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


class PrepareEvalBodyEvaluator(OneReturnValueEvaluator):
    """
    To recognize when the user input is an (body) evaluation
    """

    NAME = "PrepareEvalBody"

    def __init__(self, **kwargs):
        super().__init__(self.NAME, [BuiltinConcepts.BEFORE_PARSING], 90)
        self.text = None

    def matches(self, context, return_value):
        if not (return_value.status and
                context.sheerka.isinstance(return_value.body, BuiltinConcepts.USER_INPUT) and
                isinstance(return_value.body.body, str)):
            return False

        text = return_value.body.body.strip()
        if not text.startswith("eval "):
            return False

        self.text = text
        return True

    def eval(self, context, return_value):
        sheerka = context.sheerka

        new_text_to_parse = sheerka.ret(
            self.name,
            True, sheerka.new(BuiltinConcepts.USER_INPUT, body=self.text[5:], user_name=context.event.user_id))

        root = context.get_parents(lambda ec: ec.action == BuiltinConcepts.PROCESS_INPUT)
        root = root[0] if root else context
        root.protected_hints.add(BuiltinConcepts.EVAL_BODY_REQUESTED)
        root.protected_hints.add(BuiltinConcepts.EVAL_WHERE_REQUESTED)
        root.protected_hints.add(BuiltinConcepts.RETURN_BODY_REQUESTED)

        return new_text_to_parse