"""Utils app serializer."""
from django.core import exceptions
from rest_framework import serializers
from utils import models
from translation.models import Language


class EmptySerializer(serializers.Serializer):
    """Empty Serializer"""


class SourceSerializerMixin(serializers.Serializer):
    """Base authorization serializer mixin"""
    source = serializers.ChoiceField(choices=models.PlatformMixin.SOURCES,
                                     default=models.PlatformMixin.WEB,
                                     write_only=True)


class TranslatedField(serializers.CharField):
    """Translated field."""

    def __init__(self, allow_null=True, required=False, read_only=True,
                 **kwargs):
        super().__init__(allow_null=allow_null, required=required,
                         read_only=read_only, **kwargs)


# todo: view validation in more detail
def validate_tjson(value):
    if not isinstance(value, dict):
        raise exceptions.ValidationError(
            'invalid_json',
            code='invalid_json',
            params={'value': value},
        )
    lang_count = Language.objects.filter(locale__in=value.keys()).count()
    if lang_count != len(value.keys()):
        raise exceptions.ValidationError(
            'invalid_translated_keys',
            code='invalid_translated_keys',
            params={'value': value},
        )


class TJSONField(serializers.JSONField):
    """Custom serializer's JSONField for model's TJSONField."""

    validators = [validate_tjson]


class ProjectModelSerializer(serializers.ModelSerializer):
    """Overrided ModelSerializer."""

    serializers.ModelSerializer.serializer_field_mapping[models.TJSONField] = TJSONField