#!/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.

"""Views for Surveys.
"""

__authors__ = [
  '"Daniel Diniz" <ajaksu@gmail.com>',
  '"James Levy" <jamesalexanderlevy@gmail.com>',
  '"Lennard de Rijk" <ljvderijk@gmail.com>',
  ]

import datetime
import re
import string

from google.appengine.ext import db

from django import forms
from django import http
from django.utils import simplejson

from soc.logic import cleaning
from soc.logic import dicts
from soc.logic.helper import timeline
from soc.logic.models.survey import logic as survey_logic
from soc.logic.models.user import logic as user_logic
from soc.models.survey import Survey
from soc.models.survey_record import SurveyRecord
from soc.models.user import User
from soc.views import out_of_band
from soc.views.helper import access
from soc.views.helper import decorators
from soc.views.helper import forms as forms_helper
from soc.views.helper import lists
from soc.views.helper import redirects
from soc.views.helper import responses
from soc.views.helper import surveys
from soc.views.helper import widgets
from soc.views.models import base


CHOICE_TYPES = set(('selection', 'pick_multi', 'choice', 'pick_quant'))
TEXT_TYPES = set(('long_answer', 'short_answer'))
PROPERTY_TYPES = tuple(CHOICE_TYPES) + tuple(TEXT_TYPES)

# used in View.getSchemaOptions to map POST values
BOOL = {'True': True, 'False': False}

_short_answer = ("Short Answer",
                "Less than 40 characters. Rendered as a text input. "
                "It's possible to add a free form question (Content) "
                "and a in-input prompt/example text.")
_choice = ("Selection",
           "Can be set as a single choice (selection) or multiple choice "
           "(pick_multi) question. Rendered as a select (single choice) "
           "or a group of checkboxes (multiple choice). It's possible to "
           "add a free form question (Content) and as many free form options "
           "as wanted. Each option can be edited (double-click), deleted "
           "(click on (-) button) or reordered (drag and drop).")
_long_answer = ("Long Answer",
                "Unlimited length, auto-growing field. Rendered as a textarea. "
                 "It's possible to add a free form question (Content) and "
                 "an in-input prompt/example text.")
QUESTION_TYPES = dict(short_answer=_short_answer, long_answer=_long_answer,
                      choice=_choice)

# for to_csv and View.exportSerialized
FIELDS = 'author modified_by'
PLAIN = 'is_featured content created modified'


class View(base.View):
  """View methods for the Survey model.
  """

  def __init__(self, params=None):
    """Defines the fields and methods required for the base View class
    to provide the user with list, public, create, edit and delete views.

    Params:
      params: a dict with params for this View
    """

    rights = access.Checker(params)
    rights['any_access'] = ['allow']
    rights['show'] = [('checkIsSurveyWritable', survey_logic)]
    rights['create'] = ['checkIsUser']
    rights['edit'] = [('checkIsSurveyWritable', survey_logic)]
    rights['delete'] = ['checkIsDeveloper'] # TODO: fix deletion of Surveys
    rights['list'] = ['checkDocumentList']
    rights['pick'] = ['checkDocumentPick']
    rights['results'] = [('checkIsSurveyWritable', survey_logic)]
    rights['take'] = [('checkIsSurveyTakeable', survey_logic)]

    new_params = {}
    new_params['logic'] = survey_logic
    new_params['rights'] = rights

    new_params['name'] = 'Survey'
    new_params['sidebar_grouping'] = "Surveys"

    new_params['extra_django_patterns'] = [
         (r'^%(url_name)s/(?P<access_type>take)/%(key_fields)s$',
         'soc.views.models.%(module_name)s.take',
         'Take %(name)s'),
         (r'^%(url_name)s/(?P<access_type>json)/%(scope)s$',
         'soc.views.models.%(module_name)s.json',
         'Export %(name)s as JSON'),
        (r'^%(url_name)s/(?P<access_type>results)/%(key_fields)s$',
         'soc.views.models.%(module_name)s.results',
         'View survey results for %(name)s'),
        (r'^%(url_name)s/(?P<access_type>show)/user/(?P<link_id>)\w+$',
         'soc.views.models.%(module_name)s.results',
         'View survey results for user'),
        ]

