from rest_framework import serializers

from .models import FormulaDocument, FormulaRevision


class FormulaDocumentSerializer(serializers.ModelSerializer):
    class Meta:
        model = FormulaDocument
        fields = ("id", "title", "source", "created_at", "updated_at")
        read_only_fields = ("id", "created_at", "updated_at")

    def validate_source(self, value):
        if len(value) > 50_000:
            raise serializers.ValidationError("公式源码不能超过 50000 个字符")
        return value

    def create(self, validated_data):
        document = FormulaDocument.objects.create(
            user=self.context["request"].user,
            **validated_data,
        )
        FormulaRevision.objects.create(document=document, source=document.source)
        return document

    def update(self, instance, validated_data):
        instance = super().update(instance, validated_data)
        FormulaRevision.objects.create(document=instance, source=instance.source)
        return instance