#!/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.

"""SurveyRecordGroup represents a cluster (mentor/student) of SurveyRecords

for an evaluation period.

"""

__authors__ = [

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

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

]

from google.appengine.ext import db

from soc.models.survey_record import SurveyRecord

import soc.models.user

class SurveyRecordGroup(db.Expando):

  """Because Mentors and Students take different surveys,

  we cannot simply link survey records by a common project and survey.

  Instead, we establish a SurveyRecordGroup.

  A SurveyRecordGroup links a group of survey records with a common

  project, and links back to its records. 

  This entity also includes the current project_status at its creation.

  This property is used as a filter in lookups and acts as a safeguard

  against unpredictable behavior. 

  """

  #: Mentor SurveyRecord for this evaluation.

  mentor_record = db.ReferenceProperty(SurveyRecord, required=False,

                              collection_name='mentor_record_groups')

  #: Student SurveyRecord for this evaluation.

  student_record = db.ReferenceProperty(SurveyRecord, required=False,

                              collection_name='student_record_groups')

  #: Project for this evaluation.

  project = db.ReferenceProperty(soc.models.student_project.StudentProject,

                                collection_name="survey_record_groups",

                                required=True)

  # Status of project at start of evaluation.

  initial_status = db.StringProperty(required=True)

  #: Status of project at end of evaluation.

  final_status = db.StringProperty(required=False)

  #: Property containing the date that this SurveyRecordGroup was created.

  created = db.DateTimeProperty(auto_now_add=True)

  #: Property containing the last date that this SurveyRecordGroup was modified.

  modified = db.DateTimeProperty(auto_now=True)