from django.conf import settings
from django.core.validators import MinValueValidator, MaxValueValidator
from rest_framework import serializers
from sorl.thumbnail.parsers import parse_crop
from sorl.thumbnail.parsers import ThumbnailParseError

from . import models


class ImageSerializer(serializers.ModelSerializer):
    """Serializer for model Image."""
    # REQUEST
    file = serializers.ImageField(source='image',
                                  write_only=True)
    width = serializers.IntegerField(write_only=True, required=False)
    height = serializers.IntegerField(write_only=True, required=False)
    margin = serializers.CharField(write_only=True, allow_null=True,
                                   required=False,
                                   default='center')
    quality = serializers.IntegerField(write_only=True, allow_null=True, required=False,
                                       default=settings.THUMBNAIL_QUALITY,
                                       validators=[
                                           MinValueValidator(1),
                                           MaxValueValidator(100)])

    # RESPONSE
    url = serializers.ImageField(source='image',
                                 read_only=True)
    cropped_image = serializers.DictField(read_only=True, allow_null=True)
    orientation_display = serializers.CharField(source='get_orientation_display',
                                                read_only=True)

    class Meta:
        """Meta class"""
        model = models.Image
        fields = [
            'id',
            'file',
            'url',
            'orientation',
            'orientation_display',
            'title',
            'width',
            'height',
            'margin',
            'quality',
            'cropped_image',
        ]
        extra_kwargs = {
            'orientation': {'write_only': True}
        }

    def validate(self, attrs):
        """Overridden validate method."""
        image = attrs.get('image').image
        crop_width = attrs.get('width')
        crop_height = attrs.get('height')
        margin = attrs.get('margin')

        if crop_height and crop_width and margin:
            xy_image = (image.width, image.width)
            xy_window = (crop_width, crop_height)
            try:
                parse_crop(margin, xy_image, xy_window)
            except ThumbnailParseError:
                raise serializers.ValidationError({'margin': 'Unrecognized crop option: %s' % margin})
        return attrs

    def create(self, validated_data):
        """Overridden create method."""
        width = validated_data.pop('width', None)
        height = validated_data.pop('height', None)
        quality = validated_data.pop('quality')
        margin = validated_data.pop('margin')

        instance = super().create(validated_data)

        if instance and width and height:
            setattr(instance,
                    'cropped_image',
                    instance.get_cropped_image(
                        geometry=f'{width}x{height}',
                        quality=quality,
                        margin=margin))
        return instance