from django.conf import settings
from django.db.transaction import on_commit
from rest_framework import generics, status
from rest_framework.permissions import AllowAny
from rest_framework.response import Response

from utils.methods import get_permission_classes
from utils.permissions import IsContentPageManager, IsCountryAdmin, IsEstablishmentManager, \
    IsProducerFoodInspector, IsEstablishmentAdministrator
from . import tasks, models, serializers


class ImageBaseView(generics.GenericAPIView):
    """Base Image view."""
    model = models.Image
    queryset = models.Image.objects.all()
    serializer_class = serializers.ImageSerializer
    permission_classes = get_permission_classes(
        IsContentPageManager
    )


class ImageListCreateView(ImageBaseView, generics.ListCreateAPIView):
    """
    ## List/Create view
    ### *GET*
    #### Description
    Get paginated list of images, with ordering by field `modified` (descending)
    #### Response
    E.g.:
    ```
    {
      "count": 40595,
      "next": 2,
      "previous": null,
      "results": [
        {
          "id": 47336,
          ...
        }
      ]
    }
    ```
    ### *POST*
    #### Description
    Upload an image on a server.
    ##### Request
    Required:
    * file (`file`) - download file
    Available:
    * orientation (`enum`) - default: `null`
    ```
    0 (Horizontal)
    1 (Vertical)
    ```
    * title (`str`) - title of image file (default - `''`)
    * is_public (`bool`) - flag that responds for availability
    for displaying (default - `True`)
    * preview (`file`) - download preview file (default - `null`)
    * link (`str`) - mp4 or youtube video link (default - `null`)
    * order (`int`) - order number (default - `0`)
    ##### Response
    E.g.:
    ```
    {
      "id": 47336,
      ...
    }

    ```
    """


class MediaForEstablishmentView(ImageBaseView, generics.ListCreateAPIView):
    """View for creating and retrieving certain establishment media."""
    pagination_class = None
    # permission_classes = (IsCountryAdmin, IsEstablishmentAdministrator, IsEstablishmentManager, IsProducerFoodInspector)
    permission_classes = (AllowAny, )
    serializer_class = serializers.EstablishmentGallerySerializer

    def get_queryset(self):
        return super().get_queryset().filter(establishment__pk=self.kwargs['establishment_id'])\
            .order_by('-establishment_gallery__is_main', '-order').prefetch_related('created_by',
                                                                                    'establishment_gallery')


class MediaUpdateView(ImageBaseView, generics.UpdateAPIView, generics.DestroyAPIView):
    """View for updating media data"""
    serializer_class = serializers.EstablishmentGallerySerializer
    # permission_classes = (IsCountryAdmin, IsEstablishmentAdministrator, IsEstablishmentManager, IsProducerFoodInspector)
    permission_classes = (AllowAny, )

    def delete(self, request, *args, **kwargs):
        """Override destroy view"""
        instance = self.get_object()
        if settings.USE_CELERY:
            on_commit(lambda: tasks.delete_image.delay(image_id=instance.id))
        else:
            on_commit(lambda: tasks.delete_image(image_id=instance.id))
        return Response(status=status.HTTP_204_NO_CONTENT)


class ImageRetrieveDestroyView(ImageBaseView, generics.RetrieveDestroyAPIView):
    """
    ## Retrieve/Destroy view.
    ### *GET*
    #### Description
    Retrieve serialized instance of Image model by image identifier.
    #### Response
    E.g.:
    ```
    {
        "id": 1,
        ...
    }
    ```
    ### *DELETE*
    #### Description
    Delete an image (DB record and storage object) by image identifier.
    ##### Response
    ```
    No content
    ```
    """

    def delete(self, request, *args, **kwargs):
        """Override destroy view"""
        instance = self.get_object()
        if settings.USE_CELERY:
            on_commit(lambda: tasks.delete_image.delay(image_id=instance.id))
        else:
            on_commit(lambda: tasks.delete_image(image_id=instance.id))
        return Response(status=status.HTTP_204_NO_CONTENT)


class CropImageCreateView(ImageBaseView, generics.CreateAPIView):
    """
    ## Create view
    ### *POST*
    #### Description
    Create crop of an existing image by an identifier of image and parameters in request data.
    ##### Request
    Required
    * width (`int`) - width of cropped image
    * height (`int`) - height of cropped image
    * crop (`str`) - crop coordinates (e.g.: `100px 200px`)

    Non-required
    * quality (`int`) - image quality, by default - `settings.THUMBNAIL_QUALITY` (85%)
    * certain_aspect (`str`) - certain aspect, by default -
    ```
    (x2 - x1)
        x
    (y2 - y1)
    ```
    > where x, y is coordinates parsed from `crop` parameter
    ##### Response
    E.g.:
    ```
    {
        "id": 1,
        ...
    }
    ```
    """

    serializer_class = serializers.CropImageSerializer