#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""POSIX specific tests."""

import datetime
import errno
import os
import subprocess
import sys
import time

import psutil
from psutil import BSD
from psutil import LINUX
from psutil import OSX
from psutil import POSIX
from psutil import SUNOS
from psutil._compat import callable
from psutil._compat import PY3
from psutil.tests import get_kernel_version
from psutil.tests import get_test_subprocess
from psutil.tests import mock
from psutil.tests import PYTHON
from psutil.tests import reap_children
from psutil.tests import retry_before_failing
from psutil.tests import run_test_module_by_name
from psutil.tests import sh
from psutil.tests import skip_on_access_denied
from psutil.tests import TRAVIS
from psutil.tests import unittest
from psutil.tests import wait_for_pid


def ps(cmd):
    """Expects a ps command with a -o argument and parse the result
    returning only the value of interest.
    """
    if not LINUX:
        cmd = cmd.replace(" --no-headers ", " ")
    if SUNOS:
        cmd = cmd.replace("-o command", "-o comm")
        cmd = cmd.replace("-o start", "-o stime")
    p = subprocess.Popen(cmd, shell=1, stdout=subprocess.PIPE)
    output = p.communicate()[0].strip()
    if PY3:
        output = str(output, sys.stdout.encoding)
    if not LINUX:
        output = output.split('\n')[1].strip()
    try:
        return int(output)
    except ValueError:
        return output


@unittest.skipUnless(POSIX, "not a POSIX system")
class TestProcess(unittest.TestCase):
    """Compare psutil results against 'ps' command line utility (mainly)."""

    @classmethod
    def setUpClass(cls):
        cls.pid = get_test_subprocess([PYTHON, "-E", "-O"],
                                      stdin=subprocess.PIPE).pid
        wait_for_pid(cls.pid)

    @classmethod
    def tearDownClass(cls):
        reap_children()

    # for ps -o arguments see: http://unixhelp.ed.ac.uk/CGI/man-cgi?ps

    def test_ppid(self):
        ppid_ps = ps("ps --no-headers -o ppid -p %s" % self.pid)
        ppid_psutil = psutil.Process(self.pid).ppid()
        self.assertEqual(ppid_ps, ppid_psutil)

    def test_uid(self):
        uid_ps = ps("ps --no-headers -o uid -p %s" % self.pid)
        uid_psutil = psutil.Process(self.pid).uids().real
        self.assertEqual(uid_ps, uid_psutil)

    def test_gid(self):
        gid_ps = ps("ps --no-headers -o rgid -p %s" % self.pid)
        gid_psutil = psutil.Process(self.pid).gids().real
        self.assertEqual(gid_ps, gid_psutil)

    def test_username(self):
        username_ps = ps("ps --no-headers -o user -p %s" % self.pid)
        username_psutil = psutil.Process(self.pid).username()
        self.assertEqual(username_ps, username_psutil)

    @skip_on_access_denied()
    @retry_before_failing()
    def test_rss_memory(self):
        # give python interpreter some time to properly initialize
        # so that the results are the same
        time.sleep(0.1)
        rss_ps = ps("ps --no-headers -o rss -p %s" % self.pid)
        rss_psutil = psutil.Process(self.pid).memory_info()[0] / 1024
        self.assertEqual(rss_ps, rss_psutil)

    @skip_on_access_denied()
    @retry_before_failing()
    def test_vsz_memory(self):
        # give python interpreter some time to properly initialize
        # so that the results are the same
        time.sleep(0.1)
        vsz_ps = ps("ps --no-headers -o vsz -p %s" % self.pid)
        vsz_psutil = psutil.Process(self.pid).memory_info()[1] / 1024
        self.assertEqual(vsz_ps, vsz_psutil)

    def test_name(self):
        # use command + arg since "comm" keyword not supported on all platforms
        name_ps = ps("ps --no-headers -o command -p %s" % (
            self.pid)).split(' ')[0]
        # remove path if there is any, from the command
        name_ps = os.path.basename(name_ps).lower()
        name_psutil = psutil.Process(self.pid).name().lower()
        self.assertEqual(name_ps, name_psutil)

