#!/usr/bin/python

"""
Copyright 2013 Google Inc.

Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.

Test results.py

TODO(epoger): Create a command to update the expected results (in
OUTPUT_DIR_EXPECTED) when appropriate.  For now, you should:
1. examine the results in OUTPUT_DIR_ACTUAL and make sure they are ok
2. rm -rf OUTPUT_DIR_EXPECTED
3. mv OUTPUT_DIR_ACTUAL OUTPUT_DIR_EXPECTED
Although, if you're using an SVN checkout, this will blow away .svn directories
within OUTPUT_DIR_EXPECTED, which wouldn't be good...

"""

import filecmp
import os
import shutil
import sys
import tempfile
import unittest

# Imports from within Skia
import results
import gm_json  # must import results first, so that gm_json will be in sys.path

PARENT_DIR = os.path.dirname(os.path.realpath(__file__))
INPUT_DIR = os.path.join(PARENT_DIR, 'tests', 'inputs')
OUTPUT_DIR_ACTUAL   = os.path.join(PARENT_DIR, 'tests', 'outputs', 'actual')
OUTPUT_DIR_EXPECTED = os.path.join(PARENT_DIR, 'tests', 'outputs', 'expected')


class ResultsTest(unittest.TestCase):

  def setUp(self):
    self._temp_dir = tempfile.mkdtemp()
    self._output_dir_actual   = os.path.join(OUTPUT_DIR_ACTUAL, self.id())
    self._output_dir_expected = os.path.join(OUTPUT_DIR_EXPECTED, self.id())
    create_empty_dir(self._output_dir_actual)

  def tearDown(self):
    shutil.rmtree(self._temp_dir)
    different_files = find_different_files(self._output_dir_actual,
                                           self._output_dir_expected)
    # Maybe we should move this assert elsewhere?  It's unusual to see an
    # assert within tearDown(), but my thinking was:
    # 1. Every test case will have some collection of output files that need to
    #    be validated.
    # 2. So put that validation within tearDown(), which will be called after
    #    every test case!
    #
    # I have confirmed that the test really does fail if this assert is
    # triggered.
    #
    # Ravi notes: if somebody later comes along and adds cleanup code below the
    # assert, then if tests fail, the artifacts will not be cleaned up.
    assert (not different_files), \
      ('found differing files between actual dir %s and expected dir %s: %s' %
       (self._output_dir_actual, self._output_dir_expected, different_files))

  def shortDescription(self):
    """Tell unittest framework to not print docstrings for test cases."""
    return None

  def test_gm(self):
    """Process results of a GM run with the Results object."""
    results_obj = results.Results(
        actuals_root=os.path.join(INPUT_DIR, 'gm-actuals'),
        expected_root=os.path.join(INPUT_DIR, 'gm-expectations'),
        generated_images_root=self._temp_dir)
    gm_json.WriteToFile(results_obj.get_results_of_type(results.RESULTS_ALL),
                        os.path.join(self._output_dir_actual, 'gm.json'))


# TODO(epoger): create_empty_dir(), find_different_files(), etc. should be
# extracted from this file to some common location, where they can be shared
# with download_test.py and other users.

def create_empty_dir(path):
  """Create an empty directory at the given path."""
  if os.path.isdir(path):
    shutil.rmtree(path)
  elif os.path.lexists(path):
    os.remove(path)
  os.makedirs(path)


def find_different_files(dir1, dir2, ignore_subtree_names=None):
  """Returns a list of any files that differ between the directory trees rooted
  at dir1 and dir2.

  Args:
    dir1: root of a directory tree; if nonexistent, will raise OSError
    dir2: root of another directory tree; if nonexistent, will raise OSError
    ignore_subtree_names: list of subtree directory names to ignore;
          defaults to ['.svn'], so all SVN files are ignores

  TODO(epoger): include the dirname within each filename (not just the
  basename), to make it easier to locate any differences
  """
  differing_files = []
  if ignore_subtree_names is None:
    ignore_subtree_names = ['.svn']
  dircmp = filecmp.dircmp(dir1, dir2, ignore=ignore_subtree_names)
  differing_files.extend(dircmp.left_only)
  differing_files.extend(dircmp.right_only)
  differing_files.extend(dircmp.common_funny)
  differing_files.extend(dircmp.diff_files)
  differing_files.extend(dircmp.funny_files)
  for common_dir in dircmp.common_dirs:
    differing_files.extend(find_different_files(
        os.path.join(dir1, common_dir), os.path.join(dir2, common_dir)))
  return differing_files


def main():
  suite = unittest.TestLoader().loadTestsFromTestCase(ResultsTest)
  unittest.TextTestRunner(verbosity=2).run(suite)


if __name__ == '__main__':
  main()