from datetime import date, datetime, timedelta

from django.conf import settings
from django.contrib.auth.models import User
from django.contrib.auth.tokens import PasswordResetTokenGenerator
from django.test import TestCase
from django.test.utils import ignore_warnings
from django.utils.deprecation import RemovedInDjango40Warning

from .models import CustomEmailField


class MockedPasswordResetTokenGenerator(PasswordResetTokenGenerator):
    def __init__(self, now):
        self._now_val = now
        super().__init__()

    def _now(self):
        return self._now_val


class TokenGeneratorTest(TestCase):

    def test_make_token(self):
        user = User.objects.create_user('tokentestuser', 'test2@example.com', 'testpw')
        p0 = PasswordResetTokenGenerator()
        tk1 = p0.make_token(user)
        self.assertIs(p0.check_token(user, tk1), True)

    def test_10265(self):
        """
        The token generated for a user created in the same request
        will work correctly.
        """
        user = User.objects.create_user('comebackkid', 'test3@example.com', 'testpw')
        user_reload = User.objects.get(username='comebackkid')
        p0 = MockedPasswordResetTokenGenerator(datetime.now())
        tk1 = p0.make_token(user)
        tk2 = p0.make_token(user_reload)
        self.assertEqual(tk1, tk2)

    def test_token_with_different_email(self):
        """Updating the user email address invalidates the token."""
        tests = [
            (CustomEmailField, None),
            (CustomEmailField, 'test4@example.com'),
            (User, 'test4@example.com'),
        ]
        for model, email in tests:
            with self.subTest(model=model.__qualname__, email=email):
                user = model.objects.create_user(
                    'changeemailuser',
                    email=email,
                    password='testpw',
                )
                p0 = PasswordResetTokenGenerator()
                tk1 = p0.make_token(user)
                self.assertIs(p0.check_token(user, tk1), True)
                setattr(user, user.get_email_field_name(), 'test4new@example.com')
                user.save()
                self.assertIs(p0.check_token(user, tk1), False)

    def test_timeout(self):
        """The token is valid after n seconds, but no greater."""
        # Uses a mocked version of PasswordResetTokenGenerator so we can change
        # the value of 'now'.
        user = User.objects.create_user('tokentestuser', 'test2@example.com', 'testpw')
        now = datetime.now()
        p0 = MockedPasswordResetTokenGenerator(now)
        tk1 = p0.make_token(user)
        p1 = MockedPasswordResetTokenGenerator(
            now + timedelta(seconds=settings.PASSWORD_RESET_TIMEOUT)
        )
        self.assertIs(p1.check_token(user, tk1), True)
        p2 = MockedPasswordResetTokenGenerator(
            now + timedelta(seconds=(settings.PASSWORD_RESET_TIMEOUT + 1))
        )
        self.assertIs(p2.check_token(user, tk1), False)
        with self.settings(PASSWORD_RESET_TIMEOUT=60 * 60):
            p3 = MockedPasswordResetTokenGenerator(
                now + timedelta(seconds=settings.PASSWORD_RESET_TIMEOUT)
            )
            self.assertIs(p3.check_token(user, tk1), True)
            p4 = MockedPasswordResetTokenGenerator(
                now + timedelta(seconds=(settings.PASSWORD_RESET_TIMEOUT + 1))
            )
            self.assertIs(p4.check_token(user, tk1), False)

    def test_legacy_days_timeout(self):
        # RemovedInDjango40Warning: pre-Django 3.1 tokens will be invalid.
        class LegacyPasswordResetTokenGenerator(MockedPasswordResetTokenGenerator):
            """Pre-Django 3.1 tokens generator."""
            def _num_seconds(self, dt):
                # Pre-Django 3.1 tokens use days instead of seconds.
                return (dt.date() - date(2001, 1, 1)).days

        user = User.objects.create_user('tokentestuser', 'test2@example.com', 'testpw')
        now = datetime.now()
        p0 = LegacyPasswordResetTokenGenerator(now)
        tk1 = p0.make_token(user)
        p1 = MockedPasswordResetTokenGenerator(
            now + timedelta(seconds=settings.PASSWORD_RESET_TIMEOUT),
        )
        self.assertIs(p1.check_token(user, tk1), True)
        p2 = MockedPasswordResetTokenGenerator(
            now + timedelta(seconds=(settings.PASSWORD_RESET_TIMEOUT + 24 * 60 * 60)),
        )
        self.assertIs(p2.check_token(user, tk1), False)

    def test_check_token_with_nonexistent_token_and_user(self):
        user = User.objects.create_user('tokentestuser', 'test2@example.com', 'testpw')
        p0 = PasswordResetTokenGenerator()
        tk1 = p0.make_token(user)
        self.assertIs(p0.check_token(None, tk1), False)
        self.assertIs(p0.check_token(user, None), False)

    def test_token_with_different_secret(self):
        """
        A valid token can be created with a secret other than SECRET_KEY by
        using the PasswordResetTokenGenerator.secret attribute.
        """
        user = User.objects.create_user('tokentestuser', 'test2@example.com', 'testpw')
        new_secret = 'abcdefghijkl'
        # Create and check a token with a different secret.
        p0 = PasswordResetTokenGenerator()
        p0.secret = new_secret
        tk0 = p0.make_token(user)
        self.assertIs(p0.check_token(user, tk0), True)
        # Create and check a token with the default secret.
        p1 = PasswordResetTokenGenerator()
        self.assertEqual(p1.secret, settings.SECRET_KEY)
        self.assertNotEqual(p1.secret, new_secret)
        tk1 = p1.make_token(user)
        # Tokens created with a different secret don't validate.
        self.assertIs(p0.check_token(user, tk1), False)
        self.assertIs(p1.check_token(user, tk0), False)

    @ignore_warnings(category=RemovedInDjango40Warning)
    def test_token_default_hashing_algorithm(self):
        user = User.objects.create_user('tokentestuser', 'test2@example.com', 'testpw')
        with self.settings(DEFAULT_HASHING_ALGORITHM='sha1'):
            generator = PasswordResetTokenGenerator()
            self.assertEqual(generator.algorithm, 'sha1')
            token = generator.make_token(user)
            self.assertIs(generator.check_token(user, token), True)

    def test_legacy_token_validation(self):
        # RemovedInDjango40Warning: pre-Django 3.1 tokens will be invalid.
        user = User.objects.create_user('tokentestuser', 'test2@example.com', 'testpw')
        p_old_generator = PasswordResetTokenGenerator()
        p_old_generator.algorithm = 'sha1'
        p_new_generator = PasswordResetTokenGenerator()

        legacy_token = p_old_generator.make_token(user)
        self.assertIs(p_old_generator.check_token(user, legacy_token), True)
        self.assertIs(p_new_generator.check_token(user, legacy_token), True)
