forms.RadioSelect):

  """TODO(James,Ajaksu) Fix Docstring

  """

  renderer = PickQuantRadioRenderer

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

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

# in the future, we'll have more widget types here