import pytest
from core.builtin_concepts import ReturnValueConcept, ParserResultConcept, BuiltinConcepts
from core.concept import Concept, ConceptParts
from evaluators.ConceptEvaluator import ConceptEvaluator

from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka


class TestAddConceptEvaluator(TestUsingMemoryBasedSheerka):

    @pytest.mark.parametrize("ret_val, expected", [
        (ReturnValueConcept("some_name", True, ParserResultConcept(value=Concept())), True),
        (ReturnValueConcept("some_name", False, ParserResultConcept(value=Concept())), False),
        (ReturnValueConcept("some_name", True, ParserResultConcept(value="Not a concept")), False),
        (ReturnValueConcept("some_name", True, Concept()), False),
    ])
    def test_i_can_match(self, ret_val, expected):
        context = self.get_context()
        assert ConceptEvaluator().matches(context, ret_val) == expected

    def test_i_can_evaluate_concept(self):
        context = self.get_context()
        context.protected_hints.update({BuiltinConcepts.EVAL_BODY_REQUESTED, BuiltinConcepts.EVAL_WHERE_REQUESTED})
        concept = Concept(name="foo",
                          where="True",
                          pre="2 > 1",
                          post="4").def_var("a", "5").def_var("b", "6")

        evaluator = ConceptEvaluator()
        item = self.pretval(concept)
        result = evaluator.eval(context, item)

        assert result.who == evaluator.name
        assert result.status
        assert result.value.name == "foo"
        assert result.value.get_value(ConceptParts.WHERE) == True
        assert result.value.get_value(ConceptParts.PRE) == True
        assert result.value.get_value(ConceptParts.POST) == 4
        assert result.value.get_value("a") == 5
        assert result.value.get_value("b") == 6
        assert result.value.key == "foo"
        assert result.parents == [item]

    def test_body_is_returned_when_defined_and_requested(self):
        context = self.get_context()
        context.protected_hints.add(BuiltinConcepts.EVAL_BODY_REQUESTED)
        concept = Concept(name="foo",
                          body="'I have a value'",
                          where="True",
                          pre="2",
                          post="3").set_value("a", "4").set_value("b", "5")

        evaluator = ConceptEvaluator(return_body=True)
        item = self.pretval(concept)
        result = evaluator.eval(context, item)

        assert result.who == evaluator.name
        assert result.status
        assert result.value == "I have a value"
        assert result.parents == [item]

    def test_body_is_not_returned_if_not_requested(self):
        context = self.get_context()
        concept = Concept(name="foo",
                          body="'I have a value'",
                          where="True",
                          pre="2",
                          post="3").set_value("a", "4").set_value("b", "5")

        evaluator = ConceptEvaluator(return_body=False)  # which is the default behaviour
        item = self.pretval(concept)
        result = evaluator.eval(context, item)

        assert result.who == evaluator.name
        assert result.status
        assert result.value == concept
        assert result.parents == [item]

    def test_i_can_eval_if_with_the_same_name_is_defined_in_the_context(self):
        # If we evaluate Concept("foo", body="a").set_value("a", "'property_a'")
        # ConceptEvaluator will be called to resolve 'a' while we know that 'a' refers to the string 'property_a'

        context = self.get_context()
        context.obj = Concept("other").set_value("foo", "'some_other_value'")
        concept = Concept(name="foo")

        item = self.pretval(concept)
        result = ConceptEvaluator().eval(context, item)

        assert result.status
        assert result.value == "'some_other_value'"

    def test_i_cannot_recognize_a_concept_if_one_of_the_prop_is_unknown(self):
        context = self.get_context()
        context.protected_hints.add(BuiltinConcepts.EVAL_BODY_REQUESTED)
        context.sheerka.test_only_add_in_cache(Concept(name="one").init_key())
        concept_plus = context.sheerka.test_only_add_in_cache(Concept(name="a plus b")
                                                              .def_var("a", "one")
                                                              .def_var("b", "two").init_key())

        evaluator = ConceptEvaluator()
        item = self.pretval(concept_plus)
        result = evaluator.eval(context, item)

        assert not result.status
        assert context.sheerka.isinstance(result.value, BuiltinConcepts.CONCEPT_EVAL_ERROR)
        assert result.value.concept == concept_plus
        assert result.value.property_name == "b"
        assert context.sheerka.isinstance(result.value.error, BuiltinConcepts.ERROR)

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

        error_concept = context.sheerka.new(BuiltinConcepts.ERROR)
        item = self.pretval(error_concept)
        result = ConceptEvaluator().eval(context, item)

        assert not context.sheerka.is_success(error_concept)  # it's indeed an error
        assert result.status
        assert result.value == error_concept