import graphene
from django.core.exceptions import PermissionDenied
from graphene import relay
from graphql_relay import to_global_id

from api.utils import get_object
from rooms.inputs import UpdateRoomArgument, AddRoomArgument, AddRoomEntryArgument, UpdateRoomEntryArgument
from rooms.models import Room, RoomEntry
from rooms.schema import RoomNode, RoomEntryNode
from rooms.serializers import RoomSerializer, RoomEntrySerializer
from users.models import SchoolClass


class MutateRoom(relay.ClientIDMutation):
    errors = graphene.List(graphene.String)
    room = graphene.Field(RoomNode)

    @classmethod
    def mutate_and_get_payload(cls, *args, **kwargs):
        room_data = kwargs.get('room')
        school_class = get_object(SchoolClass, room_data.get('school_class').get('id'))
        room_data['school_class'] = school_class.id
        if room_data.get('id') is not None:
            room = get_object(Room, room_data['id'])
            serializer = RoomSerializer(room, data=room_data)
        else:
            serializer = RoomSerializer(data=room_data)
        if serializer.is_valid():
            serializer.save()
            return cls(room=serializer.instance, errors=None)

        return cls(room=None, errors=['{}: {}'.format(key, value) for key, value in serializer.errors.items()])


class AddRoom(MutateRoom):
    class Input:
        room = graphene.Argument(AddRoomArgument)  # NB: can't be named AddRoomInput, otherwise graphene complains

    @classmethod
    def mutate_and_get_payload(cls, root, info, **kwargs):

        if not info.context.user.has_perm('users.can_manage_school_class_content'):
            return cls(room=None, errors=['not allowed'])

        room_data = kwargs.get('room')
        room_data['school_class'] = get_object(SchoolClass, room_data.get('school_class').id).id
        serializer = RoomSerializer(data=room_data)
        if serializer.is_valid():
            serializer.save()
            return cls(room=serializer.instance)

        return cls(room=None, errors=['{}: {}'.format(key, value) for key, value in serializer.errors.items()])


class UpdateRoom(MutateRoom):
    class Input:
        room = graphene.Argument(UpdateRoomArgument)  # NB: can't be named ChangeRoomInput, otherwise graphene complains


class DeleteRoom(relay.ClientIDMutation):
    class Input:
        id = graphene.ID(required=True)

    success = graphene.Boolean()
    errors = graphene.List(graphene.String)

    @classmethod
    def mutate_and_get_payload(cls, root, info, **kwargs):
        id = kwargs.get('id')
        room = get_object(Room, id)
        user = info.context.user
        if not user.has_perm('users.can_manage_school_class_content'):
            raise PermissionDenied('Missing permissions')
        if room.school_class not in user.school_classes.all():
            raise PermissionDenied('Permission denied: Incorrect school classes')
        room.delete()
        return cls(success=True)


class MutateRoomEntry(relay.ClientIDMutation):
    room_entry = graphene.Field(RoomEntryNode)
    errors = graphene.List(graphene.String)

    @classmethod
    def mutate_and_get_payload(cls, root, info, **kwargs):
        room_entry_data = kwargs.get('room_entry')

        if room_entry_data.get('room') is not None:
            room_entry_data['room'] = get_object(Room, room_entry_data.get('room')).id

        if room_entry_data.get('id') is not None:
            # update path
            instance = get_object(RoomEntry, room_entry_data.get('id'))

            if not instance.room.school_class.is_user_in_schoolclass(info.context.user):
                raise Exception('You are in the wrong class')

            if instance.author.pk != info.context.user.pk:
                raise Exception('You are not the author')

            serializer = RoomEntrySerializer(instance, data=room_entry_data, partial=True)
        else:
            # add path
            room_entry_data['author'] = info.context.user.pk
            serializer = RoomEntrySerializer(data=room_entry_data)

        if serializer.is_valid():
            serializer.save()

            return cls(room_entry=serializer.instance)

        return cls(room_entry=None, errors=['{}: {}'.format(key, value) for key, value in serializer.errors.items()])


class AddRoomEntry(MutateRoomEntry):
    class Input:
        room_entry = graphene.Argument(AddRoomEntryArgument)


class UpdateRoomEntry(MutateRoomEntry):
    class Input:
        room_entry = graphene.Argument(UpdateRoomEntryArgument)


class DeleteRoomEntry(relay.ClientIDMutation):
    class Input:
        id = graphene.ID(required=True)

    success = graphene.Boolean()
    room_slug = graphene.String()
    room_id = graphene.ID()
    errors = graphene.List(graphene.String)

    @classmethod
    def mutate_and_get_payload(cls, root, info, **kwargs):
        id = kwargs.get('id')
        room_entry = get_object(RoomEntry, id)
        if room_entry.author.pk != info.context.user.pk:
            raise Exception('You are not the owner of this room entry')
        room_id = to_global_id('RoomNode', room_entry.room.pk)
        room_slug = room_entry.room.slug
        room_entry.delete()
        return cls(success=True, room_id=room_id, room_slug=room_slug)


class RoomMutations:
    update_room = UpdateRoom.Field()
    add_room = AddRoom.Field()
    delete_room = DeleteRoom.Field()
    add_room_entry = AddRoomEntry.Field()
    delete_room_entry = DeleteRoomEntry.Field()
    update_room_entry = UpdateRoomEntry.Field()