from rest_framework import serializers

from courses.models import Course, Vertex, Topic


class TopicSerializer(serializers.ModelSerializer):
    class Meta:
        model = Topic
        exclude = ['id']


class MiniVertexSerializer(serializers.ModelSerializer):
    object = serializers.SerializerMethodField()
    type = serializers.SerializerMethodField()

    class Meta:
        model = Vertex
        fields = ('id', 'title', 'type', 'object', 'free')

    @staticmethod
    def get_object(self):
        if self.content_type.model == 'topic':
            return TopicSerializer(self.content_object).data
        return False

    @staticmethod
    def get_type(self):
        return self.content_type.model


class VertexSerializer(MiniVertexSerializer):
    class Meta:
        model = Vertex
        fields = '__all__'


class CourseInitSerializer(serializers.ModelSerializer):

    class Meta:
        model = Course
        fields = ['title', 'slug']


class CourseListSerializer(serializers.ModelSerializer):
    statistic = serializers.SerializerMethodField()
    level = serializers.SerializerMethodField()
    direction = serializers.SerializerMethodField()

    class Meta:
        model = Course
        fields = ['id', 'title', 'statistic', 'public', 'hidden',
                  'level', 'direction', 'image', 'slug']

    @staticmethod
    def get_statistic(self):
        return self.get_statistic()

    @staticmethod
    def get_level(self):
        return self.get_level_display()

    @staticmethod
    def get_direction(self):
        return self.get_direction_display()


class CourseDetailSerializer(serializers.ModelSerializer):
    level = serializers.SerializerMethodField()
    direction = serializers.SerializerMethodField()
    teachers = serializers.SerializerMethodField()

    class Meta:
        model = Course
        fields = '__all__'

    @staticmethod
    def get_level(self):
        return self.get_level_display()

    @staticmethod
    def get_direction(self):
        return self.get_direction_display()

    @staticmethod
    def get_teachers(self):
        return [teacher.email for teacher in self.teachers.all()]