@login_required
def post_edit(request, username, post_id):
    template_name = "posts/new_post.html"
    post = get_object_or_404(Post, pk=post_id, author__username=username)
    url = reverse(
        "post_single",
        kwargs={"username": username, "post_id": post_id}
    )
    if post.author != request.user:
        return redirect(url)

    form = PostForm(
        request.POST or None,
        files=request.FILES or None,
        instance=post
    )

    if request.POST and form.is_valid():
        form.save()
        return redirect(url)

    labels = {
        "title": "Редактировать запись",
        "button": "Сохранить"
    }

    return render(
        request,
        template_name,
        {
            "form": form,
            "labels": labels,
            "post": post
        }
    )