    @unittest.skipIf(OSX or BSD,
                     'ps -o start not available')
    def test_create_time(self):
        time_ps = ps("ps --no-headers -o start -p %s" % self.pid).split(' ')[0]
        time_psutil = psutil.Process(self.pid).create_time()
        time_psutil_tstamp = datetime.datetime.fromtimestamp(
            time_psutil).strftime("%H:%M:%S")
        # sometimes ps shows the time rounded up instead of down, so we check
        # for both possible values
        round_time_psutil = round(time_psutil)
        round_time_psutil_tstamp = datetime.datetime.fromtimestamp(
            round_time_psutil).strftime("%H:%M:%S")
        self.assertIn(time_ps, [time_psutil_tstamp, round_time_psutil_tstamp])

    def test_exe(self):
        ps_pathname = ps("ps --no-headers -o command -p %s" %
                         self.pid).split(' ')[0]
        psutil_pathname = psutil.Process(self.pid).exe()
        try:
            self.assertEqual(ps_pathname, psutil_pathname)
        except AssertionError:
            # certain platforms such as BSD are more accurate returning:
            # "/usr/local/bin/python2.7"
            # ...instead of:
            # "/usr/local/bin/python"
            # We do not want to consider this difference in accuracy
            # an error.
            adjusted_ps_pathname = ps_pathname[:len(ps_pathname)]
            self.assertEqual(ps_pathname, adjusted_ps_pathname)

    def test_cmdline(self):
        ps_cmdline = ps("ps --no-headers -o command -p %s" % self.pid)
        psutil_cmdline = " ".join(psutil.Process(self.pid).cmdline())
        if SUNOS:
            # ps on Solaris only shows the first part of the cmdline
            psutil_cmdline = psutil_cmdline.split(" ")[0]
        self.assertEqual(ps_cmdline, psutil_cmdline)

    def test_nice(self):
        ps_nice = ps("ps --no-headers -o nice -p %s" % self.pid)
        psutil_nice = psutil.Process().nice()
        self.assertEqual(ps_nice, psutil_nice)

    def test_num_fds(self):
        # Note: this fails from time to time; I'm keen on thinking
        # it doesn't mean something is broken
        def call(p, attr):
            args = ()
            attr = getattr(p, name, None)
            if attr is not None and callable(attr):
                if name == 'rlimit':
                    args = (psutil.RLIMIT_NOFILE,)
                attr(*args)
            else:
                attr

        p = psutil.Process(os.getpid())
        failures = []
        ignored_names = ['terminate', 'kill', 'suspend', 'resume', 'nice',
                         'send_signal', 'wait', 'children', 'as_dict']
        if LINUX and get_kernel_version() < (2, 6, 36):
            ignored_names.append('rlimit')
        if LINUX and get_kernel_version() < (2, 6, 23):
            ignored_names.append('num_ctx_switches')
        for name in dir(psutil.Process):
            if (name.startswith('_') or name in ignored_names):
                continue
            else:
                try:
                    num1 = p.num_fds()
                    for x in range(2):
                        call(p, name)
                    num2 = p.num_fds()
                except psutil.AccessDenied:
                    pass
                else:
                    if abs(num2 - num1) > 1:
                        fail = "failure while processing Process.%s method " \
                               "(before=%s, after=%s)" % (name, num1, num2)
                        failures.append(fail)
        if failures:
            self.fail('\n' + '\n'.join(failures))

    @unittest.skipUnless(os.path.islink("/proc/%s/cwd" % os.getpid()),
                         "/proc fs not available")
    def test_cwd(self):
        self.assertEqual(os.readlink("/proc/%s/cwd" % os.getpid()),
                         psutil.Process().cwd())


@unittest.skipUnless(POSIX, "not a POSIX system")
class TestSystemAPIs(unittest.TestCase):
    """Test some system APIs."""

