from django.shortcuts import get_object_or_404
from django.utils.translation import gettext as _

from ...acl.objectacl import add_acl_to_obj
from ...categories import PRIVATE_THREADS_ROOT_NAME, THREADS_ROOT_NAME
from ...categories.models import Category
from ...core.shortcuts import validate_slug
from ...core.viewmodel import ViewModel as BaseViewModel
from ...readtracker.threadstracker import make_read_aware
from ..models import Poll, Thread
from ..participants import make_participants_aware
from ..permissions import (
    allow_see_private_thread,
    allow_see_thread,
    allow_use_private_threads,
)
from ..serializers import PrivateThreadSerializer, ThreadSerializer
from ..subscriptions import make_subscription_aware
from ..threadtypes import trees_map

__all__ = ["ForumThread", "PrivateThread"]

BASE_RELATIONS = [
    "category",
    "poll",
    "starter",
    "starter__rank",
    "starter__ban_cache",
    "starter__online_tracker",
]


class ViewModel(BaseViewModel):
    def __init__(
        self,
        request,
        pk,
        slug=None,
        path_aware=False,
        read_aware=False,
        subscription_aware=False,
        poll_votes_aware=False,
    ):
        model = self.get_thread(request, pk, slug)

        if path_aware:
            model.path = self.get_thread_path(model.category)

        add_acl_to_obj(request.user_acl, model.category)
        add_acl_to_obj(request.user_acl, model)

        if read_aware:
            make_read_aware(request.user, request.user_acl, model)
        if subscription_aware:
            make_subscription_aware(request.user, model)

        self._model = model

        try:
            self._poll = model.poll
            add_acl_to_obj(request.user_acl, self._poll)

            if poll_votes_aware:
                self._poll.make_choices_votes_aware(request.user)
        except Poll.DoesNotExist:
            self._poll = None

    @property
    def poll(self):
        return self._poll

    def get_thread(self, request, pk, slug=None):
        raise NotImplementedError(
            "Thread view model has to implement get_thread(request, pk, slug=None)"
        )

    def get_thread_path(self, category):
        thread_path = []

        if category.level:
            categories = Category.objects.filter(
                tree_id=category.tree_id, lft__lte=category.lft, rght__gte=category.rght
            ).order_by("level")
            thread_path = list(categories)
        else:
            thread_path = [category]

        thread_path[0].name = self.get_root_name()
        return thread_path

    def get_root_name(self):
        raise NotImplementedError("Thread view model has to implement get_root_name()")

    def get_frontend_context(self):
        raise NotImplementedError(
            "Thread view model has to implement get_frontend_context()"
        )

    def get_template_context(self):
        return {
            "thread": self._model,
            "poll": self._poll,
            "category": self._model.category,
            "breadcrumbs": self._model.path,
        }


class ForumThread(ViewModel):
    def get_thread(self, request, pk, slug=None):
        thread = get_object_or_404(
            Thread.objects.select_related(*BASE_RELATIONS),
            pk=pk,
            category__tree_id=trees_map.get_tree_id_for_root(THREADS_ROOT_NAME),
        )

        allow_see_thread(request.user_acl, thread)
        if slug:
            validate_slug(thread, slug)
        return thread

    def get_root_name(self):
        return _("Threads")

    def get_frontend_context(self):
        return ThreadSerializer(self._model).data


class PrivateThread(ViewModel):
    def get_thread(self, request, pk, slug=None):
        allow_use_private_threads(request.user_acl)

        thread = get_object_or_404(
            Thread.objects.select_related(*BASE_RELATIONS),
            pk=pk,
            category__tree_id=trees_map.get_tree_id_for_root(PRIVATE_THREADS_ROOT_NAME),
        )

        make_participants_aware(request.user, thread)
        allow_see_private_thread(request.user_acl, thread)

        if slug:
            validate_slug(thread, slug)

        return thread

    def get_root_name(self):
        return _("Private threads")

    def get_frontend_context(self):
        return PrivateThreadSerializer(self._model).data