from rest_framework import serializers
from .models import Code, Page, Element

# from datetime import datetime, timezone

from django.utils import timezone
# from zoneinfo import ZoneInfo 

# KST = ZoneInfo("Asia/Seoul")

class ElementSerializer(serializers.Serializer):
    element_id = serializers.CharField(required=False)
    element_type = serializers.CharField()
    content = serializers.CharField(allow_blank=True)
    css = serializers.DictField()

class PageSerializer(serializers.Serializer):
    cut = serializers.IntegerField()
    elements = ElementSerializer(many=True)

class CodeSerializer(serializers.Serializer):
    id = serializers.SerializerMethodField()
    pages = PageSerializer(many=True, required=False)
    created_at  = serializers.SerializerMethodField()
    updated_at  = serializers.SerializerMethodField()

    def get_created_at(self, obj):
        return timezone.localtime(obj.created_at).isoformat(timespec="seconds")

    def get_updated_at(self, obj):
        return timezone.localtime(obj.updated_at).isoformat(timespec="seconds")

    def get_id(self, obj):
        return str(obj.id)

    def create(self, validated_data):
        pages_data = validated_data.pop('pages')
        pages = [
            Page(
                cut=page['cut'],
                elements=[Element(**el) for el in page['elements']]
            ) for page in pages_data
        ]
        code = Code(pages=pages, **validated_data)
        code.save()
        return code

    def update(self, instance, validated_data):
        update_pages_data = validated_data.get('pages', [])
        existing = {p.cut: p for p in instance.pages}
        
        for page in update_pages_data:
            cut = page.get('cut')
            if cut and cut in existing:
                page_obj = existing[cut]
                page_obj.elements = [Element(**el) for el in page["elements"]]
            
            else:
                instance.pages.append(
                    Page(
                    cut=cut,
                    elements=[Element(**el) for el in page["elements"]]
                    )
                )

        instance.save()
        return instance