from __future__ import unicode_literals

from django.db import models
from django.shortcuts import get_list_or_404, get_object_or_404, render

from modelcluster.fields import ParentalKey
from modelcluster.contrib.taggit import ClusterTaggableManager

from taggit.models import Tag, TaggedItemBase

from wagtail.contrib.wagtailroutablepage.models import RoutablePageMixin, route
from wagtail.wagtailadmin.edit_handlers import (
    FieldPanel,
    InlinePanel,
    StreamFieldPanel,
)
from wagtail.wagtailimages.edit_handlers import ImageChooserPanel
from wagtail.wagtailcore.fields import StreamField
from wagtail.wagtailcore.models import Page, Orderable
from wagtail.wagtailsnippets.edit_handlers import SnippetChooserPanel


from bakerydemo.base.blocks import BaseStreamBlock


class BlogPeopleRelationship(Orderable, models.Model):
    '''
    This defines the relationship between the `Peopole` within the `base`
    app and the BlogPage below allowing us to add people to a BlogPage.
    '''
    page = ParentalKey(
        'BlogPage', related_name='blog_person_relationship'
    )
    people = models.ForeignKey(
        'base.People', related_name='person_blog_relationship'
    )
    panels = [
        SnippetChooserPanel('people')
    ]


class BlogPageTag(TaggedItemBase):
    content_object = ParentalKey('BlogPage', related_name='tagged_items')


class BlogPage(Page):
    '''
    A Blog Page (Post)
    '''
    image = models.ForeignKey(
        'wagtailimages.Image',
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name='+',
        help_text='Location image'
    )

    tags = ClusterTaggableManager(through=BlogPageTag, blank=True)

    date_published = models.DateField("Date article published", blank=True, null=True)

    body = StreamField(
        BaseStreamBlock(), verbose_name="Blog post", blank=True
    )

    content_panels = Page.content_panels + [
        ImageChooserPanel('image'),
        StreamFieldPanel('body'),
        FieldPanel('date_published'),
        InlinePanel(
            'blog_person_relationship', label="Author(s)",
            panels=None, min_num=1),
        FieldPanel('tags'),
    ]

    def authors(self):
        '''
        Returns the BlogPage's related People
        '''
        authors = [
            n.people for n in self.blog_person_relationship.all()
        ]

        return authors

    @property
    def get_tags(self):
        '''
        Returns the BlogPage's related list of Tags.
        Each Tag is modified to include a url attribute
        '''
        tags = self.tags.all()
        for tag in tags:
            tag.url = '/'+'/'.join(s.strip('/') for s in [
                self.get_parent().url,
                'tags',
                tag.slug
            ])
        return tags

    @property
    def blog_index(self):
        return self.get_ancestors().type(BlogIndexPage).last()

    def get_absolute_url(self):
        return self.full_url

    parent_page_types = ['BlogIndexPage']

    # Defining what content type can sit under the parent
    # The empty array means that no children can be placed under the
    # LocationPage page model
    subpage_types = []

    # api_fields = ['image', 'body']


class BlogIndexPage(RoutablePageMixin, Page):
    '''
    Index page for blogs.
    We need to alter the page model's context to return the child page objects - the
    BlogPage - so that it works as an index page

    The RoutablePageMixin is used to allow for a custom sub-URL
    '''
    image = models.ForeignKey(
        'wagtailimages.Image',
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name='+',
        help_text='Location listing image'
    )

    introduction = models.TextField(
        help_text='Text to describe the index page',
        blank=True)

    content_panels = Page.content_panels + [
        ImageChooserPanel('image'),
        FieldPanel('introduction')
    ]

    # parent_page_types = [
    #     'home.HomePage'
    # ]

    # Defining what content type can sit under the parent. Since it's a blank
    # array no subpage can be added
    subpage_types = ['BlogPage']

    def get_context(self, request):
        context = super(BlogIndexPage, self).get_context(request)
        context['blogs'] = BlogPage.objects.descendant_of(
            self).live().order_by(
            '-first_published_at')
        return context

    @route('^tags/(\w+)/$', name='tag_archive')
    def tag_archive(self, request, tag=None):
        '''
        A Custom view that utilizes Tags. This view will
        return all related BlogPages for a given Tag.
        '''
        tag = get_object_or_404(Tag, slug=tag)
        blogs = get_list_or_404(
            BlogPage.objects.filter(tags=tag).live().descendant_of(self)
        )

        context = {
            'title': 'Posts tagged with: {}'.format(tag.name),
            'blogs': blogs
        }
        return render(request, 'blog/blog_index_page.html', context)

    # api_fields = ['introduction']