from django import forms
from django.db import models
from modelcluster.fields import ParentalKey, ParentalManyToManyField
from modelcluster.contrib.taggit import ClusterTaggableManager
from taggit.models import TaggedItemBase

from wagtail.models import Page, Orderable
from wagtail.fields import RichTextField, StreamField
from wagtail.admin.panels import FieldPanel, InlinePanel, MultiFieldPanel
from wagtail.search import index

from wagtail.snippets.models import register_snippet

from blog.blocks import BlogPostBlock
from wagtailseo.models import SeoMixin, SeoType

class BlogIndexPage(SeoMixin, Page):
    intro = RichTextField(blank=True)

    def get_context(self, request):
        # Update context to include only published posts, ordered by reverse-chron
        context = super().get_context(request)
        blogpages = self.get_children().live().order_by('-first_published_at')
        context['blogpages'] = blogpages
        return context

    content_panels = Page.content_panels + [
        FieldPanel('intro')
    ]
    promote_panels = SeoMixin.seo_panels

class BlogTagIndexPage(Page):

    def get_context(self, request):
        tag = request.GET.get('tag')
        blogpages = BlogPage.objects.filter(tags__name=tag)

        # Update template context
        context = super().get_context(request)
        context['blogpages'] = blogpages
        return context

class BlogPageTag(TaggedItemBase):
    content_object = ParentalKey(
        'BlogPage',
        related_name='tagged_items',
        on_delete=models.CASCADE
    )

class BlogPage(SeoMixin, Page):
    date = models.DateField("Post date")
    intro = models.TextField()
    body = StreamField(
        BlogPostBlock(),
        blank=True,
        use_json_field=True,
        help_text="Write anything",
    )

    authors = ParentalManyToManyField('blog.Author', blank=True)

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

    def main_image(self):
        gallery_item = self.gallery_images.first()
        if gallery_item:
            return gallery_item.image
        else:
            return None

    search_fields = Page.search_fields + [
        index.SearchField('intro'),
        index.SearchField('body'),
    ]

    content_panels = Page.content_panels + [
        MultiFieldPanel([
            FieldPanel('date'),
            FieldPanel('authors', widget=forms.CheckboxSelectMultiple),
            FieldPanel('tags'),
        ], heading="Blog information"),
        FieldPanel('intro'),
        FieldPanel('body'),
        InlinePanel('gallery_images', label="Gallery images"),
    ]

    promote_panels = SeoMixin.seo_panels
    seo_content_type = SeoType.ARTICLE


class BlogPageGalleryImage(Orderable):
    page = ParentalKey(BlogPage, on_delete=models.CASCADE, related_name='gallery_images')
    image = models.ForeignKey(
        'wagtailimages.Image', on_delete=models.CASCADE, related_name='+'
    )
    caption = models.CharField(blank=True, max_length=250)

    panels = [
        FieldPanel('image'),
        FieldPanel('caption'),
    ]

@register_snippet
class Author(models.Model):
    name = models.CharField(max_length=255)
    author_image = models.ForeignKey(
        'wagtailimages.Image', null=True, blank=True,
        on_delete=models.SET_NULL, related_name='+'
    )

    panels = [
        FieldPanel('name'),
        FieldPanel('author_image'),
    ]

    def __str__(self):
        return self.name

    class Meta:
        verbose_name_plural = 'Authors'