# -*- encoding: utf-8 -*-

import logging

from django.db.models import Q
from django_filters import rest_framework as rest_filters
from rest_framework import permissions, filters, generics, status
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination
from rest_framework.authentication import SessionAuthentication, TokenAuthentication
from rest_framework.parsers import MultiPartParser, FormParser
from rest_framework.filters import BaseFilterBackend

from apps.home.models import (
    Server,
    ContentFilter,
    MessageMutator,
    MessageStyle,
    Subscription,
    Content,
    SubscriptionRecommendation
)
from apps.authentication.models import DiscordUser, ServerMember
from .metadata import ExpandedMetadata
from .serializers import (
    ServerSerializer,
    ContentFilterSerializer,
    MessageMutatorSerializer,
    MessageStyleSerializer,
    SubscriptionSerializer,
    ContentSerializer,
    SubscriptionRecommendationSerializer
)
from .permissions import HasServerAccess
from .errors import NotAMemberError

log = logging.getLogger(__name__)


class DefaultPagination(PageNumberPagination):
    """Default class for pagination in API views."""

    page_size = 10
    page_query_param = "page"
    page_size_query_param = "page_size"
    max_page_size = 25


def is_automated_admin(user):
    return user.user_type == DiscordUser.USER_TYPES.AUTOMATED_USER and user.is_superuser


class ListView(generics.ListAPIView):
    authentication_classes = [SessionAuthentication, TokenAuthentication]
    permission_classes = [permissions.IsAuthenticated]
    pagination_class = DefaultPagination
    metadata_class = ExpandedMetadata
    filter_backends = [filters.SearchFilter, rest_filters.DjangoFilterBackend, filters.OrderingFilter]


class ListCreateView(generics.ListCreateAPIView):
    authentication_classes = [SessionAuthentication, TokenAuthentication]
    permission_classes = [permissions.IsAuthenticated]
    pagination_class = DefaultPagination
    metadata_class = ExpandedMetadata
    filter_backends = [filters.SearchFilter, rest_filters.DjangoFilterBackend, filters.OrderingFilter]


class DetailView(generics.RetrieveAPIView):
    authentication_classes = [SessionAuthentication, TokenAuthentication]
    permission_classes = [permissions.IsAuthenticated]
    parser_classes = [MultiPartParser, FormParser]


class ChangableDetailView(generics.RetrieveUpdateDestroyAPIView):
    authentication_classes = [SessionAuthentication, TokenAuthentication]
    permission_classes = [permissions.IsAuthenticated]
    parser_classes = [MultiPartParser, FormParser]


class DeletableDetailView(generics.RetrieveDestroyAPIView):
    authentication_classes = [SessionAuthentication, TokenAuthentication]
    permission_classes = [permissions.IsAuthenticated]
    parser_classes = [MultiPartParser, FormParser]


# region Servers

class Server_ListView(ListView):
    filterset_fields = ("id", "name", "icon_hash", "active")
    search_fields = ("name")
    ordering_fields = ("id", "name", "active")
    serializer_class = ServerSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return Server.objects.all().order_by("id")

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        return Server.objects.filter(id__in=servers).order_by("id")


class Server_DetailView(DeletableDetailView):
    serializer_class = ServerSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return Server.objects.all()

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        return Server.objects.filter(id__in=servers)

    def destroy(self, request, *args, **kwargs):
        server = self.get_object()

        if not self.request.user.is_superuser:
            member = ServerMember.objects.get(server=server, user=request.user)
            if not member.is_owner:
                return Response(
                    {"detail": "Only the owner can destroy server data."},
                    status=status.HTTP_403_FORBIDDEN
                )

        return super().destroy(request, *args, **kwargs)


# region Filters

class ContentFilter_ListView(ListCreateView):
    filterset_fields = ("id", "server", "name", "match", "matching_algorithm", "is_insensitive", "is_whitelist")
    search_fields = ("name", "match")
    ordering_fields = ("id", "server", "name", "match", "matching_algorithm", "is_insensitive", "is_whitelist")
    serializer_class = ContentFilterSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return ContentFilter.objects.all().order_by("name")

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        return ContentFilter.objects.filter(server__in=servers).order_by("name")


class ContentFilter_DetailView(ChangableDetailView):
    serializer_class = ContentFilterSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return ContentFilter.objects.all()

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        return ContentFilter.objects.filter(server__in=servers)


