from tastypie import fields
from tastypie.authorization import DjangoAuthorization
from tastypie.resources import ModelResource
from django_images.models import Thumbnail

from pinry.core.models import User
from pinry.pins.models import Image, Pin


class UserResource(ModelResource):
    gravatar = fields.CharField(readonly=True)

    def dehydrate_gravatar(self, bundle):
        return bundle.obj.gravatar

    class Meta:
        list_allowed_methods = ['get']
        queryset = User.objects.all()
        resource_name = 'user'
        fields = ['username']
        include_resource_uri = False


def filter_generator_for(size):
    def wrapped_func(bundle, **kwargs):
        return Thumbnail.objects.get_or_create_at_size(bundle.obj.pk, size, **kwargs)
    return wrapped_func


class ThumbnailResource(ModelResource):
    class Meta:
        list_allowed_methods = ['get']
        fields = ['image', 'width', 'height']
        queryset = Thumbnail.objects.all()
        resource_name = 'thumbnail'
        include_resource_uri = False


class ImageResource(ModelResource):
    standard = fields.ToOneField(ThumbnailResource, full=True,
                                 attribute=lambda bundle: filter_generator_for('standard')(bundle))
    thumbnail = fields.ToOneField(ThumbnailResource, full=True,
                                  attribute=lambda bundle: filter_generator_for('thumbnail')(bundle))

    class Meta:
        fields = ['image', 'width', 'height']
        include_resource_uri = False
        resource_name = 'image'
        queryset = Image.objects.all()
        authorization = DjangoAuthorization()


class PinResource(ModelResource):
    submitter = fields.ToOneField(UserResource, 'submitter', full=True)
    image = fields.ToOneField(ImageResource, 'image', full=True)
    tags = fields.ListField()

    def hydrate_image(self, bundle):
        url = bundle.data.get('url', None)
        if url:
            image = Image.objects.create_for_url(url)
            bundle.data['image'] = '/api/v1/image/{}/'.format(image.pk)
        return bundle

    def dehydrate_tags(self, bundle):
        return map(str, bundle.obj.tags.all())

    def build_filters(self, filters=None):
        if filters is None:
            filters = {}
        orm_filters = super(PinResource, self).build_filters(filters)
        if 'tag' in filters:
            orm_filters['tags__name__in'] = filters['tag'].split(',')
        return orm_filters

    def save_m2m(self, bundle):
        tags = bundle.data.get('tags', [])
        bundle.obj.tags.set(*tags)
        return super(PinResource, self).save_m2m(bundle)

    class Meta:
        fields = ['id', 'url', 'description']
        ordering = ['id']
        queryset = Pin.objects.all()
        resource_name = 'pin'
        include_resource_uri = False
        always_return_data = True
        authorization = DjangoAuthorization()