    new_params['export_content_type'] = 'text/text'
    new_params['export_extension'] = '.csv'
    new_params['export_function'] = surveys.to_csv(self)
    new_params['delete_redirect'] = '/'
    new_params['list_key_order'] = [
        'link_id', 'scope_path', 'name', 'short_name', 'title',
        'content', 'prefix','read_access','write_access']

    new_params['edit_template'] = 'soc/survey/edit.html'
    new_params['create_template'] = 'soc/survey/edit.html'
    new_params['public_template'] = 'soc/survey/public.html'
    new_params['take_template'] = 'soc/survey/take.html'

    # TODO which one of these are leftovers from Document?
    new_params['no_create_raw'] = True
    new_params['no_create_with_scope'] = True
    new_params['no_create_with_key_fields'] = True
    new_params['no_list_raw'] = True
    new_params['sans_link_id_create'] = True
    new_params['sans_link_id_list'] = True

    new_params['create_dynafields'] = [
        {'name': 'link_id',
         'base': forms.fields.CharField,
         'label': 'Survey Link ID',
         },
        ]

    new_params['create_extra_dynaproperties'] = {
        'content': forms.fields.CharField(required=False, label='Description',
            widget=widgets.FullTinyMCE(attrs={'rows': 25, 'cols': 100})),
        'survey_html': forms.fields.CharField(widget=forms.HiddenInput,
                                              required=False),
        'scope_path': forms.fields.CharField(widget=forms.HiddenInput,
                                             required=True),
        'prefix': forms.fields.CharField(widget=widgets.ReadOnlyInput(),
                                        required=True),
        'clean_content': cleaning.clean_html_content('content'),
        'clean_link_id': cleaning.clean_link_id('link_id'),
        'clean_scope_path': cleaning.clean_scope_path('scope_path'),
        'clean': cleaning.validate_document_acl(self, True),
        }

    new_params['extra_dynaexclude'] = ['author', 'created',
                                       'home_for', 'modified_by', 'modified',
                                       'take_survey', 'survey_content']

    new_params['edit_extra_dynaproperties'] = {
        'doc_key_name': forms.fields.CharField(widget=forms.HiddenInput),
        'created_by': forms.fields.CharField(widget=widgets.ReadOnlyInput(),
                                             required=False),
        'last_modified_by': forms.fields.CharField(
                                widget=widgets.ReadOnlyInput(), required=False),
        'clean': cleaning.validate_document_acl(self),
        }

    params = dicts.merge(params, new_params, sub_merge=True)

    super(View, self).__init__(params=params)

  def list(self, request, access_type, page_name=None, params=None,
           filter=None, order=None, **kwargs):
    """See base.View.list.
    """

    return super(View, self).list(request, access_type, page_name=page_name,
                                  params=params, filter=kwargs)

  def _public(self, request, entity, context):
    """Add a preview version of the Survey to the page's context.

    Args:
      request: the django request object
      entity: the entity to make public
      context: the context object
    """

    # construct the form to be shown on the page
    # TODO(ljvderijk) Generate SurveyForm without passing along the logic
    survey_form = surveys.SurveyTakeForm(survey_content=entity.survey_content,
                                         survey_logic=self._params['logic'])

    # TOOD(ljvderijk) pose question about the getFields method name and working
    survey_form.getFields()

    context['survey_form'] = survey_form

    # return True to signal that the page may be displayed
    return True

  def _editPost(self, request, entity, fields):
    """See base.View._editPost().

