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


class PostExecutionEvaluator(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 = "PostExecution"

    def __init__(self):
        super().__init__(self.NAME, [BuiltinConcepts.AFTER_EVALUATION], 90)

    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

        # only support the rule for the COMMANDS
        value = return_value.body
        return isinstance(value, Concept) and context.sheerka.isa(value, context.sheerka.new(BuiltinConcepts.AUTO_EVAL))

    def eval(self, context, return_value):
        # only support the rule for the COMMANDS
        #body = return_value.body.body
        body = context.sheerka.objvalue(return_value)
        return context.sheerka.ret(
            self.name,
            True,
            body if body != BuiltinConcepts.NOT_INITIALIZED else return_value.body,
            parents=[return_value])