from vbv_lernwelt.competence.serializers import PerformanceCriteriaLearningPathSerializer
from vbv_lernwelt.learnpath.models import LearningUnit
from vbv_lernwelt.learnpath.serializer_helpers import get_it_serializer_class


class LearningUnitSerializer(get_it_serializer_class(LearningUnit, [
    'id', 'title', 'slug', 'type', 'translation_key',
    'course_category', 'children',
])):
    def get_children(self, obj):
        return [
            PerformanceCriteriaLearningPathSerializer(child).data
            for child in obj.performancecriteria_set.all()
        ]