from core.builtin_concepts import BuiltinConcepts
from evaluators.BaseEvaluator import OneReturnValueEvaluator


class AddToMemoryEvaluator(OneReturnValueEvaluator):
    """
    Last chance to alter the return_value
    This evaluator is supposed to be a generic evaluator for all rules that must be executed just before
        the aggregations
    """

    NAME = "AddToMemory"

    def __init__(self):
        super().__init__(self.NAME, [BuiltinConcepts.AFTER_EVALUATION], 10)

    def matches(self, context, return_value):
        evaluation_parents = context.get_parents(lambda c: c.action == BuiltinConcepts.PROCESSING)
        if len(evaluation_parents) > 1:
            return False  # It must be executed only when the top level context

        from core.sheerka.services.SheerkaMemory import SheerkaMemory
        return len(context.sheerka.services[SheerkaMemory.NAME].registration) > 0

    def eval(self, context, return_value):
        if context.sheerka.during_initialisation:
            from core.sheerka.services.SheerkaMemory import SheerkaMemory
            service = context.sheerka.services[SheerkaMemory.NAME]
            service.registration.clear()
            return None

        context.sheerka.commit_registered_objects(context)
        return None  # no need to have a second pass