#!/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.

"""GradingRecord (Model) query functions.

"""

__authors__ = [

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

  ]

from google.appengine.ext import db

from soc.logic.models import base

from soc.logic.models.survey_record import grading_logic

from soc.logic.models.survey_record import project_logic

import soc.models.grading_record

class Logic(base.Logic):

  """Logic methods for the GradingRecord model.

  """

  def __init__(self, model=soc.models.grading_record.GradingRecord,

               base_model=None, scope_logic=None):

    """Defines the name, key_name and model for this entity.

    """

    super(Logic, self).__init__(model=model, base_model=base_model,

                                scope_logic=scope_logic, id_based=True)

  def updateOrCreateRecordsFor(self, survey_group, project_entities):

    """Updates or creates a GradingRecord in a batch.

    Args:

      survey_group: GradingSurveyGroup entity

      project_entities: list of project_entities which to process

    """

    records_to_store = []

    query_fields = {'grading_survey_group': survey_group}

    for project_entity in project_entities:

      # set a new project to query for

      query_fields['project'] = project_entity

      # try to retrieve an existing record

      record_entity = self.getForFields(query_fields, unique=True)

      # retrieve the fields that should be set

      record_fields = self.getFieldsForGradingRecord(project_entity,

                                                     survey_group,

                                                     record_entity)

      if not record_entity and project_entity.status in ['failed', 'invalid'] \

          and not record_fields['mentor_record'] \

          and not record_fields['student_record']:

        # Don't create a new GradingRecord for an already failed project which

        # has no records attached. Because it does not matter.

        continue

      if record_entity:

        # update existing GradingRecord

        for key,value in record_fields.iteritems():

          setattr(record_entity, key, value)

      else:

        # create a new GradingRecord

        record_entity = self.getModel()(**record_fields)

      # prepare the new/updated record for storage

      records_to_store.append(record_entity)

    # batch put and return the entities

    return db.put(records_to_store)

  def getFieldsForGradingRecord(self, project, survey_group,

                                record_entity=None):

    """Returns the fields for a GradingRecord.

    See GradingRecord model for description of the grade_decision value.

    Args:

      project: Project entity

      survey_group: a GradingSurveyGroup entity

      record_entity: an optional GradingRecord entity

    Returns:

      Dict containing the fields that should be set on a GradingRecord for this

      GradingSurveyGroup and StudentProject

    """

    # retrieve the two Surveys, student_survey might be None

    grading_survey = survey_group.grading_survey

    student_survey = survey_group.student_survey

    # retrieve a GradingSurveyRecord

    survey_record_fields = {'project': project,

                            'survey': grading_survey}

    grading_survey_record = grading_logic.getForFields(survey_record_fields,

                                                       unique=True)

    if student_survey:

      # retrieve ProjectSurveyRecord

      survey_record_fields['survey'] = student_survey

      project_survey_record = project_logic.getForFields(survey_record_fields,

                                                         unique=True)

    else:

      project_survey_record = None

    # set the necessary fields

    fields = {'grading_survey_group': survey_group,

              'project': project,

              'mentor_record': grading_survey_record,

              'student_record': project_survey_record}

    if not record_entity or not record_entity.locked:

      # find grading decision for new or unlocked records

      if not grading_survey_record:

        # no record found, return undecided

        grade_decision = 'undecided'

      elif not student_survey or project_survey_record:

        # if the grade is True then pass else fail

        grade_decision = 'pass' if grading_survey_record.grade else 'fail'

      else:

        # no ProjectSurveyRecord on file while there is a survey to be taken

        grade_decision = 'fail'

      fields['grade_decision'] = grade_decision

    # return the fields that should be set for a GradingRecord

    return fields

logic = Logic()