#!/usr/bin/env python3
#
# Copyright (c) 2016-present, Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree. An additional grant
# of patent rights can be found in the PATENTS file in the same directory.

from .lib import testcase
import errno
import os
import stat
import subprocess
import time
import unittest

@testcase.eden_repo_test
class SetAttrTest:
    def populate_repo(self):
        self.repo.write_file('hello', 'hola\n')
        self.repo.commit('Initial commit.')

    # mtime should not get changed on permission changes
    # to the file but currently its changing in Edenfs
    @unittest.expectedFailure
    def test_chmod(self):
        filename = os.path.join(self.mount, 'hello')

        st = os.lstat(filename)
        os.chmod(filename, st.st_mode | stat.S_IROTH)
        new_st = os.lstat(filename)
        self.assertGreaterEqual(new_st.st_atime, st.st_atime)

        self.assertEqual(new_st.st_mtime, st.st_mtime)
        self.assertEqual(new_st.st_atime, st.st_atime)
        self.assertGreaterEqual(new_st.st_ctime, st.st_ctime)
        self.assertEqual(new_st.st_mode, st.st_mode | stat.S_IROTH)

    def test_chown(self):
        filename = os.path.join(self.mount, 'hello')

        # Chown should fail with EPERM unless we are setting it
        # to the same current ownership
        st = os.lstat(filename)
        os.chown(filename, st.st_uid, st.st_gid)

        with self.assertRaises(OSError) as context:
            os.chown(filename, st.st_uid + 1, st.st_gid)
        self.assertEqual(errno.EPERM, context.exception.errno,
                         msg="changing uid of a file should raise EPERM")

        with self.assertRaises(OSError) as context:
            os.chown(filename, st.st_uid, st.st_gid + 1)
        self.assertEqual(errno.EPERM, context.exception.errno,
                         msg="changing gid of a file should raise EPERM")

    def test_truncate(self):
        filename = os.path.join(self.mount, 'hello')
        st = os.lstat(filename)

        with open(filename, 'r+') as f:
            f.truncate(0)
            self.assertEqual('', f.read())

        new_st = os.lstat(filename)
        self.assertEqual(new_st.st_size, 0)
        self.assertGreaterEqual(new_st.st_atime, st.st_atime)
        self.assertGreaterEqual(new_st.st_ctime, st.st_ctime)
        self.assertGreaterEqual(new_st.st_mtime, st.st_mtime)

    def test_utime(self):
        filename = os.path.join(self.mount, 'hello')

        # Update the atime and mtime to a time 5 seconds in the past.
        #
        # We round to the nearest second to avoid timestamp granularity issues.
        # (Eden currently uses the underlying overlay filesystem to store the
        # timestamps, and it might not necessarily support high resolution
        # timestamps.)
        timestamp = int(time.time() - 5)
        os.utime(filename, (timestamp, timestamp))
        st = os.lstat(filename)

        self.assertEqual(st.st_atime, timestamp)
        self.assertEqual(st.st_mtime, timestamp)

    def test_touch(self):
        filename = os.path.join(self.mount, 'hello')

        now = time.time()
        subprocess.check_call(['touch', filename])
        st = os.lstat(filename)

        self.assertGreaterEqual(st.st_atime, now)
        self.assertGreaterEqual(st.st_mtime, now)

        newfile = os.path.join(self.mount, 'touched-new-file')
        now = time.time()
        subprocess.check_call(['touch', newfile])
        st = os.lstat(newfile)

        self.assertGreaterEqual(st.st_atime, now)
        self.assertGreaterEqual(st.st_mtime, now)

    def test_dir_addfile(self):
        dirname = os.path.join(self.mount, 'test_dir')
        self.mkdir('test_dir')

        st = os.lstat(dirname)
        self.write_file('test_file', 'test string')
        new_st = os.lstat(dirname)

        self.assertEqual(new_st.st_atime, st.st_atime)
        self.assertGreaterEqual(new_st.st_ctime, st.st_ctime)
        self.assertGreaterEqual(new_st.st_mtime, st.st_mtime)

    def test_dir_delfile(self):
        dirname = os.path.join(self.mount, 'test_dir')
        self.mkdir('test_dir')
        self.write_file('test_file', 'test string')
        st = os.lstat(dirname)

        self.rm('test_file')
        new_st = os.lstat(dirname)

        self.assertEqual(new_st.st_atime, st.st_atime)
        self.assertGreaterEqual(new_st.st_ctime, st.st_ctime)
        self.assertGreaterEqual(new_st.st_mtime, st.st_mtime)

    def test_dir_change_filecontents(self):
        dirname = os.path.join(self.mount, 'test_dir')
        self.mkdir('test_dir')

        self.write_file('test_file', 'test string')
        st = os.lstat(dirname)
        self.write_file('test_file', 'test string 1')
        new_st = os.lstat(dirname)

        self.assertEqual(new_st.st_mtime, st.st_mtime)
        self.assertEqual(new_st.st_ctime, st.st_ctime)
        self.assertEqual(new_st.st_mtime, st.st_mtime)

    # Changing permisssions of directory should change
    # only ctime of the directory, but currently chmod
    # is not implemented for directories in edenfs
    @unittest.expectedFailure
    def test_dir_change_perm(self):
        dirname = os.path.join(self.mount, 'test_dir')
        self.mkdir('test_dir')

        st = os.lstat(dirname)
        os.chmod(dirname, st.st_mode | stat.S_IROTH)
        new_st = os.lstat(dirname)

        self.assertEqual(new_st.st_mtime, st.st_mtime)
        self.assertEqual(new_st.st_atime, st.st_atime)
        self.assertGreaterEqual(new_st.st_ctime, st.st_ctime)

    # Opening the file in read mode should update the atime
    # But it is not being updated in Edenfs
    @unittest.expectedFailure
    def test_timestamp_openfiles(self):
        filename = os.path.join(self.mount, 'hello')
        st = os.lstat(filename)
        with open(filename, 'r') as f:
            f.read()
            new_st = os.lstat(filename)
            self.assertEqual(new_st.st_mtime, st.st_mtime)
            self.assertEqual(new_st.st_atime, st.st_atime)
            self.assertEqual(new_st.st_ctime, st.st_ctime)
            f.close()

        new_st = os.lstat(filename)
        self.assertEqual(new_st.st_mtime, st.st_mtime)
        self.assertGreater(new_st.st_atime, st.st_atime)
        self.assertEqual(new_st.st_ctime, st.st_ctime)