# Copyright 2011 OpenStack Foundation.
# All Rights Reserved.
#
#    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.

import errno
import hashlib
import os
import shutil
import stat
import tempfile
import uuid

from oslotest import base as test_base
import six

from oslo_utils import fileutils


TEST_PERMISSIONS = stat.S_IRWXU


class EnsureTree(test_base.BaseTestCase):
    def test_ensure_tree(self):
        tmpdir = tempfile.mkdtemp()
        try:
            testdir = '%s/foo/bar/baz' % (tmpdir,)
            fileutils.ensure_tree(testdir, TEST_PERMISSIONS)
            self.assertTrue(os.path.isdir(testdir))
            self.assertEqual(os.stat(testdir).st_mode,
                             TEST_PERMISSIONS | stat.S_IFDIR)
        finally:
            if os.path.exists(tmpdir):
                shutil.rmtree(tmpdir)


class DeleteIfExists(test_base.BaseTestCase):
    def test_file_present(self):
        tmpfile = tempfile.mktemp()

        open(tmpfile, 'w')
        fileutils.delete_if_exists(tmpfile)
        self.assertFalse(os.path.exists(tmpfile))

    def test_file_absent(self):
        tmpfile = tempfile.mktemp()

        fileutils.delete_if_exists(tmpfile)
        self.assertFalse(os.path.exists(tmpfile))

    def test_dir_present(self):
        tmpdir = tempfile.mktemp()
        os.mkdir(tmpdir)

        fileutils.delete_if_exists(tmpdir, remove=os.rmdir)
        self.assertFalse(os.path.exists(tmpdir))

    def test_file_error(self):
        def errm(path):
            raise OSError(errno.EINVAL, '')

        tmpfile = tempfile.mktemp()

        open(tmpfile, 'w')
        self.assertRaises(OSError, fileutils.delete_if_exists, tmpfile, errm)
        os.unlink(tmpfile)


class RemovePathOnError(test_base.BaseTestCase):
    def test_error(self):
        tmpfile = tempfile.mktemp()
        open(tmpfile, 'w')

        try:
            with fileutils.remove_path_on_error(tmpfile):
                raise Exception
        except Exception:
            self.assertFalse(os.path.exists(tmpfile))

    def test_no_error(self):
        tmpfile = tempfile.mktemp()
        open(tmpfile, 'w')

        with fileutils.remove_path_on_error(tmpfile):
            pass
        self.assertTrue(os.path.exists(tmpfile))
        os.unlink(tmpfile)

    def test_remove(self):
        tmpfile = tempfile.mktemp()
        open(tmpfile, 'w')

        try:
            with fileutils.remove_path_on_error(tmpfile, remove=lambda x: x):
                raise Exception
        except Exception:
            self.assertTrue(os.path.exists(tmpfile))
        os.unlink(tmpfile)

    def test_remove_dir(self):
        tmpdir = tempfile.mktemp()
        os.mkdir(tmpdir)

        try:
            with fileutils.remove_path_on_error(
                    tmpdir,
                    lambda path: fileutils.delete_if_exists(path, os.rmdir)):
                raise Exception
        except Exception:
            self.assertFalse(os.path.exists(tmpdir))


class WriteToTempfileTestCase(test_base.BaseTestCase):
    def setUp(self):
        super(WriteToTempfileTestCase, self).setUp()
        self.content = 'testing123'.encode('ascii')

    def check_file_content(self, path):
        with open(path, 'r') as fd:
            ans = fd.read()
            self.assertEqual(self.content, six.b(ans))

    def test_file_without_path_and_suffix(self):
        res = fileutils.write_to_tempfile(self.content)
        self.assertTrue(os.path.exists(res))

        (basepath, tmpfile) = os.path.split(res)
        self.assertTrue(basepath.startswith(tempfile.gettempdir()))
        self.assertTrue(tmpfile.startswith('tmp'))

        self.check_file_content(res)

    def test_file_with_not_existing_path(self):
        random_dir = uuid.uuid4().hex
        path = '/tmp/%s/test1' % random_dir
        res = fileutils.write_to_tempfile(self.content, path=path)
        self.assertTrue(os.path.exists(res))
        (basepath, tmpfile) = os.path.split(res)
        self.assertEqual(basepath, path)
        self.assertTrue(tmpfile.startswith('tmp'))

        self.check_file_content(res)
        shutil.rmtree('/tmp/' + random_dir)

    def test_file_with_not_default_suffix(self):
        suffix = '.conf'
        res = fileutils.write_to_tempfile(self.content, suffix=suffix)
        self.assertTrue(os.path.exists(res))