    Processes POST request items to add new dynamic field names,
    question types, and default prompt values to SurveyContent model.
    """

    user = user_logic.getForCurrentAccount()
    schema = {}
    survey_fields = {}

    if not entity:
      # new Survey
      if 'serialized' in request.POST:
        fields, schema, survey_fields = self.importSerialized(request, fields,
                                                              user)
      fields['author'] = user
    else:
      fields['author'] = entity.author
      schema = self.loadSurveyContent(schema, survey_fields, entity)

    # remove deleted properties from the model
    self.deleteQuestions(schema, survey_fields, request.POST)

    # add new text questions and re-build choice questions
    self.getRequestQuestions(schema, survey_fields, request.POST)

    # get schema options for choice questions
    self.getSchemaOptions(schema, survey_fields, request.POST)

    survey_content = getattr(entity,'survey_content', None)
    # create or update a SurveyContent for this Survey
    survey_content = survey_logic.createSurvey(survey_fields, schema,
                                                survey_content=survey_content)

    # save survey_content for existent survey or pass for creating a new one
    if entity:
      entity.modified_by = user
      entity.survey_content = survey_content
      db.put(entity)
    else:
      fields['survey_content'] = survey_content

    fields['modified_by'] = user

    super(View, self)._editPost(request, entity, fields)

  def loadSurveyContent(self, schema, survey_fields, entity):
    """Populate the schema dict and get text survey questions.
    """

    if hasattr(entity, 'survey_content'):

      # there is a SurveyContent already
      survey_content = entity.survey_content
      schema = eval(survey_content.schema)

      for question_name in survey_content.dynamic_properties():

        # get the current questions from the SurveyContent
        if question_name not in schema:
          continue

        if schema[question_name]['type'] not in CHOICE_TYPES:
          # Choice questions are always regenerated from request, see
          # self.get_request_questions()
          question = getattr(survey_content, question_name)
          survey_fields[question_name] = question

    return schema

  def deleteQuestions(self, schema, survey_fields, POST):
    """Process the list of questions to delete, from a hidden input.
    """

    deleted = POST.get('__deleted__', '')

    if deleted:
      deleted = deleted.split(',')
      for field in deleted:

        if field in schema:
          del schema[field]

        if field in survey_fields:
          del survey_fields[field]

  def getRequestQuestions(self, schema, survey_fields, POST):
    """Get fields from request.

    We use two field/question naming and processing schemes:
      - Choice questions consist of <input/>s with a common name, being rebuilt
        anew on every edit POST so we can gather ordering, text changes,
        deletions and additions.
      - Text questions only have special survey__* names on creation, afterwards
        they are loaded from the SurveyContent dynamic properties.
    """

    for key, value in POST.items():

      if key.startswith('id_'):
        # Choice question fields, they are always generated from POST contents,
        # as their 'content' is editable and they're reorderable. Also get
        # its field index for handling reordering fields later.
        name, number = key[3:].replace('__field', '').rsplit('_', 1)

        if name not in schema:
          if 'NEW_' + name in POST:
            # new Choice question, set generic type and get its index
            schema[name] = {'type': 'choice'}

        if name in schema and schema[name]['type'] in CHOICE_TYPES:
          # build an index:content dictionary
          if name in survey_fields:
            if value not in survey_fields[name]:
              survey_fields[name][int(number)] = value
          else:
            survey_fields[name] = {int(number): value}

      elif key.startswith('survey__'): # Text question
        # this is super ugly but unless data is serialized the regex is needed
        prefix = re.compile('survey__([0-9]{1,3})__')
        prefix_match = re.match(prefix, key)

        index = prefix_match.group(0).replace('survey', '').replace('__','')
        index = int(index)

        field_name = prefix.sub('', key)
        field = 'id_' + key

        for ptype in PROPERTY_TYPES:
          # should only match one
          if ptype + "__" in field_name:
            field_name = field_name.replace(ptype + "__", "")
            if field_name not in schema:
              schema[field_name]= {}
            schema[field_name]["index"] = index
            schema[field_name]["type"] = ptype

        # store text question tooltip from the input/textarea value
        schema[field_name]["tip"] = value

        # add the question as a dynamic property to survey_content
        survey_fields[field_name] = value

  def getSchemaOptions(self, schema, survey_fields, POST):
    """Get question, type, rendering and option order for choice questions.
    """

