# -*- coding: utf-8 -*-
#
# dcolumn/common/view_mixins.py
#

"""
Dynamic Column view mixins.
"""
__docformat__ = "restructuredtext en"

import logging

from django.http import JsonResponse

log = logging.getLogger('dcolumn.common.views')


class JSONResponseMixin(object):
    """
    A mixin that can be used to render a JSON response.
    """

    def render_to_json_response(self, context, **response_kwargs):
        """
        Returns a JSON response, transforming 'context' to make the payload.

        :param context: The template rendering context.
        :type context: See `Django Context <https://docs.djangoproject.com/en/dev/ref/templates/api/#playing-with-context-objects>`_.
        :param response_kwargs: Response keywords arguments.
        :rtype: See `Django response_class <https://docs.djangoproject.com/en/dev/ref/class-based-views/mixins-simple/#django.views.generic.base.TemplateResponseMixin.response_class>`_.
        """
        return JsonResponse(self.get_data(**context), **response_kwargs)

    def get_data(self, **context):
        """
        Returns the context that will be serialized to JSON.

        .. note::
          This method must be implemented by the subclass.

        :param context: Context added to the JSON response.
        :type context: dict
        :rtype: dict -- Updated context
        """
        raise NotImplementedError(_("Must implemented 'get_data'."))


## class AjaxableResponseMixin(object):
##     """
##     Mixin to add AJAX support to a form. Must be used with an object-based
##     FormView (e.g. CreateView)
##     """

##     def form_invalid(self, form):
##         """
##         Renders the invalid form error description. See `Django's form_invalid
##         <https://docs.djangoproject.com/en/dev/ref/class-based-views/mixins-editing/#django.views.generic.edit.FormMixin.form_invalid>`_.
##         If the request is an AJAX request return this data as a JSON string.

##         :param form: The Django form object.
##         :type form: Django's form object.
##         :rtype: Result from Django's ``form_valid`` or a JSON string.
##         """
##         response = super(AjaxableResponseMixin, self).form_invalid(form)

##         if self.request.is_ajax():
##             return JsonResponse(form.errors, status=422)
##         else:
##             return response

##     def form_valid(self, form):
##         """
##         Renders the valid data. See `Django's form_valid <https://docs.djangoproject.com/en/dev/ref/class-based-views/mixins-editing/#django.views.generic.edit.FormMixin.form_valid>`_.
##         If the request is an AJAX request return this data as a JSON string.

##         :param form: The Django form object.
##         :type form: Django's form object.
##         :rtype: Result from Django's ``form_valid`` or a JSON string.
##         """
##         # We make sure to call the parent's form_valid() method because
##         # it might do some processing (in the case of CreateView, it will
##         # call form.save() for example).
##         response = super(AjaxableResponseMixin, self).form_valid(form)

##         if self.request.is_ajax():
##             return JsonResponse(self.get_data(**{}))
##         else:
##             return response

##     def get_data(self, **context):
##         """
##         Returns an object that will be serialized as JSON by json.dumps().

##         :param context: Context added to the JSON response.
##         :type context: dict
##         :rtype: dict -- Updated context
##         """
##         context.update({'pk': self.object.pk})
##         return context
