from django.core.paginator import Paginator
from django.shortcuts import render, get_object_or_404, redirect
from django.contrib.auth.decorators import login_required
from django.contrib.auth import get_user_model
from .models import Post, Group
from .forms import PostForm

User = get_user_model()


def index(request):
    post_list = Post.objects.all().order_by('-id')
    paginator = Paginator(post_list, 10)
    # Из URL извлекаем номер запрошенной страницы - это значение параметра page
    page_number = request.GET.get('page')
    # Получаем набор записей для страницы с запрошенным номером
    page = paginator.get_page(page_number)
    return render(request, 'index.html', {'page': page, })


def group_posts(request, slug):
    group = get_object_or_404(Group, slug=slug)
    posts = group.posts.all()
    # Показывать по 10 записей на странице.
    paginator = Paginator(posts, 10)
    # Из URL извлекаем номер запрошенной страницы - это значение параметра page
    page_number = request.GET.get('page')
    # Получаем набор записей для страницы с запрошенным номером
    page = paginator.get_page(page_number)
    return render(request, "group.html", {"group": group, "page": page})


@login_required
def new_post(request):
    form = PostForm(request.POST or None)
    if not form.is_valid():
        return render(request,
                      'new.html', {'form': form,
                                   'but': 'Добавить', })
    else:
        post = form.save(commit=False)
        post.author = request.user
        post.save()
        return redirect('index')
    return render(request,
                  'new.html', {'form': form,
                               'but': 'Добавить', })


def profile(request, username):
    user_prof = get_object_or_404(User, username=username)
    post_list = user_prof.posts.all()
    paginator = Paginator(post_list, 10)
    page_number = request.GET.get('page')
    page = paginator.get_page(page_number)
    return render(request, 'profile.html', {'author': user_prof,
                                            'page': page, })


def post_view(request, username, post_id):
    post = get_object_or_404(Post, author__username=username, pk=post_id)
    return render(request, 'post.html',
                  {'author': post.author,
                   'post': post})


@login_required
def post_edit(request, username, post_id):
    text_post = get_object_or_404(Post, pk=post_id, author__username=username)
    if text_post.author != request.user:
        return redirect('post', username=username,
                        post_id=post_id)
    form = PostForm(request.POST or None, files=request.FILES or None,
                    instance=text_post)
    if not form.is_valid():
        return render(request,
                      'new.html', {'form': form,
                                   'but': 'Редактировать', })
    post = form.save(commit=False)
    post.save()
    return redirect('post', username=username,
                    post_id=post.id)
    return render(request,
                  'new.html', {'form': form,
                               'but': 'Редактировать',
                               'lab': 'Редактировать запись', })


def page_not_found(request, exception):
    return render(
        request,
        "misc/404.html",
        {"path": request.path},
        status=404
    )


def server_error(request):
    return render(request, "misc/500.html", status=500)