from django.conf import settings
from django.core.cache import cache
from django.core.paginator import Paginator
from django.db.models import Count, F, Q, Sum
from django.http import JsonResponse
from django.shortcuts import get_object_or_404, redirect
from django.urls import reverse
from django.views import View
from django.views.generic import DetailView, ListView, TemplateView

from ..models import Album, Photo, Redir


class AlbumsList(ListView):
    """Displays a paginated list of public albums."""
    model = Album
    template_name = 'gallery/album_list.html'
    paginate_by = 30

    def get_queryset(self):
        page = self.request.GET.get('page', 1)
        key = f'album_list_queryset_page_{page}'
        queryset = cache.get(key)

        if not queryset:
            queryset = (
                Album.objects.filter(is_public=True)
                .select_related('cover')
                .annotate(
                    photo_count=Count('photos'),
                    total_views=Sum('photos__views')
                )
                .order_by('-album_date')
            )
            cache.set(key, queryset, 60 * 5)

        return queryset

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        page = int(self.request.GET.get('page', 1))

        # Canonical_url
        canonical_url = self.request.build_absolute_uri(reverse('gallery:albums_url'))
        if page > 1:
            canonical_url += f'?page={page}'
        context['canonical_url'] = canonical_url

        return context


class AlbumDetail(DetailView):
    """Shows a single album and its paginated photos."""
    model = Album
    template_name = 'gallery/album_detail.html'

    def get_object(self, queryset=None):
        return get_object_or_404(Album, slug=self.kwargs.get('album_slug'))

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        # photos = self.object.photos.all().order_by('taken_at')
        photos = self.object.photos.all().select_related('album').order_by('taken_at')

        paginator = Paginator(photos, 30)
        page_obj = paginator.get_page(self.request.GET.get('page'))

        # Canonical_url
        page = int(self.request.GET.get('page', 1))
        canonical_url = self.request.build_absolute_uri(self.object.get_absolute_url())
        if page > 1:
            canonical_url += f'?page={page}'

        context.update({
            'photos': page_obj.object_list,
            'page_obj': page_obj,
            'canonical_url': canonical_url,
        })
        return context


class AlbumSearch(TemplateView):
    """Search view for public albums by name, place or city."""
    template_name = "gallery/album_search.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        query = self.request.GET.get('q', '').strip()
        context['query'] = query

        results = Album.objects.none()
        if query:
            results = Album.objects.filter(
                Q(is_public=True),
                Q(name__icontains=query) |
                Q(location__place__icontains=query) |
                Q(location__city__name__icontains=query)
            ).order_by('-album_date').distinct()

        paginator = Paginator(results, 30)
        page_obj = paginator.get_page(self.request.GET.get('page'))

        context.update({
            'results': page_obj.object_list,
            'page_obj': page_obj,
            'paginator': paginator,
            'is_paginated': page_obj.has_other_pages(),
            'canonical_url': self.request.build_absolute_uri(reverse('gallery:search_url'))
        })
        return context