    RENDER = {'checkboxes': 'multi_checkbox', 'select': 'single_select',
              'radio_buttons': 'quant_radio'}

    RENDER_TYPES = {'select': 'selection',
                    'checkboxes': 'pick_multi',
                    'radio_buttons': 'pick_quant' }

    for key in schema:
      if schema[key]['type'] in CHOICE_TYPES and key in survey_fields:
        render_for = 'render_for_' + key
        if render_for in POST:
          schema[key]['render'] = RENDER[POST[render_for]]
          schema[key]['type'] = RENDER_TYPES[POST[render_for]]

        # set the choice question's tooltip
        tip_for = 'tip_for_' + key
        schema[key]['tip'] = POST.get(tip_for)

        # handle reordering fields
        ordered = False
        order = 'order_for_' + key
        if order in POST and isinstance(survey_fields[key], dict):
          order = POST[order]

          # 'order_for_name' is jquery serialized from a sortable, so it's in
          # a 'name[]=1&name[]=2&name[]=0' format ('id-li-' is set in our JS)
          order = order.replace('id-li-%s[]=' % key, '')
          order = order.split('&')

          if len(order) == len(survey_fields[key]) and order[0]:
            order = [int(number) for number in order]

            if set(order) == set(survey_fields[key]):
              survey_fields[key] = [survey_fields[key][i] for i in order]
              ordered = True

          if not ordered:
            # we don't have a good ordering to use
            ordered = sorted(survey_fields[key].items())
            survey_fields[key] = [value for index, value in ordered]

      # set 'question' entry (free text label for question) in schema
      question_for = 'NEW_' + key
      if question_for in POST and POST[question_for]:
        schema[key]["question"] = POST[question_for]

      # set wheter the question is required
      required_for = 'required_for_' + key
      schema[key]['required'] = BOOL[POST[required_for]]

      # set wheter the question allows comments
      comment_for = 'comment_for_' + key
      schema[key]['has_comment'] = BOOL[POST[comment_for]]

      # set the question index from JS-calculated value
      index_for = 'index_for_' + key
      if index_for in POST:
        schema[key]['index'] = int(POST[index_for].replace('__', ''))

  def createGet(self, request, context, params, seed):
    """Pass the question types for the survey creation template.
    """

    context['question_types'] = QUESTION_TYPES

    # avoid spurious results from showing on creation
    context['new_survey'] = True
    return super(View, self).createGet(request, context, params, seed)

  def editGet(self, request, entity, context, params=None):
    """Process GET requests for the specified entity.

    Builds the SurveyForm that represents the Survey question contents.
    """

    self._entity = entity
    survey_content = entity.survey_content

    survey_form = surveys.SurveyEditForm(survey_content=survey_content,
                                         survey_logic=params['logic'])
    survey_form.getFields()

    local = dict(survey_form=survey_form, question_types=QUESTION_TYPES,
                survey_h=entity.survey_content)
    context.update(local)

    params['edit_form'] = surveys.HelperForm(params['edit_form'])
    if entity.survey_end and datetime.datetime.now() > entity.survey_end:
      # are we already passed the survey_end?
      context["passed_survey_end"] = True

    return super(View, self).editGet(request, entity, context, params=params)

  @decorators.merge_params
  @decorators.check_access
  def take(self, request, access_type, page_name=None,
           params=None, **kwargs):
    """View for taking a Survey.

