import typing
from marshmallow import ValidationError

class InputValidationBase:
    """
    Base class for input validators. Common validation methods are grouped here.
    """

    @staticmethod
    def check_required_fields(content:dict, required_fields:list[str]):
        missing_fields = [field for field in required_fields if content.get(field) is None]
        if missing_fields:
            raise ValidationError({"required_fields": f"Missing required fields: {missing_fields}"})

    @staticmethod
    def check_if_entry_is_already_deleted(entry:dict):
        """
        Checks if the entry has 'deleted' set to True/1.
        """
        if entry.get("deleted") in [True, 1, "1"]:
            raise ValidationError({"deleted": "The selected entry is already deleted."})

    @staticmethod
    def check_deleted_flag_on_post(content:dict):
        """
        Checks if 'deleted' is set to 1/True in a POST (Create) request.
        """
        if content.get("deleted") in [True, 1, "1"]:
            raise ValidationError({"deleted": "Cannot create an entry with 'deleted' set to 1."})