from core.BuiltinConcepts import BuiltinConcepts
from core.ExecutionContext import ExecutionContext, ContextActions
from core.ReturnValue import ReturnValue
from core.error import ErrorContext
from evaluators.base_evaluator import EvaluatorEvalResult, EvaluatorMatchResult, OneReturnValueEvaluator
from services.SheerkaPython import EvaluationContext


class PythonEvaluator(OneReturnValueEvaluator):
    NAME = "PythonEvaluator"

    def __init__(self):
        super().__init__(self.NAME, ContextActions.EVALUATION, 50)

    def matches(self, context: ExecutionContext, return_value: ReturnValue) -> EvaluatorMatchResult:
        return EvaluatorMatchResult(return_value.status and
                                    context.sheerka.isinstance(return_value.value, BuiltinConcepts.PYTHON_CODE))

    def eval(self, context: ExecutionContext,
             evaluation_context: object,
             return_value: ReturnValue) -> EvaluatorEvalResult:

        sheerka = context.sheerka
        fragment = return_value.value.pf

        evaluated = sheerka.evaluate_python(context, EvaluationContext(), fragment)
        if isinstance(evaluated, ErrorContext):
            return EvaluatorEvalResult([ReturnValue(self.name, False, evaluated, parents=[return_value])],
                                       [])
        else:
            return EvaluatorEvalResult([ReturnValue(self.name, True, evaluated, parents=[return_value])],
                                       [return_value])