import datetime
import unittest
from freezegun import freeze_time
from unittest.mock import patch, MagicMock
from zoho_auth import ZohoToken

class TestZohoToken(unittest.TestCase):
    """Test the ZohoToken class"""

    @patch('zoho_auth.request')
    def test_fetches_token(self, mock_request):
        """Test that the ZohoAuth class fetches a token from the web service"""
        mock_response = MagicMock()
        mock_response.read.return_value.decode.return_value = '{"access_token": "mock_access_token", "expires_in": 3600}'
        mock_request.urlopen.return_value.__enter__.return_value = mock_response

        auth = ZohoToken('mock_client_id', 'mock_client_secret', 'mock_refresh_token')

        # Assert that the token was fetched
        self.assertEqual(auth.get_token(), 'mock_access_token')
        mock_request.Request.assert_called_with('https://accounts.zoho.com/oauth/v2/token?refresh_token=mock_refresh_token&client_id=mock_client_id&client_secret=mock_client_secret&grant_type=refresh_token', method='POST')

    @patch('zoho_auth.request')
    @freeze_time('2009-06-15 09:00:00', as_kwarg='frozen_time')
    def test_updates_token_after_expiration(self, mock_request, frozen_time):
        """Test that ZohoAuth fetches a new token after the previous one expires"""
        mock_response = MagicMock()
        mock_response.read.return_value.decode.return_value = '{"access_token": "mock_access_token", "expires_in": 3600}'
        mock_request.urlopen.return_value.__enter__.return_value = mock_response

        auth = ZohoToken('mock_client_id', 'mock_client_secret', 'mock_refresh_token')
        self.assertEqual(auth.expires_at, datetime.datetime(2009, 6, 15, 10, 0, 0))

        mock_response.read.return_value.decode.return_value = '{"access_token": "updated_mock_access_token", "expires_in": 3600}'
        frozen_time.tick(datetime.timedelta(seconds=3599))
        token = auth.get_token()
        self.assertEqual(token, 'mock_access_token')
        frozen_time.tick(datetime.timedelta(seconds=1))
        token = auth.get_token()
        self.assertEqual(token, 'updated_mock_access_token')

if __name__ == '__main__':
    unittest.main()