#!/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.

"""Version update Tasks runner.

"""

__authors__ = [

  '"Sverre Rabbelier" <sverre@rabbelier.nl>',

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

  ]

from django import http

from django.template import loader

from django.utils.translation import ugettext

from soc.tasks.helper import error_handler

from soc.tasks.updates import student_school_type

from soc.views.helper import responses

def getDjangoURLPatterns():

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

  """

  patterns = [

      (r'tasks/update/start$', 'soc.tasks.updates.start_update.startTasks'),

      (r'tasks/update/start/([0-9_a-z]+)$',

       'soc.tasks.updates.start_update.start_task'),

      (r'tasks/update/run/([0-9_a-z]+)$',

       'soc.tasks.updates.start_update.run_task')]

  return patterns

def startTasks(request):

  """Presents a view that allows the user to start update tasks.

  """

  template = 'soc/tasks/start_update.html'

  context = responses.getUniversalContext(request)

  options = task_runner.getOptions()

  sorted_keys = []

  for key, option in options.iteritems():

    option['name'] = key

    sorted_keys.append(

        (option['from_version'], option['in_version_order'], key))

  # sort the keys

  sorted_keys.sort()

  # store only the true option

  sorted_options = []

  for key_tuple in sorted_keys:

    option_key = key_tuple[2]

    sorted_options.append(options[option_key])

  context.update(

      page_name='Update Tasks starter',

      options=sorted_options,

      )

  content = loader.render_to_string(template, dictionary=context)

  return http.HttpResponse(content)

class TaskRunner(object):

  """Runs one of the supported tasks.

  """

  STUDENT_SCHOOL_TYPE = {

      'from_version': '0-5-20090914',

      'in_version_order': 1,

      'description': ugettext(

          'Updates due to changes in the Student model. Sets all school_type '

          'entries to University since that was the first type of Student that '

          'was supported.'),

      'starter': student_school_type.startSchoolTypeUpdate,

      'runner': student_school_type.runSchoolTypeUpdate,

      }

  def __init__(self):

    """Initializes the TaskRunner.

    """

    self.options = {

        'student_school_type': self.STUDENT_SCHOOL_TYPE,

    }

  def getOptions(self):

    """Returns the supported options.

    """

    return self.options

  def startTask(self, request, option_name):

    """Starts the specified Task for the given option.

    """

    context = responses.getUniversalContext(request)

    context['page_name'] = 'Start Update Task'

    option = self.options.get(option_name)

    if not option:

      template = 'soc/error.html'

      context['message'] = 'Uknown option "%s".' % option_name

    else:

      template = 'soc/tasks/run_update.html'

      context['option'] = option

      context['success'] = option['starter'](request,

                                             self._getRunUpdateURL(option_name))

    content = loader.render_to_string(template, dictionary=context)

    return http.HttpResponse(content)

  def _getRunUpdateURL(self, option):

    """Returns the URL to run a specific update.

    Args:

      option: the update option for which the URL should returned

    """

    return '/tasks/update/run/%s' % option

  def runTask(self, request, option_name, *args, **kwargs):

    """Runs the specified Task for the given option.

    """

    option = self.options.get(option_name)

    if not option:

      error_handler('Uknown Updater option "%s".' % option_name)

    else:

      return option['runner'](request, *args, **kwargs)

task_runner = TaskRunner()

start_task = task_runner.startTask

run_task = task_runner.runTask