# region Mutators

class MessageMutator_ListView(ListView):  # instances of this one are pre-defined ONLY
    filterset_fields = ("id", "name", "value")
    search_fields = ("name", "value")
    ordering_fields = ("id", "name", "value")
    serializer_class = MessageMutatorSerializer

    def get_queryset(self):
        return MessageMutator.objects.all()


class MessageMutator_DetailView(DetailView):
    serializer_class = MessageMutatorSerializer

    def get_queryset(self):
        return MessageMutator.objects.all()


# Message Styles

class MessageStyle_ListView(ListCreateView):
    filterset_fields = ("id", "server", "name", "is_embed", "is_hyperlinked", "show_author", "show_timestamp", "show_images", "fetch_images", "title_mutator", "description_mutator")
    search_fields = ("name",)
    ordering_fields = ("id", "server", "name", "is_embed", "is_hyperlinked", "show_author", "show_timestamp", "show_images", "fetch_images")
    serializer_class = MessageStyleSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return MessageStyle.objects.all().order_by("id")

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        return MessageStyle.objects.filter(server__in=servers).order_by("id")


class MessageStyle_DetailView(ChangableDetailView):
    serializer_class = MessageStyleSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return MessageStyle.objects.all()

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        return MessageStyle.objects.filter(server__in=servers)


# region Subscriptions

class Subscription_ListView(ListCreateView):
    filterset_fields = ("id", "server", "name", "url", "created_at", "updated_at", "extra_notes", "active", "publish_threshold", "filters", "message_style")
    search_fields = ("name", "url", "extra_notes")
    ordering_fields = ("id", "server", "name", "url", "created_at", "updated_at", "extra_notes", "active", "message_style")
    serializer_class = SubscriptionSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return Subscription.objects.all().order_by("id")

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        return Subscription.objects.filter(server__in=servers).order_by("id")


class Subscription_DetailView(ChangableDetailView):
    serializer_class = SubscriptionSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return Subscription.objects.all()

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        return Subscription.objects.filter(server__in=servers)


# region Content


class ContentFilterBackend(BaseFilterBackend):
    """
    If `match_any=true` in querystring, matches 'any' params instead
    of 'all' params.
    """

    _MATCH_ANY_PARAM = "match_any"
    _IGNORE_PARAMS = [
        DefaultPagination.page_query_param,
        DefaultPagination.page_size_query_param,
        "search",
        "subscription"
    ]

    def filter_queryset(self, request, queryset, view):
        filters = Q()
        match_any = request.query_params.get(self._MATCH_ANY_PARAM, "").lower() == "true"
        log.debug(f"matching any against content: {match_any}")

        for param, value in request.query_params.items():
            if param in self._IGNORE_PARAMS or param == self._MATCH_ANY_PARAM:
                continue

            query = Q(**{param: value})

            if match_any:
                filters |= query
            else:
                filters &= query

            log.debug(query)

        queryset_filter = queryset.filter(filters)
        log.debug(queryset_filter.query)
        return queryset_filter


class Content_ListView(ListCreateView):
    search_fields = (
        "item_id",
        "item_guid",
        "item_url",
        "item_title",
        "item_description",
        "item_content_hash",
        "item_image_url",
        "item_thumbnail_url",
        "item_published",
        "item_author",
        "item_author_url",
        "item_feed_title",
        "item_feed_url"
    )
    filterset_fields = search_fields + ("id", "subscription", "subscription__server")
    ordering_fields = filterset_fields
    serializer_class = ContentSerializer
    filter_backends = [
        ContentFilterBackend,
        filters.SearchFilter,
        rest_filters.DjangoFilterBackend,
        filters.OrderingFilter
    ]

    def get_queryset(self):
        if self.request.user.is_superuser:
            return Content.objects.all().order_by("-subscription__created_at", "id")

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        subscriptions = Subscription.objects.filter(server__in=servers).values_list("id", flat=True)
        return Content.objects.filter(subscription__in=subscriptions).order_by("-subscription__created_at", "id")


class Content_DetailView(ChangableDetailView):
    serializer_class = ContentSerializer

    def get_queryset(self):
        if self.request.user.is_superuser:
            return Content.objects.all()

        servers = ServerMember.objects.filter(user=self.request.user).values_list("server", flat=True)
        subscriptions = Subscription.objects.filter(server__in=servers).values_list("id", flat=True)
        return Content.objects.filter(subscription__in=subscriptions)


# region Sub Recommendations

class SubscriptionRecommendations_ListView(ListView):
    queryset = SubscriptionRecommendation.objects.all().order_by("id")
    serializer_class = SubscriptionRecommendationSerializer