# ~*~ coding: utf-8 ~*~
from collections import defaultdict

from django.utils.translation import ugettext as _
from rest_framework.decorators import action
from rest_framework import generics
from rest_framework.response import Response
from rest_framework_bulk import BulkModelViewSet

from common.api import CommonApiMixin
from common.utils import get_logger
from common.api import SuggestionMixin
from orgs.utils import current_org, tmp_to_root_org
from rbac.models import Role, RoleBinding
from users.utils import LoginBlockUtil, MFABlockUtils
from .mixins import UserQuerysetMixin
from ..notifications import ResetMFAMsg
from .. import serializers
from ..serializers import (
    UserSerializer,
    MiniUserSerializer, InviteSerializer
)
from ..models import User
from ..signals import post_user_create
from ..filters import UserFilter

logger = get_logger(__name__)
__all__ = [
    'UserViewSet', 'UserChangePasswordApi',
    'UserUnblockPKApi', 'UserResetMFAApi',
]


class UserViewSet(CommonApiMixin, UserQuerysetMixin, SuggestionMixin, BulkModelViewSet):
    filterset_class = UserFilter
    search_fields = ('username', 'email', 'name')
    serializer_classes = {
        'default': UserSerializer,
        'suggestion': MiniUserSerializer,
        'invite': InviteSerializer,
    }
    ordering_fields = ('name',)
    ordering = ('name',)
    rbac_perms = {
        'match': 'users.match_user',
        'invite': 'users.invite_user',
        'remove': 'users.remove_user',
        'bulk_remove': 'users.remove_user',
    }

    def get_queryset(self):
        queryset = super().get_queryset().prefetch_related('groups')
        return queryset

    def paginate_queryset(self, queryset):
        page = super().paginate_queryset(queryset)

        if page:
            page = self.set_users_roles_for_cache(page)
        else:
            self.set_users_roles_for_cache(queryset)
        return page

    @action(methods=['get'], detail=False, url_path='suggestions')
    def match(self, request, *args, **kwargs):
        with tmp_to_root_org():
            return super().match(request, *args, **kwargs)

    @staticmethod
    def set_users_roles_for_cache(queryset):
        # Todo: 未来有机会用 SQL 实现
        queryset_list = queryset
        user_ids = [u.id for u in queryset_list]
        role_bindings = RoleBinding.objects.filter(user__in=user_ids) \
            .values('user_id', 'role_id', 'scope')

        role_mapper = {r.id: r for r in Role.objects.all()}
        user_org_role_mapper = defaultdict(set)
        user_system_role_mapper = defaultdict(set)

        for binding in role_bindings:
            role_id = binding['role_id']
            user_id = binding['user_id']
            if binding['scope'] == RoleBinding.Scope.system:
                user_system_role_mapper[user_id].add(role_mapper[role_id])
            else:
                user_org_role_mapper[user_id].add(role_mapper[role_id])

        for u in queryset_list:
            system_roles = user_system_role_mapper[u.id]
            org_roles = user_org_role_mapper[u.id]
            u.org_roles.cache_set(org_roles)
            u.system_roles.cache_set(system_roles)
        return queryset_list

    def perform_create(self, serializer):
        users = serializer.save()
        if isinstance(users, User):
            users = [users]
        self.send_created_signal(users)

    def perform_bulk_update(self, serializer):
        user_ids = [
            d.get("id") or d.get("pk") for d in serializer.validated_data
        ]
        users = current_org.get_members().filter(id__in=user_ids)
        for user in users:
            self.check_object_permissions(self.request, user)
        return super().perform_bulk_update(serializer)

    def allow_bulk_destroy(self, qs, filtered):
        return filtered.count() < qs.count()

    def perform_bulk_destroy(self, objects):
        for obj in objects:
            self.check_object_permissions(self.request, obj)
            self.perform_destroy(obj)

    @action(methods=['post'], detail=False)
    def invite(self, request):
        if not current_org or current_org.is_root():
            error = {"error": "Not a valid org"}
            return Response(error, status=400)

        serializer_cls = self.get_serializer_class()
        serializer = serializer_cls(data=request.data)
        serializer.is_valid(raise_exception=True)
        validated_data = serializer.validated_data

        users = validated_data['users']
        org_roles = validated_data['org_roles']
        for user in users:
            user.org_roles.set(org_roles)
        return Response(serializer.data, status=201)

    @action(methods=['post'], detail=True)
    def remove(self, request, *args, **kwargs):
        instance = self.get_object()
        instance.remove()
        return Response(status=204)

    @action(methods=['post'], detail=False, url_path='remove')
    def bulk_remove(self, request, *args, **kwargs):
        qs = self.get_queryset()
        filtered = self.filter_queryset(qs)

        for instance in filtered:
            instance.remove()
        return Response(status=204)

    def send_created_signal(self, users):
        if not isinstance(users, list):
            users = [users]
        for user in users:
            post_user_create.send(self.__class__, user=user)


class UserChangePasswordApi(UserQuerysetMixin, generics.UpdateAPIView):
    serializer_class = serializers.ChangeUserPasswordSerializer

    def perform_update(self, serializer):
        user = self.get_object()
        user.password_raw = serializer.validated_data["password"]
        user.save()


class UserUnblockPKApi(UserQuerysetMixin, generics.UpdateAPIView):
    serializer_class = serializers.UserSerializer

    def perform_update(self, serializer):
        user = self.get_object()
        username = user.username if user else ''
        LoginBlockUtil.unblock_user(username)
        MFABlockUtils.unblock_user(username)


class UserResetMFAApi(UserQuerysetMixin, generics.RetrieveAPIView):
    serializer_class = serializers.ResetOTPSerializer

    def retrieve(self, request, *args, **kwargs):
        user = self.get_object() if kwargs.get('pk') else request.user
        if user == request.user:
            msg = _("Could not reset self otp, use profile reset instead")
            return Response({"error": msg}, status=400)

        backends = user.active_mfa_backends_mapper
        for backend in backends.values():
            if backend.can_disable():
                backend.disable()

        ResetMFAMsg(user).publish_async()
        return Response({"msg": "success"})