import logging

from django.template import Engine, Variable, VariableDoesNotExist

from django.test import SimpleTestCase

class VariableResolveLoggingTests(SimpleTestCase):

    loglevel = logging.DEBUG

    def test_log_on_variable_does_not_exist_silent(self):

        class TestObject:

            class SilentDoesNotExist(Exception):

                silent_variable_failure = True

            @property

            def template_name(self):

                return "template_name"

            @property

            def template(self):

                return Engine().from_string("")

            @property

            def article(self):

                raise TestObject.SilentDoesNotExist("Attribute does not exist.")

            def __iter__(self):

                return (attr for attr in dir(TestObject) if attr[:2] != "__")

            def __getitem__(self, item):

                return self.__dict__[item]

        with self.assertLogs("django.template", self.loglevel) as cm:

            Variable("article").resolve(TestObject())

        self.assertEqual(len(cm.records), 1)

        log_record = cm.records[0]

        self.assertEqual(

            log_record.getMessage(),

            "Exception while resolving variable 'article' in template 'template_name'.",

        )

        self.assertIsNotNone(log_record.exc_info)

        raised_exception = log_record.exc_info[1]

        self.assertEqual(str(raised_exception), "Attribute does not exist.")

    def test_log_on_variable_does_not_exist_not_silent(self):

        with self.assertLogs("django.template", self.loglevel) as cm:

            with self.assertRaises(VariableDoesNotExist):

                Variable("article.author").resolve({"article": {"section": "News"}})

        self.assertEqual(len(cm.records), 1)

        log_record = cm.records[0]

        self.assertEqual(

            log_record.getMessage(),

            "Exception while resolving variable 'author' in template 'unknown'.",

        )

        self.assertIsNotNone(log_record.exc_info)

        raised_exception = log_record.exc_info[1]

        self.assertEqual(

            str(raised_exception),

            "Failed lookup for key [author] in {'section': 'News'}",

        )

    def test_no_log_when_variable_exists(self):

        with self.assertNoLogs("django.template", self.loglevel):

            Variable("article.section").resolve({"article": {"section": "News"}})