from django.urls import reverse
from django.shortcuts import render

from boards import settings
from boards.abstracts.constants import PARAM_PAGE
from boards.abstracts.paginator import get_paginator
from boards.abstracts.settingsmanager import get_settings_manager
from boards.models import Post
from boards.settings import SECTION_VIEW
from boards.views.base import BaseBoardView
from boards.views.mixins import PaginatedMixin

POSTS_PER_PAGE = settings.get_int(SECTION_VIEW, 'PostsPerPage')

PARAMETER_POSTS = 'posts'
PARAMETER_QUERIES = 'queries'

TEMPLATE = 'boards/feed.html'
DEFAULT_PAGE = 1


class FeedFilter:
    @staticmethod
    def get_filtered_posts(request, posts):
        return posts

    @staticmethod
    def get_query(request):
        return None


class TripcodeFilter(FeedFilter):
    @staticmethod
    def get_filtered_posts(request, posts):
        filtered_posts = posts
        tripcode = request.GET.get('tripcode', None)
        if tripcode:
            filtered_posts = filtered_posts.filter(tripcode=tripcode)
        return filtered_posts

    @staticmethod
    def get_query(request):
        tripcode = request.GET.get('tripcode', None)
        if tripcode:
            return 'Tripcode: {}'.format(tripcode)


class FavoritesFilter(FeedFilter):
    @staticmethod
    def get_filtered_posts(request, posts):
        filtered_posts = posts

        favorites = 'favorites' in request.GET
        if favorites:
            settings_manager = get_settings_manager(request)
            last_posts = settings_manager.get_last_posts()
            threads = [post.get_thread() for post in last_posts]
            filtered_posts = filtered_posts.filter(thread__in=threads)
        return filtered_posts


class IpFilter(FeedFilter):
    @staticmethod
    def get_filtered_posts(request, posts):
        filtered_posts = posts

        ip = request.GET.get('ip', None)
        if ip and request.user.has_perm('post_delete'):
            filtered_posts = filtered_posts.filter(poster_ip=ip)
        return filtered_posts

    @staticmethod
    def get_query(request):
        ip = request.GET.get('ip', None)
        if ip:
            return 'IP: {}'.format(ip)


class ImageFilter(FeedFilter):
    @staticmethod
    def get_filtered_posts(request, posts):
        filtered_posts = posts

        image = request.GET.get('image', None)
        if image:
            filtered_posts = filtered_posts.filter(attachments__file=image)
        return filtered_posts

    @staticmethod
    def get_query(request):
        image = request.GET.get('image', None)
        if image:
            return 'File: {}'.format(image)


class FeedView(PaginatedMixin, BaseBoardView):
    filters = (
            TripcodeFilter,
            FavoritesFilter,
            IpFilter,
            ImageFilter,
    )

    def get(self, request):
        page = request.GET.get(PARAM_PAGE, DEFAULT_PAGE)

        params = self.get_context_data(request=request)

        settings_manager = get_settings_manager(request)

        posts = Post.objects.exclude(
            thread__tags__in=settings_manager.get_hidden_tags()).order_by(
            '-pub_time').prefetch_related('attachments', 'thread')
        queries = []
        for filter in self.filters:
            posts = filter.get_filtered_posts(request, posts)
            query = filter.get_query(request)
            if query:
                queries.append(query)
        params[PARAMETER_QUERIES] = queries

        paginator = get_paginator(posts, POSTS_PER_PAGE,
                                  link=reverse('feed'),
                                  params=request.GET.dict())
        paginator.current_page = int(page)

        params[PARAMETER_POSTS] = paginator.page(page).object_list

        params.update(self.get_page_context(paginator, page))

        return render(request, TEMPLATE, params)