from rest_framework import serializers

from vbv_lernwelt.competence.models import PerformanceCriteria
from vbv_lernwelt.course.serializers import CourseCategorySerializer
from vbv_lernwelt.learnpath.models import LearningUnit
from vbv_lernwelt.learnpath.serializer_helpers import get_it_serializer_class


class PerformanceCriteriaSerializer(get_it_serializer_class(PerformanceCriteria, [
    'id', 'title', 'slug', 'type', 'translation_key',
    'competence_id', 'learning_unit', 'circle', 'course_category',
])):
    learning_unit = serializers.SerializerMethodField()
    circle = serializers.SerializerMethodField()
    course_category = serializers.SerializerMethodField()

    def get_learning_unit(self, obj):
        learning_unit_serializer = get_it_serializer_class(LearningUnit, [
            'id', 'title', 'slug', 'type', 'translation_key',
        ])
        return learning_unit_serializer(obj.learning_unit).data

    def get_circle(self, obj):
        return obj.learning_unit.get_parent().specific.title

    def get_course_category(self, obj):
        if obj.learning_unit:
            return CourseCategorySerializer(obj.learning_unit.course_category).data
        return None


class PerformanceCriteriaLearningPathSerializer(get_it_serializer_class(PerformanceCriteria, [
    'id', 'title', 'slug', 'type', 'translation_key', 'competence_id',
])):
    pass