# Copyright 2021 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Tests for clusterfuzz_deployment.py"""

import os
import tempfile
import unittest
from unittest import mock
import urllib.error

from pyfakefs import fake_filesystem_unittest

import clusterfuzz_deployment
import config_utils

# NOTE: This integration test relies on
# https://github.com/google/oss-fuzz/tree/master/projects/example project.
EXAMPLE_PROJECT = 'example'

# An example fuzzer that triggers an error.
EXAMPLE_FUZZER = 'example_crash_fuzzer'


def _create_config(**kwargs):
  """Creates a config object and then sets every attribute that is a key in
  |kwargs| to the corresponding value. Asserts that each key in |kwargs| is an
  attribute of Config."""
  defaults = {'is_github': True, 'project_name': EXAMPLE_PROJECT}
  for default_key, default_value in defaults.items():
    if default_key not in kwargs:
      kwargs[default_key] = default_value

  with mock.patch('os.path.basename', return_value=None), mock.patch(
      'config_utils.get_project_src_path',
      return_value=None), mock.patch('config_utils._is_dry_run',
                                     return_value=True):
    config = config_utils.RunFuzzersConfig()

  for key, value in kwargs.items():
    assert hasattr(config, key), 'Config doesn\'t have attribute: ' + key
    setattr(config, key, value)
  return config


def _create_deployment(**kwargs):
  config = _create_config(**kwargs)
  return clusterfuzz_deployment.get_clusterfuzz_deployment(config)


class OSSFuzzTest(unittest.TestCase):
  """Tests OSSFuzz."""

  def test_download_corpus(self):
    """Tests that we can download a corpus for a valid project."""
    deployment = _create_deployment()
    with tempfile.TemporaryDirectory() as tmp_dir:
      with mock.patch('clusterfuzz_deployment.download_and_unpack_zip',
                      return_value=False) as mocked_download_and_unpack_zip:
        deployment.download_corpus(EXAMPLE_FUZZER, tmp_dir)
        (url, out_dir), _ = mocked_download_and_unpack_zip.call_args
        self.assertEqual(
            url, 'https://storage.googleapis.com/example-backup.'
            'clusterfuzz-external.appspot.com/corpus/libFuzzer/'
            'example_crash_fuzzer/public.zip')
        self.assertEqual(out_dir,
                         os.path.join(tmp_dir, 'cifuzz-corpus', EXAMPLE_FUZZER))

  def test_download_fail(self):
    """Tests that when downloading fails, None is returned."""
    deployment = _create_deployment()
    with tempfile.TemporaryDirectory() as tmp_dir:
      with mock.patch('clusterfuzz_deployment.download_and_unpack_zip',
                      return_value=False):
        corpus_path = deployment.download_corpus(EXAMPLE_FUZZER, tmp_dir)
        self.assertIsNone(corpus_path)

  def test_download_latest_build(self):
    """Tests that the build directory is downloaded once and no more."""
    deployment = _create_deployment()
    with tempfile.TemporaryDirectory() as tmp_dir:
      latest_name = deployment.get_latest_build_name()
      with mock.patch('clusterfuzz_deployment.OSSFuzz.get_latest_build_name',
                      return_value=latest_name):
        latest_build_path = deployment.download_latest_build(tmp_dir)
        self.assertNotEqual(len(os.listdir(latest_build_path)), 0)

  def test_get_latest_build_name(self):
    """Tests that the latest build name can be retrieved from GCS."""
    deployment = _create_deployment()
    latest_build_name = deployment.get_latest_build_name()
    self.assertTrue(latest_build_name.endswith('.zip'))
    self.assertTrue('address' in latest_build_name)


class DownloadUrlTest(unittest.TestCase):
  """Tests that download_url works."""
  URL = 'example.com/file'
  FILE_PATH = '/tmp/file'

  @mock.patch('time.sleep')
  @mock.patch('urllib.request.urlretrieve', return_value=True)
  def test_download_url_no_error(self, mocked_urlretrieve, _):
    """Tests that download_url works when there is no error."""
    self.assertTrue(
        clusterfuzz_deployment.download_url(self.URL, self.FILE_PATH))
    self.assertEqual(1, mocked_urlretrieve.call_count)

  @mock.patch('time.sleep')
  @mock.patch('logging.error')
  @mock.patch('urllib.request.urlretrieve',
              side_effect=urllib.error.HTTPError(None, None, None, None, None))
  def test_download_url_http_error(self, mocked_urlretrieve, mocked_error, _):
    """Tests that download_url doesn't retry when there is an HTTP error."""
    self.assertFalse(
        clusterfuzz_deployment.download_url(self.URL, self.FILE_PATH))
    mocked_error.assert_called_with('Unable to download from: %s.', self.URL)
    self.assertEqual(1, mocked_urlretrieve.call_count)

  @mock.patch('time.sleep')
  @mock.patch('logging.error')
  @mock.patch('urllib.request.urlretrieve', side_effect=ConnectionResetError)
  def test_download_url_connection_error(self, mocked_urlretrieve, mocked_error,
                                         mocked_sleep):
    """Tests that download_url doesn't retry when there is an HTTP error."""
    self.assertFalse(
        clusterfuzz_deployment.download_url(self.URL, self.FILE_PATH))
    self.assertEqual(3, mocked_urlretrieve.call_count)
    self.assertEqual(3, mocked_sleep.call_count)
    mocked_error.assert_called_with('Failed to download %s, %d times.',
                                    self.URL, 3)


class DownloadAndUnpackZipTest(fake_filesystem_unittest.TestCase):
  """Tests download_and_unpack_zip."""

  def setUp(self):
    self.setUpPyfakefs()

  def test_bad_zip_download(self):
    """Tests download_and_unpack_zip returns none when a bad zip is passed."""
    with open('/url_tmp.zip', 'w') as file_handle:
      file_handle.write('Test file.')
    with mock.patch('urllib.request.urlretrieve', return_value=True):
      self.assertFalse(
          clusterfuzz_deployment.download_and_unpack_zip(
              '/not/a/real/url', '/extract-directory'))


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