#!/usr/bin/env python3
#
# Copyright 2018, The Android Open Source Project
#
# 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.

"""ATest Integration Test Class.

The purpose is to prevent potential side-effects from breaking ATest at the
early stage while landing CLs with potential side-effects.

It forks a subprocess with ATest commands to validate if it can pass all the
finding, running logic of the python code, and waiting for TF to exit properly.
    - When running with ROBOLECTRIC tests, it runs without TF, and will exit
    the subprocess with the message "All tests passed"
    - If FAIL, it means something breaks ATest unexpectedly!
"""

from __future__ import print_function

import os
import subprocess
import sys
import tempfile
import time
import unittest


_TEST_RUN_DIR_PREFIX = 'atest_integration_tests_%s_'
_LOG_FILE = 'integration_tests.log'
_FAILED_LINE_LIMIT = 50
_EXIT_TEST_FAILED = 1
_ALTERNATIVES = {'-dev'}
_INTEGRATION_TESTS = [
    os.path.join(
        os.environ.get('ANDROID_BUILD_TOP', os.getcwd()),
        'tools/asuite/atest/test_plans/INTEGRATION_TESTS',
    )
]


class ATestIntegrationTest(unittest.TestCase):
  """ATest Integration Test Class."""

  NAME = 'ATestIntegrationTest'
  EXECUTABLE = 'atest'
  OPTIONS = ''
  _RUN_CMD = '{exe} {options} {test}'
  _PASSED_CRITERIA = ['will be rescheduled', 'All tests passed']

  def setUp(self):
    """Set up stuff for testing."""
    self.full_env_vars = os.environ.copy()
    self.test_passed = False
    self.log = []

  def run_test(self, testcase):
    """Create a subprocess to execute the test command.

    Strategy:
        Fork a subprocess to wait for TF exit properly, and log the error
        if the exit code isn't 0.

    Args:
        testcase: A string of testcase name.
    """
    run_cmd_dict = {
        'exe': self.EXECUTABLE,
        'options': self.OPTIONS,
        'test': testcase,
    }
    run_command = self._RUN_CMD.format(**run_cmd_dict)
    try:
      subprocess.check_output(
          run_command,
          stderr=subprocess.PIPE,
          env=self.full_env_vars,
          shell=True,
      )
    except subprocess.CalledProcessError as e:
      self.log.append(e.output.decode())
      return False
    return True

  def get_failed_log(self):
    """Get a trimmed failed log.

    Strategy:
        In order not to show the unnecessary log such as build log,
        it's better to get a trimmed failed log that contains the
        most important information.

    Returns:
        A trimmed failed log.
    """
    failed_log = '\n'.join(filter(None, self.log[-_FAILED_LINE_LIMIT:]))
    return failed_log


def create_test_method(testcase, log_path):
  """Create a test method according to the testcase.

  Args:
      testcase: A testcase name.
      log_path: A file path for storing the test result.

  Returns:
      A created test method, and a test function name.
  """
  test_function_name = 'test_%s' % testcase.replace(' ', '_')

  # pylint: disable=missing-docstring
  def template_test_method(self):
    self.test_passed = self.run_test(testcase)
    open(log_path, 'a').write('\n'.join(self.log))
    failed_message = 'Running command: %s failed.\n' % testcase
    failed_message += '' if self.test_passed else self.get_failed_log()
    self.assertTrue(self.test_passed, failed_message)

  return test_function_name, template_test_method


def create_test_run_dir():
  """Create the test run directory in tmp.

  Returns:
      A string of the directory path.
  """
  utc_epoch_time = int(time.time())
  prefix = _TEST_RUN_DIR_PREFIX % utc_epoch_time
  return tempfile.mkdtemp(prefix=prefix)


if __name__ == '__main__':
  # TODO(b/129029189) Implement detail comparison check for dry-run mode.
  ARGS = sys.argv[1:]
  if ARGS:
    for exe in _ALTERNATIVES:
      if exe in ARGS:
        ARGS.remove(exe)
        ATestIntegrationTest.EXECUTABLE += exe
    ATestIntegrationTest.OPTIONS = ' '.join(ARGS)
  print('Running tests with {}\n'.format(ATestIntegrationTest.EXECUTABLE))
  try:
    LOG_PATH = os.path.join(create_test_run_dir(), _LOG_FILE)
    for TEST_PLANS in _INTEGRATION_TESTS:
      with open(TEST_PLANS) as test_plans:
        for test in test_plans:
          # Skip test when the line startswith #.
          if not test.strip() or test.strip().startswith('#'):
            continue
          test_func_name, test_func = create_test_method(test.strip(), LOG_PATH)
          setattr(ATestIntegrationTest, test_func_name, test_func)
    SUITE = unittest.TestLoader().loadTestsFromTestCase(ATestIntegrationTest)
    RESULTS = unittest.TextTestRunner(verbosity=2).run(SUITE)
  finally:
    if RESULTS.failures:
      print('Full test log is saved to %s' % LOG_PATH)
      sys.exit(_EXIT_TEST_FAILED)
    else:
      os.remove(LOG_PATH)