views.py

from django.shortcuts import get_object_or_404
from django.views.generic import ListView, DetailView
from django.contrib.postgres.search import (
    SearchVector, SearchQuery, SearchRank
)
from django.views.generic.edit import FormMixin, FormView
from django.core.mail import send_mail
from django.db.models import Count
from taggit.models import Tag

from .models import Post, Comment
from .forms import CommentForm, EmailPostForm


class PostListView(ListView):
    paginate_by = 10
    template_name = 'blog/post-list.html'

    def get_queryset(self, **kwargs):
        queryset = Post.published.all()
        tag_slug = self.kwargs.get('tag_slug')
        query = self.request.GET.get('query')
        if tag_slug:
            tag = get_object_or_404(Tag, slug=tag_slug)
            queryset = queryset.filter(tags__in=[tag])
        if query:
            search_vector = SearchVector('title', weight='A') +\
                SearchVector('body', weight='B')
            search_query = SearchQuery(query)

            queryset = Post.published.annotate(
                rank=SearchRank(search_vector, search_query)
            ).filter(rank__gte=0.3).order_by('-rank')
        return queryset

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["tag"] = self.kwargs.get('tag_slug')
        context["query"] = self.request.GET.get('query')
        return context


class PostDetailView(FormMixin, DetailView):
    template_name = 'blog/post-detail.html'
    form_class = CommentForm

    def get_object(self):
        obj = get_object_or_404(Post, status='published',
                                slug=self.kwargs.get('slug'),
                                publish__year=self.kwargs.get('year'),
                                publish__month=self.kwargs.get('month'),
                                publish__day=self.kwargs.get('day')
                                )
        return obj

    def get_success_url(self):
        return self.get_object().get_absolute_url()

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        post = self.get_object()

        post_tags_ids = post.tags.values_list('id', flat=True)
        similar_posts = Post.published.filter(tags__in=post_tags_ids)\
            .exclude(id=post.id)
        similar_posts = similar_posts.annotate(same_tags=Count('tags'))\
            .order_by('-same_tags', '-publish')[:4]

        comments = Comment.objects.filter(post=post, active=True)
        context["similar_posts"] = similar_posts
        context['comments'] = comments
        context['form'] = self.get_form()
        return context

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        form = self.get_form()

        if form.is_valid():
            comment = form.save(commit=False)
            comment.post = self.get_object()
            comment.save()
            return self.form_valid(form)
        else:
            print("Invalid form")
            return self.form_invalid(form)


class PostShareView(FormView):
    form_class = EmailPostForm
    template_name = 'blog/post-share.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["post"] = get_object_or_404(
            Post, id=self.kwargs.get('post_id'))
        context["sent"] = False
        return context

    def form_valid(self, form):
        context = self.get_context_data()
        # Send Email
        cd = form.cleaned_data
        post = context['post']
        post_url = self.request.build_absolute_uri(
            post.get_absolute_url()
        )
        subject = f"{cd['name']} recommends you read {post.title}"
        message = f"Read {post.title} at {post_url}\n\n" \
            f"{cd['name']}\'s comments: {cd['comments']}"
        send_mail(subject, message, 'admin@myblog.com', [cd['to']])

        context['sent'] = True
        context['form'] = form
        return self.render_to_response(context)