#!/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.

"""Decorators for the Task API.

"""

__authors__ = [

  '"Daniel Hans" <daniel.m.hans@gmail.com>',

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

  ]

import logging

from functools import wraps

from soc.tasks import responses as task_responses

def task(func):

  """Task decorator wrapper method

  """

  @wraps(func)

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

    """Decorator wrapper method

    """

    try:

      return func(request, *args, **kwargs)

    except task_responses.FatalTaskError, error:

      logging.exception(error)

      return task_responses.terminateTask()

    except Exception, exception:

      logging.exception(exception)

      return task_responses.repeatTask()

  return wrapper

def iterative_task(func):

  """Iterative wrapper method

  """

  @wraps(func)

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

    """Decorator wrapper method

    Params usage:

      logic: name of the logic for the data model to iterate through

      filter: a dict for the properties that the entities should have

      order: a list with the sort order

      json: json object with additional parameters

    Returns:

      Standard http django response

    """

    post_dict = request.POST

    if 'logic' not in post_dict:

       return task_responses.terminateTask()

    _temp = __import__(post_dict['logic'], globals(), locals(), ['logic'], -1)

    logic = _temp.logic

    filter = None

    if 'filter' in post_dict:

      filter = simplejson.loads(post_dict['filter'])

    order = None

    if 'order' in post_dict:

      order = simplejson.loads(post_dict['order'])

    start_key = None

    if 'next_key' in post_dict:

      start_key = db.Key(post_dict['start_key'])

    json = None

    if 'json' in post_dict:

      json = post_dict['json']

    entities, start_key = logic.getBatchOfData(filter, order, start_key)

    try:

      new_json = func(request, entities=entities, json=json, *args, **kwargs)

    except task_responses.FatalTaskError, error:

      logging.error(error)

      return task_responses.terminateTask()

    except Exception, exception:

      logging.error(exception)

      return task_responses.repeatTask()

    if start_key is None:

      logging.debug('Task sucessfully completed')

    else:

      context = post_dict.copy()

      if 'json' in context:

        del context['json']

      context.update({'start_key': start_key})

      if new_json is not None:

        context.update({'json': new_json})

      task_responses.startTask(url=request.path, context=context)

    return task_responses.terminateTask()

  return wrapper