import pytest

from core.builtin_concepts import BuiltinConcepts, ReturnValueConcept
from core.concept import Concept
from evaluators.BaseEvaluator import BaseEvaluator
from evaluators.OneErrorEvaluator import OneErrorEvaluator
from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka


def r(value, status=True):
    return ReturnValueConcept(value, status, value)


def eval_false(name, value="value"):
    return ReturnValueConcept(BaseEvaluator.PREFIX + name, False, value)


reduce_requested = ReturnValueConcept("some_name", True, Concept(key=BuiltinConcepts.REDUCE_REQUESTED))


class TestOneErrorEvaluator(TestUsingMemoryBasedSheerka):
    @pytest.mark.parametrize("return_values, expected", [
        ([r("evaluators.one error", False), reduce_requested], True),
        ([r("evaluators.one error", False), r("failed", False), r("failed", False), reduce_requested], True),
        ([r("evaluators.error", False), r("not a parser in success"), reduce_requested], True),
        ([r("evaluators.no reduce required", False), r("failed", False), r("failed", False)], False),
        ([r("evaluators.no reduce required", False)], False),
        ([r("evaluators.error", False), r("evaluators.success"), reduce_requested], False),
        ([r("evaluators.error", False), r("parsers.success"), reduce_requested], False),
        ([r("evaluators.success"), r("not an evaluator in error", False), reduce_requested], False),
        ([r("evaluators.error", False), r("evaluators.another error", False), reduce_requested], False),
    ])
    def test_i_can_match(self, return_values, expected):
        context = self.get_context()
        assert OneErrorEvaluator().matches(context, return_values) == expected

    def test_i_can_eval(self):
        context = self.get_context()

        return_values = [
            r("evaluators.one error", False),
            r("parsers.failed", False),
            r("parsers.failed", False),
            reduce_requested
        ]

        evaluator = OneErrorEvaluator()
        evaluator.matches(context, return_values)
        res = evaluator.eval(context, return_values)

        assert not res.status
        assert context.sheerka.isinstance(res.body, BuiltinConcepts.RETURN_VALUE)
        assert res.body.body == "evaluators.one error"
        assert len(res.parents) == 4

    def test_unwanted_return_values_are_not_eaten(self):
        context = self.get_context()

        a_successful_concept = r("successful concept")
        a_concept_in_error = r("concept in error", False)
        return_values = [
            r("evaluators.one error", False),
            r("parsers.failed", False),
            r("parsers.failed", False),
            a_successful_concept,
            a_concept_in_error,
            reduce_requested
        ]

        evaluator = OneErrorEvaluator()
        evaluator.matches(context, return_values)
        res = evaluator.eval(context, return_values)

        assert not res.status
        assert context.sheerka.isinstance(res.body, BuiltinConcepts.RETURN_VALUE)
        assert res.body.body == "evaluators.one error"
        assert len(res.parents) == 4

        assert a_successful_concept not in res.parents
        assert a_concept_in_error not in res.parents

    def test_i_can_manage_filtered_return_values(self):
        sheerka, context = self.init_concepts()

        filtered = sheerka.new(BuiltinConcepts.FILTERED)
        filtered_ret_val = eval_false("Filter", filtered)
        false_1 = eval_false("one")

        evaluator = OneErrorEvaluator()
        return_values = [filtered_ret_val, false_1, reduce_requested]
        assert evaluator.matches(context, return_values)
        res = evaluator.eval(context, return_values)
        assert not res.status
        assert res.body.body == false_1.body
        assert res.parents == return_values

        evaluator.reset()
        return_values = [filtered_ret_val, reduce_requested]
        assert evaluator.matches(context, return_values)
        res = evaluator.eval(context, return_values)
        assert not res.status
        assert res.body.body == filtered
        assert res.parents == return_values

        evaluator.reset()
        return_values = [false_1, reduce_requested]
        assert evaluator.matches(context, return_values)
        res = evaluator.eval(context, return_values)
        assert not res.status
        assert res.body.body == false_1.body
        assert res.parents == return_values