    For Args see base.View().public().
    """

    survey_logic = params['logic']

    try:
      entity = survey_logic.getFromKeyFieldsOr404(kwargs)
    except out_of_band.Error, error:
      return responses.errorResponse(
          error, request, template=params['error_public'])

    template = params['take_template']

    # get the context for this webpage
    context = responses.getUniversalContext(request)
    responses.useJavaScript(context, params['js_uses_all'])
    context['page_name'] = "%s titled '%s'" % (page_name, entity.title)
    context['entity'] = entity

    # try to get an existing SurveyRecord for the current user
    survey_record = self._getSurveyRecordFor(entity, request, params)

    # get an instance of SurveyTakeForm to use
    survey_form = self._getSurveyTakeForm(entity, survey_record, params,
                                          request.POST)

    # fill context with the survey_form and additional information
    context['survey_form'] = survey_form
    self.setHelpAndStatus(context, entity, survey_record)

    if request.POST:
      return self.takePost(request, template, context, params, survey_form,
                           entity, survey_record, **kwargs)
    else: #request.GET
      return self.takeGet(request, template, context, params, survey_form,
                          entity, survey_record, **kwargs)

  def _getSurveyRecordFor(self, survey, request, params):
    """Returns the SurveyRecord for the given Survey and request.

    Args:
        survey: a Survey entity
        request: a Django HTTPRequest object
        params: params for the requesting view

    Returns:
        An existing SurveyRecord iff any exists for the given Survey, request
        and any other conditions that must apply.
    """

    survey_logic = params['logic']
    record_logic = survey_logic.getRecordLogic()

    user_entity = user_logic.getForCurrentAccount()

    filter = {'survey': survey,
              'user': user_entity}

    return record_logic.getForFields(filter, unique=True)

  def _getSurveyTakeForm(self, survey, record, params, post_dict=None):
    """Returns the specific SurveyTakeForm needed for the take view.

    Args:
        survey: a Survey entity
        record: a SurveyRecord instance if any exist
        params: the params dict for the requesting View
        post_dict: POST data to be passed to form initialization

    Returns:
        An instance of SurveyTakeForm that can be used to take a Survey.
    """

    return surveys.SurveyTakeForm(survey_content=survey.survey_content,
                                  survey_record=record,
                                  survey_logic=params['logic'],
                                  data=post_dict)


  def takeGet(self, request, template, context, params, survey_form, entity,
              record, **kwargs):
    """Handles the GET request for the Survey's take page.

    Args:
        template: the template used for this view
        survey_form: instance of SurveyTakeForm
        entity: the Survey entity
        record: a SurveyRecord entity iff any exists
        rest: see base.View.public()
    """

    # call the hook method
    self._takeGet(request, template, context, params, entity, record, **kwargs)

    return responses.respond(request, template, context)

  def _takeGet(self, request, template, context, params, entity, record,
               **kwargs):
    """Hook for the GET request for the Survey's take page.

    This method is called just before the GET page is shown.

    Args:
        template: the template used for this view
        entity: the Survey entity
        record: a SurveyRecord entity
        rest: see base.View.public()
    """
    pass

  def takePost(self, request, template, context, params, survey_form, entity,
               record, **kwargs):
    """Handles the POST request for the Survey's take page.

    Args:
        template: the template used for this view
        survey_form: instance of SurveyTakeForm
        entity: the Survey entity
        record: a SurveyRecord entity
        rest: see base.View.public()
    """

    survey_logic = params['logic']
    record_logic = survey_logic.getRecordLogic()

    if not survey_form.is_valid():
      # show the form errors
      return self._constructResponse(request, entity=entity, context=context,
                                     form=survey_form, params=params,
                                     template=template)

    # retrieve the data from the form
    _, properties = forms_helper.collectCleanedFields(survey_form)

    # add the required SurveyRecord properties
    properties['user'] = user_logic.getForCurrentAccount()
    properties['survey'] = entity

    # call the hook method before updating the SurveyRecord
    self._takePost(request, params, entity, record, properties)

    # update the record entity if any and clear all dynamic properties
    record_logic.updateOrCreateFromFields(record, properties,
                                          clear_dynamic=True)

    # TODO: add notice to page that the response has been saved successfully
    # redirect to the same page for now
    redirect = request.path
    return http.HttpResponseRedirect(redirect)

  def _takePost(self, request, params, entity, record, properties):
    """Hook for the POST request for the Survey's take page.

    This method is called just before the SurveyRecord is stored.

