# -*- coding: utf-8 -*-

from django.db import models
from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
from django.core.urlresolvers import reverse
from django.utils.functional import cached_property
from django.utils.translation import ugettext as _
from wagtail.contrib.modeladmin.helpers import AdminURLHelper, ButtonHelper
from wagtail.contrib.modeladmin.options import ModelAdmin
from wagtail.contrib.modeladmin.views import IndexView
from django.utils import translation
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger

from wagtail.wagtailcore.models import Page, Orderable
from wagtail.wagtailadmin.edit_handlers import FieldPanel
from wagtail.wagtailcore.fields import RichTextField

class Stream(models.Model):
    title = models.CharField(max_length=255)
    ident = models.CharField(max_length=255)

    def __str__(self):
        return self.title

LANGUAGE_CHOICES = (
    ('de', 'Deutsch'),
    ('fr', 'Français'),
    ('it', 'Italiano'),
    ('en', 'English'),
    ('',   ' * * * '),
)

class Entry(models.Model):
    """Implementation of the Entry from the feedly API as generic Django model
    """
    raw = models.TextField(blank=True, editable=False)
    updated = models.DateTimeField(auto_now=True, editable=False)
    published = models.DateTimeField(auto_now_add=True, editable=False)
    entry_id = models.CharField(max_length=255, unique=True, blank=True, editable=False)

    title = models.CharField(max_length=255)
    author = models.CharField(max_length=255, blank=True)
    link = models.URLField()
    visual = models.URLField(blank=True)
    lang = models.CharField(max_length=2, blank=True, default='', choices=LANGUAGE_CHOICES)
    content = models.TextField()
    tags = models.TextField(blank=True)

    stream = models.ForeignKey(Stream,
        blank=True, on_delete=models.CASCADE,
        verbose_name='Original stream')

    class Meta:
        verbose_name_plural = 'Entries'

# Button
class ExportButtonHelper(ButtonHelper):
    """
    This helper constructs all the necessary attributes to create a button.

    There is a lot of boilerplate just for the classnames to be right :(
    """

    export_button_classnames = ['icon', 'icon-download']

    def export_button(self, classnames_add=None, classnames_exclude=None):
        if classnames_add is None:
            classnames_add = []
        if classnames_exclude is None:
            classnames_exclude = []

        classnames = self.export_button_classnames + classnames_add
        cn = self.finalise_classname(classnames, classnames_exclude)
        text = _('Export {}'.format(self.verbose_name_plural.title()))

        return {
            'url': self.url_helper.get_action_url('export', query_params=self.request.GET),
            'label': text,
            'classname': cn,
            'title': text,
        }


class ExportAdminURLHelper(AdminURLHelper):
    """
    This helper constructs the different urls.

    This is mostly just to overwrite the default behaviour
    which consider any action other than 'create', 'choose_parent' and 'index'
    as `object specific` and will try to add the object PK to the url
    which is not what we want for the `export` option.

    In addition, it appends the filters to the action.
    """

    non_object_specific_actions = ('create', 'choose_parent', 'index', 'export')

    def get_action_url(self, action, *args, **kwargs):
        query_params = kwargs.pop('query_params', None)

        url_name = self.get_action_url_name(action)
        if action in self.non_object_specific_actions:
            url = reverse(url_name)
        else:
            url = reverse(url_name, args=args, kwargs=kwargs)

        if query_params:
            url += '?{params}'.format(params=query_params.urlencode())

        return url

    def get_action_url_pattern(self, action):
        if action in self.non_object_specific_actions:
            return self._get_action_url_pattern(action)

        return self._get_object_specific_action_url_pattern(action)


class ExportView(IndexView):
    """
    A Class Based View which will generate
    """

    def export_csv(self):
        data = self.queryset.all()
        response = ...
        return response


    @method_decorator(login_required)
    def dispatch(self, request, *args, **kwargs):
        super().dispatch(request, *args, **kwargs)
        return self.export_csv()


class ExportModelAdminMixin(object):
    """
    A mixin to add to your model admin which hooks the different helpers, the view
    and register the new urls.
    """

    button_helper_class = ExportButtonHelper
    url_helper_class = ExportAdminURLHelper

    export_view_class = ExportView

    def get_admin_urls_for_registration(self):
        urls = super().get_admin_urls_for_registration()
        urls += (
            url(
                self.url_helper.get_action_url_pattern('export'),
                self.export_view,
                name=self.url_helper.get_action_url_name('export')
            ),
        )

        return urls

    def export_view(self, request):
        kwargs = {'model_admin': self}
        view_class = self.export_view_class
        return view_class.as_view(**kwargs)(request)


class MenuModelAdmin(ExportModelAdminMixin, ModelAdmin):
    model = Entry

class FeedPage(Page):
    intro = RichTextField(default='', blank=True)
    stream = models.ForeignKey(Stream, on_delete=models.PROTECT,
        null=True, blank=True, verbose_name='Filter to stream (optional)')

    content_panels = [
        FieldPanel('title'),
        FieldPanel('intro'),
        FieldPanel('stream'),
    ]

    @property
    def feedentries(self):
        if self.stream:
            entries = Entry.objects.filter(stream=self.stream)
        else:
            entries = Entry.objects.all()
        # Filter out by chosen language
        curlang = translation.get_language()
        if curlang in ['de']:
            entries = entries.exclude(lang='fr')
        elif curlang in ['fr']:
            entries = entries.exclude(lang='de')
        # Order by most recent date first
        return entries.order_by('-published')[:72]

    def get_context(self, request):
        # Update template context
        context = super(FeedPage, self).get_context(request)

        # Wrap with pagination
        paginator = Paginator(self.feedentries, 9)
        page = request.GET.get('page')
        try:
            feedentries = paginator.page(page)
        except (PageNotAnInteger, EmptyPage):
            feedentries = paginator.page(1)

        context['feedentries'] = feedentries
        return context

    class Meta:
        verbose_name = "Feeds"