''' book list views'''
from django.contrib.auth.decorators import login_required
from django.core.paginator import Paginator
from django.db.models import Q
from django.http import HttpResponseNotFound, HttpResponseBadRequest
from django.shortcuts import get_object_or_404, redirect
from django.template.response import TemplateResponse
from django.utils.decorators import method_decorator
from django.views import View
from django.views.decorators.http import require_POST

from bookwyrm import forms, models
from bookwyrm.activitypub import ActivitypubResponse
from bookwyrm.connectors import connector_manager
from .helpers import is_api_request, object_visible_to_user, privacy_filter
from .helpers import get_user_from_username

# pylint: disable=no-self-use
class Lists(View):
    ''' book list page '''
    def get(self, request):
        ''' display a book list '''
        try:
            page = int(request.GET.get('page', 1))
        except ValueError:
            page = 1

        user = request.user if request.user.is_authenticated else None
        lists = models.List.objects.filter(
            ~Q(user=user),
        ).all()
        lists = privacy_filter(request.user, lists, ['public', 'followers'])

        paginated = Paginator(lists, 12)
        data = {
            'title': 'Lists',
            'lists': paginated.page(page),
            'list_form': forms.ListForm(),
            'path': '/list',
        }
        return TemplateResponse(request, 'lists/lists.html', data)

    @method_decorator(login_required, name='dispatch')
    # pylint: disable=unused-argument
    def post(self, request):
        ''' create a book_list '''
        form = forms.ListForm(request.POST)
        if not form.is_valid():
            return redirect('lists')
        book_list = form.save()
        return redirect(book_list.local_path)

class UserLists(View):
    ''' a user's book list page '''
    def get(self, request, username):
        ''' display a book list '''
        try:
            page = int(request.GET.get('page', 1))
        except ValueError:
            page = 1
        user = get_user_from_username(username)
        lists = models.List.objects.filter(user=user).all()
        lists = privacy_filter(
            request.user, lists, ['public', 'followers', 'unlisted'])
        paginated = Paginator(lists, 12)

        data = {
            'title': '%s: Lists' % user.name,
            'user': user,
            'is_self': request.user.id == user.id,
            'lists': paginated.page(page),
            'list_form': forms.ListForm(),
            'path': user.local_path + '/lists',
        }
        return TemplateResponse(request, 'user/lists.html', data)


class List(View):
    ''' book list page '''
    def get(self, request, list_id):
        ''' display a book list '''
        book_list = get_object_or_404(models.List, id=list_id)
        if not object_visible_to_user(request.user, book_list):
            return HttpResponseNotFound()

        if is_api_request(request):
            return ActivitypubResponse(book_list.to_activity())

        query = request.GET.get('q')
        suggestions = None
        if query and request.user.is_authenticated:
            # search for books
            suggestions = connector_manager.local_search(query, raw=True)
        elif request.user.is_authenticated:
            # just suggest whatever books are nearby
            suggestions = request.user.shelfbook_set.filter(
                ~Q(book__in=book_list.books.all())
            )
            suggestions = [s.book for s in suggestions[:5]]
            if len(suggestions) < 5:
                suggestions += [
                    s.default_edition for s in \
                        models.Work.objects.filter(
                            ~Q(editions__in=book_list.books.all()),
                        ).order_by('-updated_date')
                ][:5 - len(suggestions)]


        data = {
            'title': '%s | Lists' % book_list.name,
            'list': book_list,
            'items': book_list.listitem_set.filter(approved=True),
            'pending_count': book_list.listitem_set.filter(
                approved=False).count(),
            'suggested_books': suggestions,
            'list_form': forms.ListForm(instance=book_list),
            'query': query or ''
        }
        return TemplateResponse(request, 'lists/list.html', data)


    @method_decorator(login_required, name='dispatch')
    # pylint: disable=unused-argument
    def post(self, request, list_id):
        ''' edit a book_list '''
        book_list = get_object_or_404(models.List, id=list_id)
        form = forms.ListForm(request.POST, instance=book_list)
        if not form.is_valid():
            return redirect('list', book_list.id)
        book_list = form.save()
        return redirect(book_list.local_path)


class Curate(View):
    ''' approve or discard list suggestsions '''
    @method_decorator(login_required, name='dispatch')
    def get(self, request, list_id):
        ''' display a pending list '''
        book_list = get_object_or_404(models.List, id=list_id)
        if not book_list.user == request.user:
            # only the creater can curate the list
            return HttpResponseNotFound()

        data = {
            'title': 'Curate "%s" | Lists' % book_list.name,
            'list': book_list,
            'pending': book_list.listitem_set.filter(approved=False),
            'list_form': forms.ListForm(instance=book_list),
        }
        return TemplateResponse(request, 'lists/curate.html', data)


    @method_decorator(login_required, name='dispatch')
    # pylint: disable=unused-argument
    def post(self, request, list_id):
        ''' edit a book_list '''
        book_list = get_object_or_404(models.List, id=list_id)
        suggestion = get_object_or_404(
            models.ListItem, id=request.POST.get('item'))
        approved = request.POST.get('approved') == 'true'
        if approved:
            suggestion.approved = True
            suggestion.save()
        else:
            suggestion.delete()
        return redirect('list-curate', book_list.id)


@require_POST
def add_book(request, list_id):
    ''' put a book on a list '''
    book_list = get_object_or_404(models.List, id=list_id)
    if not object_visible_to_user(request.user, book_list):
        return HttpResponseNotFound()

    book = get_object_or_404(models.Edition, id=request.POST.get('book'))
    # do you have permission to add to the list?
    if request.user == book_list.user or book_list.curation == 'open':
        # go ahead and add it
        models.ListItem.objects.create(
            book=book,
            book_list=book_list,
            added_by=request.user,
        )
    elif book_list.curation == 'curated':
        # make a pending entry
        models.ListItem.objects.create(
            approved=False,
            book=book,
            book_list=book_list,
            added_by=request.user,
        )
    else:
        # you can't add to this list, what were you THINKING
        return HttpResponseBadRequest()

    return redirect('list', list_id)


@require_POST
def remove_book(request, list_id):
    ''' put a book on a list '''
    book_list = get_object_or_404(models.List, id=list_id)
    item = get_object_or_404(models.ListItem, id=request.POST.get('item'))

    if not book_list.user == request.user and not item.added_by == request.user:
        return HttpResponseNotFound()

    item.delete()
    return redirect('list', list_id)