from datetime import datetime
from marshmallow import pre_dump
from marshmallow.exceptions import MarshmallowError


class MissingContextError(MarshmallowError):
    pass


class IsEntryBlueDotMixin:
    """Update is_entry field by a Blue Dot logic

    For usage put "utc_now": datetime.utcnow().date() to schema context!
    """

    @pre_dump
    def blue_dot(self, data, *args, **kwargs):
        result = False

        last_added_date_time = data.get("last_added_date_time")
        is_entry = data["is_entry"]
        if last_added_date_time:
            if not self.context.get("utc_now"):
                raise MissingContextError("Missing utc_now in schema context")
            result = is_entry and datetime.fromisoformat(last_added_date_time[:19]).date() == self.context["utc_now"]

        data["is_entry"] = result
        return data