        (basepath, tmpfile) = os.path.split(res)
        self.assertTrue(basepath.startswith(tempfile.gettempdir()))
        self.assertTrue(tmpfile.startswith('tmp'))
        self.assertTrue(tmpfile.endswith('.conf'))

        self.check_file_content(res)

    def test_file_with_not_existing_path_and_not_default_suffix(self):
        suffix = '.txt'
        random_dir = uuid.uuid4().hex
        path = '/tmp/%s/test2' % random_dir
        res = fileutils.write_to_tempfile(self.content,
                                          path=path,
                                          suffix=suffix)
        self.assertTrue(os.path.exists(res))
        (basepath, tmpfile) = os.path.split(res)
        self.assertTrue(tmpfile.startswith('tmp'))
        self.assertEqual(basepath, path)
        self.assertTrue(tmpfile.endswith(suffix))

        self.check_file_content(res)
        shutil.rmtree('/tmp/' + random_dir)

    def test_file_with_not_default_prefix(self):
        prefix = 'test'
        res = fileutils.write_to_tempfile(self.content, prefix=prefix)
        self.assertTrue(os.path.exists(res))

        (basepath, tmpfile) = os.path.split(res)
        self.assertTrue(tmpfile.startswith(prefix))
        self.assertTrue(basepath.startswith(tempfile.gettempdir()))

        self.check_file_content(res)


class TestComputeFileChecksum(test_base.BaseTestCase):

    def setUp(self):
        super(TestComputeFileChecksum, self).setUp()
        self.content = 'fake_content'.encode('ascii')

    def check_file_content(self, content, path):
        with open(path, 'r') as fd:
            ans = fd.read()
            self.assertEqual(content, six.b(ans))

    def test_compute_checksum_default_algorithm(self):
        path = fileutils.write_to_tempfile(self.content)
        self.assertTrue(os.path.exists(path))
        self.check_file_content(self.content, path)

        expected_checksum = hashlib.sha256()
        expected_checksum.update(self.content)

        actual_checksum = fileutils.compute_file_checksum(path)

        self.assertEqual(expected_checksum.hexdigest(), actual_checksum)

    def test_compute_checksum_named_algorithm(self):
        path = fileutils.write_to_tempfile(self.content)
        self.assertTrue(os.path.exists(path))
        self.check_file_content(self.content, path)

        expected_checksum = hashlib.sha512()
        expected_checksum.update(self.content)

        actual_checksum = fileutils.compute_file_checksum(path,
                                                          algorithm='sha512')

        self.assertEqual(expected_checksum.hexdigest(), actual_checksum)

    def test_compute_checksum_invalid_algorithm(self):
        path = fileutils.write_to_tempfile(self.content)
        self.assertTrue(os.path.exists(path))
        self.check_file_content(self.content, path)

        self.assertRaises(ValueError, fileutils.compute_file_checksum,
                          path, algorithm='foo')

    def test_file_does_not_exist(self):
        random_file_name = uuid.uuid4().hex
        path = os.path.join('/tmp', random_file_name)
        self.assertRaises(IOError, fileutils.compute_file_checksum, path)

    def test_generic_io_error(self):
        tempdir = tempfile.mkdtemp()
        self.assertRaises(IOError, fileutils.compute_file_checksum, tempdir)


class LastBytesTestCase(test_base.BaseTestCase):
    """Test the last_bytes() utility method."""

    def setUp(self):
        super(LastBytesTestCase, self).setUp()
        self.content = b'1234567890'

    def test_truncated(self):
        res = fileutils.write_to_tempfile(self.content)
        self.assertTrue(os.path.exists(res))
        out, unread_bytes = fileutils.last_bytes(res, 5)
        self.assertEqual(b'67890', out)
        self.assertGreater(unread_bytes, 0)

    def test_read_all(self):
        res = fileutils.write_to_tempfile(self.content)
        self.assertTrue(os.path.exists(res))
        out, unread_bytes = fileutils.last_bytes(res, 1000)
        self.assertEqual(b'1234567890', out)
        self.assertEqual(0, unread_bytes)

    def test_non_exist_file(self):
        self.assertRaises(IOError, fileutils.last_bytes,
                          'non_exist_file', 1000)