    Args:
        request: Django Request object
        params: the params for the current view
        entity: a Survey entity
        record: a SurveyRecord entity
        properties: properties to be stored in the SurveyRecord entity
    """
    pass


  def setHelpAndStatus(self, context, survey, survey_record):
    """Get help_text and status for template use.

    Args:
        context: the context for the view to update
        survey: a Survey entity
        survey_record: a SurveyRecordEntity
    """

    if not survey.survey_end:
      survey_end_text = ""
    else:
      survey_end_text = " by " + str(
          survey.survey_end.strftime("%A, %d. %B %Y %I:%M%p"))

    if survey_record:
      help_text = "You may edit and re-submit this survey" + survey_end_text + "."
      status = "edit"
    else:
      help_text = "Please complete this survey" + survey_end_text + "."
      status = "create"

    # update the context with the help_text and status
    context_update = dict(status=status, help_text=help_text)
    context.update(context_update)

  def activate(self, request, **kwargs):
    """This is a hack to support the 'Enable grades' button.
    """
    self.activateGrades(request)
    redirect_path = request.path.replace('/activate/', '/edit/') + '?activate=1'
    return http.HttpResponseRedirect(redirect_path)

  def activateGrades(self, request, **kwargs):
    """Updates SurveyRecord's grades for a given Survey.
    """
    survey_key_name = survey_logic.getKeyNameFromPath(request.path)
    survey = Survey.get_by_key_name(survey_key_name)
    survey_logic.activateGrades(survey)
    return

  @decorators.merge_params
  @decorators.check_access
  def viewResults(self, request, access_type, page_name=None,
                  params=None, **kwargs):
    """View for SurveyRecords.

    For params see base.View.public().
    """

    survey_logic = params['logic']

    try:
      entity = survey_logic.getFromKeyFieldsOr404(kwargs)
    except out_of_band.Error, error:
      return responses.errorResponse(
          error, request, template=params['error_public'])

    # get the context for this webpage
    context = responses.getUniversalContext(request)
    responses.useJavaScript(context, params['js_uses_all'])
    context['page_name'] = "%s titled '%s'" % (page_name, entity.title)
    context['entity'] = entity

    results_logic = survey_logic.getRecordLogic()

    user = user_logic.getForCurrentAccount()

    context['properties'] = entity.survey_content.orderedProperties()

    filter = self._params.get('filter') or {}

    filter['survey'] = entity

    list_params = params.copy()
    list_params['list_description'] = \
      'List of  %(name_plural)s.' % list_params

    list_params['logic'] = results_logic

    valid_list = lists.getListContent(request, list_params, filter, idx=0)

    valid_list['row'] = 'soc/survey/list/results_row.html'
    valid_list['heading'] = 'soc/survey/list/results_heading.html'
    valid_list['description'] = 'Survey Results:'

    contents = []
    # fill contents with all the needed lists
    contents.append(valid_list)

    return self._list(request, list_params, contents, page_name, context)

  @decorators.merge_params
  @decorators.check_access
  def exportSerialized(self, request, access_type, page_name=None,
                       params=None, **kwargs):

    sur, context = self.getContextEntity(request, page_name, params, kwargs)

    if context is None:
      # user cannot see this page, return error response
      return sur

    json = sur.toDict()
    json.update(dict((f, str(getattr(sur, f))) for f in PLAIN.split()))
    static = ((f, str(getattr(sur, f).link_id)) for f in FIELDS.split())
    json.update(dict(static))

    dynamic = sur.survey_content.dynamic_properties()
    content = ((prop, getattr(sur.survey_content, prop)) for prop in dynamic)
    json['survey_content'] = dict(content)

    schema =  sur.survey_content.schema
    json['survey_content']['schema'] = eval(sur.survey_content.schema)

    data = simplejson.dumps(json, indent=2)

    return self.json(request, data=json)

