#!/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 ProjectSurveys.
"""

__authors__ = [
  '"Lennard de Rijk" <ljvderijk@gmail.com>',
  ]


from soc.logic import dicts
from soc.logic.models.survey import project_logic as project_survey_logic
from soc.logic.models.user import logic as user_logic
from soc.views import out_of_band
from soc.views.helper import access
from soc.views.helper import decorators
from soc.views.helper import lists
from soc.views.helper import redirects
from soc.views.models import survey


class View(survey.View):
  """View methods for the ProjectSurvey 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'] = [('checkIsSurveyReadable', project_survey_logic)]
    rights['create'] = ['checkIsUser']
    rights['edit'] = [('checkIsSurveyWritable', project_survey_logic)]
    rights['delete'] = ['checkIsDeveloper'] # TODO: fix deletion of Surveys
    rights['list'] = ['checkDocumentList']
    rights['take'] = [('checkIsSurveyTakeable', project_survey_logic),
                      ('checkIsAllowedToTakeProjectSurveyAs',
                       [project_survey_logic, 'student', 'project'])]


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

    new_params['name'] = "Project Survey"

    new_params['extra_dynaexclude'] = ['taking_access']

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

    super(View, self).__init__(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'])

    get_dict = request.GET

    if not 'project' in get_dict:
      # get the fields needed to filter projects on
      fields = self._constructFilterForProjectSelection(entity, params)

      # show project selection screen using the given filter
      return self._selectProjects(request, page_name, params, entity, fields)

    return super(View, self).take(request, 'any_access', page_name=page_name,
                                  params=params, **kwargs)

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

    This method also take the StudentProject specified as GET param into
    account when querying for the SurveyRecord.

    For params see survey.View._getSurveyRecordFor().
    """

    from soc.logic.models.student_project import logic as student_project_logic

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

    user_entity = user_logic.getForCurrentAccount()

    # get the StudentProject specified in the GET params
    project_key_name = request.GET['project']
    project_entity = student_project_logic.getFromKeyName(project_key_name)

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

    return record_logic.getForFields(filter, unique=True)

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

    For params see survey.View._takeGet().
    """

    # the form action should contain the requested project
    context['form_action'] = "?project=%s" %(request.GET['project'])

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

    This is used to ensure the right StudentProject gets stored

    For params see survey.View._takePost().
    """

    from soc.logic.models.student_project import logic as student_project_logic

    # retrieve the project using the key name in the GET param
    get_dict = request.GET
    project_entity = student_project_logic.getFromKeyName(get_dict['project'])

    # update the properties that will be stored with the referenced project
    properties.update(project=project_entity)

  def _constructFilterForProjectSelection(self, survey, params):
    """Returns the filter needed for the Project selection view.

    Returns a filter for all the valid projects for which the current user
    is a student. Of course only in the survey's scope.

    Args:
      survey: a Survey entity
      params: the params dict for the requesting view

    Returns:
      Dictionary that can be used as a input for a query.
    """

    from soc.logic.models.student import logic as student_logic

    survey_logic = params['logic']

    user_entity = user_logic.getForCurrentAccount()

    # get the student entity for the current user and program
    fields = {'user': user_entity,
              'scope': survey_logic.getScope(survey),
              'status': 'active'}

    student_entity = student_logic.getForFields(fields, unique=True)

    # TODO(ljvderijk) transform StudentProject to handle multiple surveys
    fields = {'student': student_entity,
              'status': 'accepted'}

    return fields

  def _selectProjects(self, request, page_name, params, survey, fields):
    """Shows a view upon which a User can select a Student Project to fill in
    the ProjectSurvey for.

    Args:
      survey: a Survey entity
      fields: the filter to use on the Project List
      rest: see base.View.public()
    """

    from soc.views.models.student_project import view as student_project_view

    student_project_params = student_project_view.getParams().copy()

    redirect_dict = {'survey': survey,
                     'params': params}

    student_project_params['list_action'] = (
        redirects.getTakeProjectSurveyRedirect, redirect_dict)
    student_project_params['list_description'] = (
        "Select a %s for which to fill in the %s named %s" %(
            student_project_params['name'], params['name'], survey.title))

    content = lists.getListContent(request, student_project_params, fields)
    contents = [content]

    return self._list(request, student_project_params, contents, page_name)


view = View()

create = decorators.view(view.create)
edit = decorators.view(view.edit)
delete = decorators.view(view.delete)
list = decorators.view(view.list)
public = decorators.view(view.public)
take = decorators.view(view.take)
