import pathlib
import tempfile
import unittest
import unittest.mock

import modulus.filesystem

class PublicationTests(unittest.TestCase):
  def setUp(self):
    self.temporary = tempfile.TemporaryDirectory()
    self.addCleanup(self.temporary.cleanup)
    self.root = pathlib.Path(self.temporary.name)
    self.source, self.target = self.root / 'new', self.root / 'installed'
    for path, text in ((self.source, 'new'), (self.target, 'old')):
      path.mkdir()
      (path / 'content').write_text(text)
  def test_publish_replaces_complete_directory(self):
    with modulus.filesystem.publish_directories([(self.source, self.target)]):
      self.assertEqual((self.target / 'content').read_text(), 'new')
    self.assertFalse(self.source.exists())
    self.assertEqual(list(self.root.iterdir()), [self.target])
  def test_failure_restores_previous_directory(self):
    with self.assertRaisesRegex(RuntimeError, 'failed'):
      with modulus.filesystem.publish_directories([(self.source, self.target)]):
        raise RuntimeError('failed')
    self.assertEqual((self.target / 'content').read_text(), 'old')
    self.assertFalse(list(self.root.glob('.publish_*')))
  def test_failed_second_replacement_rolls_back_first(self):
    second = self.root / 'second'
    second.mkdir()
    rename = pathlib.Path.rename
    def fail(path, destination):
      if path == second:
        raise OSError('failed')
      return rename(path, destination)
    with unittest.mock.patch.object(pathlib.Path, 'rename', fail), self.assertRaises(OSError):
      with modulus.filesystem.publish_directories([(self.source, self.target), (second, self.root / 'last')]):
        pass
    self.assertEqual((self.target / 'content').read_text(), 'old')
  def test_overlaps_and_symlinks_rejected_before_replacement(self):
    link = self.root / 'link'
    link.symlink_to(self.target, target_is_directory=True)
    for target in (self.source, self.source / 'child', self.source / '..' / 'new', self.root, link, link / 'child'):
      with self.subTest(target=target), self.assertRaises(ValueError):
        with modulus.filesystem.publish_directories([(self.source, target)]):
          pass
    self.assertEqual((self.target / 'content').read_text(), 'old')
  def test_failed_rollback_retains_the_previous_directory_for_recovery(self):
    rename = pathlib.Path.rename
    def fail(path, destination):
      if path.name == 'previous':
        raise OSError('restore failed')
      return rename(path, destination)
    with unittest.mock.patch.object(pathlib.Path, 'rename', fail), self.assertRaisesRegex(RuntimeError, 'recovery directories retained'):
      with modulus.filesystem.publish_directories([(self.source, self.target)]):
        raise RuntimeError('publication failed')
    backup = next(self.root.glob('.publish_*/previous/content'))
    self.assertEqual(backup.read_text(), 'old')