  def importSerialized(self, request, fields, user):
    json = request.POST['serialized']
    json = simplejson.loads(json)['data']
    survey_content = json.pop('survey_content')
    schema = survey_content.pop('schema')
    del json['author']
    del json['created']
    del json['modified']
    #del json['is_featured']
    # keywords can't be unicode
    keywords = {}
    for key, val in json.items():
      keywords[str(key)] = val
    if 'is_featured' in keywords:
      keywords['is_featured'] = eval(keywords['is_featured'])
    return keywords, schema, survey_content

  def getContextEntity(self, request, page_name, params, kwargs):
    context = responses.getUniversalContext(request)
    responses.useJavaScript(context, params['js_uses_all'])
    context['page_name'] = page_name
    entity = None

    # TODO(ajaksu) there has to be a better way in this universe to get these
    kwargs['prefix'] = 'program'
    kwargs['link_id'] = request.path.split('/')[-1]
    kwargs['scope_path'] = '/'.join(request.path.split('/')[4:-1])

    entity = survey_logic.getFromKeyFieldsOr404(kwargs)

    if not self._public(request, entity, context):
      error = out_of_band.Error('')
      error = responses.errorResponse(
          error, request, template=params['error_public'], context=context)
      return error, None

    return entity, context

  def getMenusForScope(self, entity, params, id, user):
    """List featured surveys if after the survey_start date 
    and before survey_end an iff the current user has the right taking access.

    Args:
      entity: entity which is the scope for a Survey
      params: params from the requesting View
      id: GAE user instance for the current user
      user: User entity from the current user
    """

    # only list surveys for registered users
    if not user:
      return []

    survey_params = self.getParams().copy()
    survey_logic = survey_params['logic']
    record_logic = survey_logic.getRecordLogic()

    # filter all featured surveys for the given entity
    filter = {
        'prefix' : params['url_name'],
        'scope_path': entity.key().id_or_name(),
        'is_featured': True,
        }

    survey_entities = survey_logic.getForFields(filter)
    submenus = []

    # get the rights checker
    rights = self._params['rights']
    rights.setCurrentUser(id, user)

    # cache ACL
    survey_rights = {}

    # add a link to all featured active surveys the user can take
    for survey_entity in survey_entities:

      if survey_entity.taking_access not in survey_rights:
        # we have not determined if this user has the given type of access

        # check if the current user is allowed to visit the take Survey page
        allowed_to_take = False

        try:
          rights.checkIsSurveyTakeable(
              {'key_name': survey_entity.key().name(),
               'prefix': survey_entity.prefix,
               'scope_path': survey_entity.scope_path,
               'link_id': survey_entity.link_id,
               'user': user},
              survey_logic,
              check_time=False)
          allowed_to_take = True
        except:
          pass

        # cache ACL for a given entity.taking_access
        survey_rights[survey_entity.taking_access] = allowed_to_take

        if not allowed_to_take:
          # not allowed to take this survey
          continue

      elif not survey_rights[survey_entity.taking_access]:
        # we already determined that the user doens't have access to this type
        continue

      if not timeline.isActivePeriod(survey_entity, 'survey'):
        # this survey is not active right now
        continue

      # check if any SurveyRecord is available for this survey
      filter = {'survey': survey_entity,
                'user': user}

      survey_record = record_logic.getForFields(filter, unique=True)

      if survey_record:
        taken_status = ""
      else:
        # no SurveyRecord available so we mark the survey as new
        taken_status = "(new)"

      submenu = (redirects.getTakeSurveyRedirect(survey_entity, survey_params),
                 'Survey ' + taken_status + ': ' + survey_entity.short_name,
                 'show')

      submenus.append(submenu)
    return submenus


view = View()

admin = decorators.view(view.admin)
create = decorators.view(view.create)
edit = decorators.view(view.edit)
export = decorators.view(view.export)
delete = decorators.view(view.delete)
json = decorators.view(view.exportSerialized)
list = decorators.view(view.list)
public = decorators.view(view.public)
pick = decorators.view(view.pick)
results = decorators.view(view.viewResults)
take = decorators.view(view.take)
