from api.utils.storage_service import storage_service 
from rest_framework import serializers
from .models import Vucem, CredencialesImportador




class VucemSerializer(serializers.ModelSerializer):
    importadores = serializers.SerializerMethodField()

    key = serializers.FileField(write_only=True, required=False, allow_null=True)
    cer = serializers.FileField(write_only=True, required=False, allow_null=True)
    
    key_download_url = serializers.SerializerMethodField(read_only=True)
    cer_download_url = serializers.SerializerMethodField(read_only=True)

    class Meta:
        model = Vucem
        fields = '__all__'
        read_only_fields = ('created_at', 'updated_at', 'organizacion', 'created_by', 'updated_by')
    
    def get_key_download_url(self, obj):
        if obj.key:
            return storage_service.get_file_url(obj.key)
        return None
    
    def get_cer_download_url(self, obj):
        if obj.cer:
            return storage_service.get_file_url(obj.cer)
        return None
    
    def create(self, validated_data):
        key_file = validated_data.pop('key', None)
        cer_file = validated_data.pop('cer', None)
        organizacion = validated_data.get('organizacion')
        
        vucem = super().create(validated_data)
        
        if key_file:
            ruta = storage_service.save_vucem_key(
                file=key_file,
                organizacion_id=organizacion.id,
                metadata={'vucem_id': str(vucem.id)}
            )
            if ruta:
                vucem.key = ruta
            else:
                vucem.delete()
                raise serializers.ValidationError({"key": "Error al guardar la llave"})
        
        if cer_file:
            ruta = storage_service.save_vucem_cert(
                file=cer_file,
                organizacion_id=organizacion.id,
                metadata={'vucem_id': str(vucem.id)}
            )
            if ruta:
                vucem.cer = ruta
            else:
                vucem.delete()
                raise serializers.ValidationError({"cer_file": "Error al guardar el certificado"})
        
        vucem.save()
        return vucem
    
    def update(self, instance, validated_data):
        key_file = validated_data.pop('key', None)
        cer_file = validated_data.pop('cer', None)
        organizacion = validated_data.get('organizacion', instance.organizacion)
        
        instance = super().update(instance, validated_data)
        
        if key_file:
            if instance.key:
                storage_service.delete_file(str(instance.key))
            ruta = storage_service.save_vucem_key(
                file=key_file,
                organizacion_id=organizacion.id
            )
            if ruta:
                instance.key = ruta
        
        if cer_file:
            if instance.cer:
                storage_service.delete_file(str(instance.cer))
            ruta = storage_service.save_vucem_cert(
                file=cer_file,
                organizacion_id=organizacion.id
            )
            if ruta:
                instance.cer = ruta
        
        instance.save()
        return instance
    
    def get_importadores(self, obj):
        # Importar aquí para evitar importación circular
        from api.customs.serializers import ImportadorSerializer
        return [ImportadorSerializer(cred.rfc).data for cred in obj.usuarios_importadores.all()]


class CredencialesImportadorSimpleSerializer(serializers.ModelSerializer):
    class Meta:
        model = CredencialesImportador
        fields = ('__all__')
        read_only_fields = ('updated_at',)


class CredencialesImportadorSerializer(serializers.ModelSerializer):

    class Meta:
        model = CredencialesImportador
        fields = '__all__'
        read_only_fields = ('updated_at',)

    def to_representation(self, instance):
        representation = super().to_representation(instance)
        representation['vucem'] = VucemSerializer(instance.vucem).data
        return representation