from . import models
from . import serializers
from djangochannelsrestframework import permissions
from djangochannelsrestframework.generics import GenericAsyncAPIConsumer
from djangochannelsrestframework.mixins import (
    ListModelMixin,
    PatchModelMixin,
    UpdateModelMixin,
    CreateModelMixin,
    DeleteModelMixin,
)

class LiveConsumer(ListModelMixin, GenericAsyncAPIConsumer):
    queryset = models.Test.objects.all()
    serializer_class = serializers.TestSerializer
    permission_classes = (permissions.IsAuthenticated,)

class TestConsumer(ObserverModelInstanceMixin, GenericAsyncAPIConsumer):
    queryset = get_user_model().objects.all()
    serializer_class = UserSerializer

{
    "action": "subscribe_instance",
    "pk": 42,  # the id of the instance you are subscribing to
    "request_id": 4  # this id will be used for all result updates.
}

{
  "action": "update",
  "errors": [],
  "response_status": 200,
  "request_id": 4,
  "data": {'email': '42@example.com', 'id': 42, 'username': 'thenewname'},
}

class UserConsumer(GenericAsyncAPIConsumer):
    queryset = get_user_model().objects.all()
    serializer_class = UserSerializer

    @action()
    async def send_email(self, pk=None, to=None, **kwargs):
        user = await database_sync_to_async(self.get_object)(pk=pk)
        # ... do some stuff
        # remember to wrap all db actions in `database_sync_to_async`
        return {}, 200  # return the context and the response code.

    @action()  # if the method is not async it is already wrapped in `database_sync_to_async`
    def publish(self, pk=None, **kwargs):
        user = self.get_object(pk=pk)
        # ...
        return {'pk': pk}, 200

from djangochannelsrestframework.decorators import action
from djangochannelsrestframework.consumers import AsyncAPIConsumer


class MyConsumer(AsyncAPIConsumer):

    @action()
    async def an_async_action(self, some=None, **kwargs):
        # do something async
        return {'response with': 'some message'}, 200

    @action()
    def a_sync_action(self, pk=None, **kwargs):
        # do something sync
        return {'response with': 'some message'}, 200

from djangochannelsrestframework.consumers import view_as_consumer

application = ProtocolTypeRouter({
    "websocket": AuthMiddlewareStack(
        URLRouter([
            url(r"^front(end)/$", view_as_consumer(YourDjangoView)),
        ])
    ),
 })

# signals.py
from django.dispatch.dispatcher import Signal

joined_chat_signal = Signal()

# consumers.py
from djangochannelsrestframework.consumers import AsyncAPIConsumer
from djangochannelsrestframework.decorators import action
from djangochannelsrestframework.observer import observer
from rest_framework import status
from .signals import joined_chat_signal
from .serializers import UserSerializer


class TestConsumer(AsyncAPIConsumer):

    @action()
    def join_chat(self, chat_id, **kwargs):
        serializer = UserSerializer(instance=self.scope['user'])
        joined_chat_signal.send(sender='join_chat', data=serializer.data, **kwargs)
        return {}, status.HTTP_204_NO_CONTENT

    @observer(signal=joined_chat_signal)
    async def joined_chat_handler(self, data, observer=None, action=None, subscribing_request_ids=[], **kwargs):
        for request_id in subscribing_request_ids:
            await self.reply(action='joined_chat', data=data, status=status.HTTP_200_OK, request_id=request_id)

    @joined_chat_handler.serializer
    def join_chat_handler(self, sender, data, **kwargs): # the data comes from the signal.send and will be available in the observer
        return data

    @joined_chat_handler.groups_for_signal
    def joined_chat_handler(self, instance, **kwargs):
        yield f'chat__{instance}'

    @joined_chat_handler.groups_for_consumer
    def joined_chat_handler(self, chat, **kwargs):
        if chat:
            yield f'chat__{chat}'

    @action()
    async def subscribe_joined(self, chat_id, request_id, **kwargs):
        await self.joined_chat_handler.subscribe(chat_id, request_id=request_id)

from djangochannelsrestframework.observer import model_observer

@model_observer(models.Test)
async def model_activity(self, message, observer=None, action=None, **kwargs):
    # send activity to your frontend
    await self.send_json(message)

async def websocket_connect(self, message):

    # Super Save
    await super().websocket_connect(message)

    # Initialized operation
    await self.activities_change.subscribe()

class ModelConsumerObserver(AsyncAPIConsumer):

    async def accept(self, **kwargs):
        await super().accept(** kwargs)
        await self.model_change.subscribe()

    @model_observer(models.Test)
    async def model_change(self, message, action=None, **kwargs):
        """
        This method is evaluated once for every user that subscribed,
        here you have access to info about the user by reading `self.scope`

        However it is best to avoid doing DB quires here since if you have lots of
        subscribers to a given instance you will end up with a LOT of database traffic.
        """
        await self.send_json(message)

    # If you want the data serialized instead of pk
    @model_change.serializer
    def model_serialize(self, instance, action, **kwargs):
        """
        This block is evaluated before the data is sent over the channel layer
        this means you are unable to access information
        such as the user that it will be sent to.

        If you need the user info when serializing then you can do the serialization
        in the above method.
        """
        return TestSerializer(instance).data

class ModelConsumerObserver(AsyncAPIConsumer):

    async def accept(self, **kwargs):
        await super().accept(** kwargs)
        await self.model_change.subscribe()

    @model_observer(models.Test, serializer_class=TestSerializer)
    async def model_change(self, message, action=None, **kwargs):
        # in this case since we subscribe int he `accept` method
        # we do not expect to have any `subscribing_request_ids` to loop over.
        await self.reply(data=message, action=action)

class MyConsumer(AsyncAPIConsumer):
  # This class MUST subclass `AsyncAPIConsumer` to use `@model_observer`

  @model_observer(models.Classroom)
  async def classroom_change_handler(
      self,
      message,
      observer=None,
      action=None,
      subscribing_request_ids=[],
      **kwargs
  ):
      # due to not being able to make DB QUERIES when selecting a group
      # maybe do an extra check here to be sure the user has permission
      # send activity to your frontend
      for request_id in subscribing_request_ids:
          # we can send a separate message for each subscribing request
          # this lets ws clients rout these messages.
          await self.send_json(dict(body=message, action=action, request_id=request_id))
      # note if we do not pass `request_id` to the `subscribe` method
      # then `subscribing_request_ids` will be and empty list.

  @classroom_change_handler.groups_for_signal
  def classroom_change_handler(self, instance: models.Classroom, **kwargs):
      # this block of code is called very often *DO NOT make DB QUERIES HERE*
      yield f'-school__{instance.school_id}'
      yield f'-pk__{instance.pk}'

  @classroom_change_handler.groups_for_consumer
  def classroom_change_handler(self, school=None, classroom=None, **kwargs):
      # This is called when you subscribe/unsubscribe
      if school is not None:
          yield f'-school__{school.pk}'
      if classroom is not None:
          yield f'-pk__{classroom.pk}'

  @action()
  async def subscribe_to_classrooms_in_school(self, school_pk, request_id, **kwargs):
      # check user has permission to do this
      await self.classroom_change_handler.subscribe(school=school, request_id=request_id)

  @action()
  async def subscribe_to_classroom(self, classroom_pk, request_id, **kwargs):
      # check user has permission to do this
      await self.classroom_change_handler.subscribe(classroom=classroom, request_id=request_id)