#!/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.

"""Appengine Tasks related to GHOP Task handling.

"""

__authors__ = [

    '"Madhusudan.C.S" <madhusudancs@gmail.com>'

  ]

import logging

import os

from google.appengine.api.labs import taskqueue

from google.appengine.ext import db

from django import http

from django.utils.translation import ugettext

from soc.tasks.helper import error_handler

from soc.views.helper import redirects

from soc.modules.ghop.logic.models import task as ghop_task_logic

DEF_TASK_UPDATE_SUBJECT_FMT = ugettext('[GHOP Task Update] %(title)s')

def getDjangoURLPatterns():

  """Returns the URL patterns for the tasks in this module.

  """

  patterns = [

      (r'^tasks/ghop/task/update$',

       'soc.modules.ghop.tasks.task_update.updateGHOPTask'),

      (r'^tasks/ghop/task/update/student_status$',

       'soc.modules.ghop.tasks.task_update.updateTasksPostStudentSignUp')]

  return patterns

def spawnUpdateTask(entity):

  """Spawns a task to update the state of the task. 

  """

  update_params = {

      'ghop_task_key': entity.key().name(),

      }

  update_url = '/tasks/ghop/task/update'

  new_task = taskqueue.Task(eta=entity.deadline, 

                            params=update_params,

                            url=update_url)

  new_task.add('ghop-update')

def updateGHOPTask(request, *args, **kwargs):

  """Method executed by Task Queue API to update a GHOP Task to

  relevant state.

  Expects the ghop_task_key entry to be present in the POST dict.

  Args:

    request: the standard Django HTTP request object 

  """

  post_dict = request.POST

  key_name = post_dict.get('ghop_task_key')

  if not key_name:

    # invalid task data, log and return OK

    return error_handler.logErrorAndReturnOK(

        'Invalid updateGHOPTask data: %s' % post_dict)

  entity = ghop_task_logic.logic.getFromKeyNameOr404(key_name)

  entity, comment_entity, ws_entity = ghop_task_logic.logic.updateTaskStatus(

      entity)

  if entity:

    # TODO(madhusudan): does this really mean an unsuccessful update?

    # return OK

    return http.HttpResponse()

def updateTasksPostStudentSignUp(request, *args, **kwargs):

  """Appengine task that updates the GHOP Tasks after the student signs up.

  Expects the following to be present in the POST dict:

    student_key: Specifies the student key name who registered

  Args:

    request: Django Request object

  """

  from soc.modules.ghop.logic.models import student as ghop_student_logic

  post_dict = request.POST

  student_key = post_dict.get('student_key')

  if not student_key:

    # invalid student data, log and return OK

    return error_handler.logErrorAndReturnOK(

        'Invalid Student data: %s' % post_dict)

  student_entity = ghop_student_logic.logic.getFromKeyNameOr404(student_key)

  # retrieve all tasks currently assigned to the user

  task_fields = {

      'user': student_entity.user,

      }

  task_entities = ghop_task_logic.logic.getForFields(task_fields)

  # TODO(madhusudan) move this to the Task Logic

  # Make sure the tasks store references to the student as well as

  # closing all tasks that are AwaitingRegistration.

  for task_entity in task_entities:

    task_entity.student = student_entity

    if task_entity.status == 'AwaitingRegistration':

      task_entities.remove(task_entity)

      properties = {'status': 'Closed'}

      changes = [ugettext('User-MelangeAutomatic'),

                 ugettext('Action-Student registered'),

                 ugettext('Status-%s' % (properties['status']))]

      comment_properties = {

          'parent': task_entity,

          'scope_path': task_entity.key().name(),

          'created_by': None,

          'changes': changes,

          'content': ugettext(

              '(The Melange Automated System has detected that the student '

              'has signed up for the program and hence has closed this task.'),

          }

      ghop_task_logic.logic.updateEntityPropertiesWithCWS(

          task_entity, properties, comment_properties)

  db.put(task_entities)

  # return OK

  return http.HttpResponse()