import unittest
import warnings

from mongoengine import *
from mongoengine.tests import query_counter


class TestWarnings(unittest.TestCase):

    def setUp(self):
        conn = connect(db='mongoenginetest')
        self.warning_list = []
        self.showwarning_default = warnings.showwarning
        warnings.showwarning = self.append_to_warning_list

    def append_to_warning_list(self, message, category, *args):
        self.warning_list.append({"message": message,
                                  "category": category})

    def tearDown(self):
        # restore default handling of warnings
        warnings.showwarning = self.showwarning_default

    def test_allow_inheritance_future_warning(self):
        """Add FutureWarning for future allow_inhertiance default change.
        """

        class SimpleBase(Document):
            a = IntField()

        class InheritedClass(SimpleBase):
            b = IntField()

        InheritedClass()
        self.assertEqual(len(self.warning_list), 1)
        warning = self.warning_list[0]
        self.assertEqual(FutureWarning, warning["category"])
        self.assertTrue("InheritedClass" in str(warning["message"]))

    def test_dbref_reference_field_future_warning(self):

        class Person(Document):
            name = StringField()
            parent = ReferenceField('self')

        Person.drop_collection()

        p1 = Person()
        p1.parent = None
        p1.save()

        p2 = Person(name="Wilson Jr")
        p2.parent = p1
        p2.save(cascade=False)

        self.assertTrue(len(self.warning_list) > 0)
        warning = self.warning_list[0]
        self.assertEqual(FutureWarning, warning["category"])
        self.assertTrue("ReferenceFields will default to using ObjectId"
                        in str(warning["message"]))

    def test_document_save_cascade_future_warning(self):

        class Person(Document):
            name = StringField()
            parent = ReferenceField('self')

        Person.drop_collection()

        p1 = Person(name="Wilson Snr")
        p1.parent = None
        p1.save()

        p2 = Person(name="Wilson Jr")
        p2.parent = p1
        p2.parent.name = "Poppa Wilson"
        p2.save()

        self.assertTrue(len(self.warning_list) > 0)
        if len(self.warning_list) > 1:
            print self.warning_list
        warning = self.warning_list[0]
        self.assertEqual(FutureWarning, warning["category"])
        self.assertTrue("Cascading saves will default to off in 0.8"
                        in str(warning["message"]))

    def test_document_collection_syntax_warning(self):

        class NonAbstractBase(Document):
            pass

        class InheritedDocumentFailTest(NonAbstractBase):
            meta = {'collection': 'fail'}

        warning = self.warning_list[0]
        self.assertEqual(SyntaxWarning, warning["category"])
        self.assertEqual('non_abstract_base',
                         InheritedDocumentFailTest._get_collection_name())