from core.builtin_concepts import BuiltinConcepts
from evaluators.BaseEvaluator import AllReturnValuesEvaluator
import logging

from parsers.BaseParser import BaseParser

log = logging.getLogger(__name__)


class OneSuccessEvaluator(AllReturnValuesEvaluator):
    """
    Used to filter the responses
    It has a low priority to let other evaluators try to resolve the errors

    Make sure that there is only one successful answer
    """

    NAME = "OneSuccess"

    def __init__(self):
        super().__init__(self.NAME, 10)
        self.successful_return_value = None

    def matches(self, context, return_values):
        sheerka = context.sheerka
        after_evaluation = False
        nb_successful_evaluators = 0
        only_parsers = True
        for ret in return_values:
            if sheerka.isinstance(ret.value, BuiltinConcepts.AFTER_EVALUATION):
                if ret.status:
                    after_evaluation = True
            elif ret.who.startswith(self.PREFIX):
                if ret.status:
                    nb_successful_evaluators += 1
                    self.successful_return_value = ret
            else:
                if not ret.who.startswith(BaseParser.PREFIX):
                    only_parsers = False

        return after_evaluation and nb_successful_evaluators == 1 and only_parsers

    def eval(self, context, return_values):
        sheerka = context.sheerka
        return sheerka.ret(self.name, True, self.successful_return_value.value, parents=return_values)