text: from django.views.generic import ListView
  from django.shortcuts import render, get_object_or_404
  from django.core.mail import send_mail
  from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
  from django.db.models import Count
  
  from taggit.models import Tag
  
  from .models import Post
  from .forms import EmailPostForm, CommentForm, SubscriberForm
  
  
  # class PostListView(ListView):
  #     queryset = Post.published.all()
  #     context_object_name = 'posts'
  #     paginate_by = 3
  #     template_name = 'blog/post/list.html'
  
  
  def post_list(request, tag_slug=None):
      object_list = Post.published.all()
      tag = None
  
      if tag_slug:
          tag = get_object_or_404(Tag, slug=tag_slug)
          object_list = object_list.filter(tags__in=[tag])
  
      paginator = Paginator(object_list, 3)
      page = request.GET.get('page')
      try:
          posts = paginator.page(page)
      except PageNotAnInteger:
          posts = paginator.page(1)
      except EmptyPage:
          posts = paginator.page(paginator.num_pages)
      return render(request,
                    'blog/post/list.html',
                    {'page': page,
                     'posts': posts,
                     'tag': tag})
  
  
  def post_detail(request, year, month, day, post):
      post = get_object_or_404(
          Post,
          slug=post,
          status='published',
          publish__year=year,
          publish__month=month,
          publish__day=day,
      )
      comments = post.comments.filter(active=True)
      new_comment = None
  
      if request.method == 'POST':
          comment_form = CommentForm(data=request.POST)
          if comment_form.is_valid():
              new_comment = comment_form.save(commit=False)
              new_comment.post = post
              new_comment.save()
              comment_form = CommentForm()
      else:
          comment_form = CommentForm()
  
      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]
  
      return render(
          request,
          'blog/post/detail.html',
          {
              'post': post,
              'comments': comments,
              'comment_form': comment_form,
              'new_comment': new_comment,
              'similar_posts': similar_posts,
          },
      )
  
  
  def post_share(request, post_id):
      post = get_object_or_404(Post, id=post_id, status='published')
      sent = False
  
      if request.method == 'POST':
          form = EmailPostForm(request.POST)
          if form.is_valid():
              cd = form.cleaned_data
              post_url = request.build_absolute_uri(post.get_absolute_url())
              subject = '{} ({}) zachęca do przeczytania "{}"'.format(
                  cd['name'], cd['email'], post.title
              )
              message = 'Przeczytaj post "{}" na stronie {}\n\n Komentarz dodany przez {}: {}'.format(
                  post.title, post_url, cd['name'], cd['comments']
              )
              send_mail(subject, message, 'admin@myblog.com', [cd['to']])
              sent = True
      else:
          form = EmailPostForm()
      return render(request, 'blog/post/share.html', {'post': post, 'form': form, 'sent': sent})
  
  
  def subscribe_view(request):
      subscribed = False
      if request.method == 'POST':
          form = SubscriberForm(request.POST)
          if form.is_valid():
              form.save()
              subscribed = True
      return render(request, 'blog/post/subscribed.html', {'subscribed': subscribed,})
  
  