from auto_labeling_pipeline.models import RequestModelFactory
from rest_framework import serializers

from .models import AutoLabelingConfig


class AutoLabelingConfigSerializer(serializers.ModelSerializer):

    class Meta:
        model = AutoLabelingConfig
        fields = ('id', 'model_name', 'model_attrs', 'template', 'label_mapping', 'default', 'task_type')
        read_only_fields = ('created_at', 'updated_at')

    def validate_model_name(self, value):
        try:
            RequestModelFactory.find(value)
        except NameError:
            raise serializers.ValidationError(f'The specified model name {value} does not exist.')
        return value

    def valid_label_mapping(self, value):
        if isinstance(value, dict):
            return value
        else:
            raise serializers.ValidationError(f'The {value} is not a dictionary. Please specify it as a dictionary.')

    def validate(self, data):
        try:
            RequestModelFactory.create(data['model_name'], data['model_attrs'])
        except Exception:
            model = RequestModelFactory.find(data['model_name'])
            schema = model.schema()
            required_fields = ', '.join(schema['required']) if 'required' in schema else ''
            raise serializers.ValidationError(
                'The attributes does not match the model.'
                'You need to correctly specify the required fields: {}'.format(required_fields)
            )
        return data