from rest_framework import serializers
from apps.certificate.models import Certificate
from apps.course.serializers import CourseDetailSerializer



class CertificateSerializer(serializers.ModelSerializer):
    course = serializers.SerializerMethodField()
    
    class Meta:
        model = Certificate
        fields = ['id', 'student', 'course', 'status', 'created_at', 'updated_at',]
        read_only_fields = ['id', 'student', 'status', 'created_at', 'updated_at',]

    def get_course(self, obj):
        return CourseDetailSerializer(obj.course, context=self.context).data




class CertificateRequestSerializer(serializers.ModelSerializer):
    class Meta:
        model = Certificate
        fields = ['id', 'course']
        read_only_fields = ['id']

    def create(self, validated_data):
        user = self.context['request'].user
        course = validated_data['course']

        if Certificate.objects.filter(student=user, course=course, status__in=['pending', 'approved']).exists():
            raise serializers.ValidationError({"course": "Passwords do not match."})
        return Certificate.objects.create(student=user, course=course)