    @retry_before_failing()
    def test_pids(self):
        # Note: this test might fail if the OS is starting/killing
        # other processes in the meantime
        if SUNOS:
            cmd = ["ps", "-A", "-o", "pid"]
        else:
            cmd = ["ps", "ax", "-o", "pid"]
        p = get_test_subprocess(cmd, stdout=subprocess.PIPE)
        output = p.communicate()[0].strip()
        assert p.poll() == 0
        if PY3:
            output = str(output, sys.stdout.encoding)
        pids_ps = []
        for line in output.split('\n')[1:]:
            if line:
                pid = int(line.split()[0].strip())
                pids_ps.append(pid)
        # remove ps subprocess pid which is supposed to be dead in meantime
        pids_ps.remove(p.pid)
        pids_psutil = psutil.pids()
        pids_ps.sort()
        pids_psutil.sort()

        # on OSX ps doesn't show pid 0
        if OSX and 0 not in pids_ps:
            pids_ps.insert(0, 0)

        if pids_ps != pids_psutil:
            difference = [x for x in pids_psutil if x not in pids_ps] + \
                         [x for x in pids_ps if x not in pids_psutil]
            self.fail("difference: " + str(difference))

    # for some reason ifconfig -a does not report all interfaces
    # returned by psutil
    @unittest.skipIf(SUNOS, "test not reliable on SUNOS")
    @unittest.skipIf(TRAVIS, "test not reliable on Travis")
    def test_nic_names(self):
        p = subprocess.Popen("ifconfig -a", shell=1, stdout=subprocess.PIPE)
        output = p.communicate()[0].strip()
        if PY3:
            output = str(output, sys.stdout.encoding)
        for nic in psutil.net_io_counters(pernic=True).keys():
            for line in output.split():
                if line.startswith(nic):
                    break
            else:
                self.fail(
                    "couldn't find %s nic in 'ifconfig -a' output\n%s" % (
                        nic, output))

    @retry_before_failing()
    def test_users(self):
        out = sh("who")
        lines = out.split('\n')
        users = [x.split()[0] for x in lines]
        self.assertEqual(len(users), len(psutil.users()))
        terminals = [x.split()[1] for x in lines]
        for u in psutil.users():
            self.assertTrue(u.name in users, u.name)
            self.assertTrue(u.terminal in terminals, u.terminal)

    def test_pid_exists_let_raise(self):
        # According to "man 2 kill" possible error values for kill
        # are (EINVAL, EPERM, ESRCH). Test that any other errno
        # results in an exception.
        with mock.patch("psutil._psposix.os.kill",
                        side_effect=OSError(errno.EBADF, "")) as m:
            self.assertRaises(OSError, psutil._psposix.pid_exists, os.getpid())
            assert m.called

    def test_os_waitpid_let_raise(self):
        # os.waitpid() is supposed to catch EINTR and ECHILD only.
        # Test that any other errno results in an exception.
        with mock.patch("psutil._psposix.os.waitpid",
                        side_effect=OSError(errno.EBADF, "")) as m:
            self.assertRaises(OSError, psutil._psposix.wait_pid, os.getpid())
            assert m.called

    def test_os_waitpid_eintr(self):
        # os.waitpid() is supposed to "retry" on EINTR.
        with mock.patch("psutil._psposix.os.waitpid",
                        side_effect=OSError(errno.EINTR, "")) as m:
            self.assertRaises(
                psutil._psposix.TimeoutExpired,
                psutil._psposix.wait_pid, os.getpid(), timeout=0.01)
            assert m.called

    def test_os_waitpid_bad_ret_status(self):
        # Simulate os.waitpid() returning a bad status.
        with mock.patch("psutil._psposix.os.waitpid",
                        return_value=(1, -1)) as m:
            self.assertRaises(ValueError,
                              psutil._psposix.wait_pid, os.getpid())
            assert m.called

    def test_disk_usage(self):
        def df(device):
            out = sh("df -k %s" % device).strip()
            line = out.split('\n')[1]
            fields = line.split()
            total = int(fields[1]) * 1024
            used = int(fields[2]) * 1024
            free = int(fields[3]) * 1024
            percent = float(fields[4].replace('%', ''))
            return (total, used, free, percent)

        tolerance = 4 * 1024 * 1024  # 4MB
        for part in psutil.disk_partitions(all=False):
            usage = psutil.disk_usage(part.mountpoint)
            try:
                total, used, free, percent = df(part.device)
            except RuntimeError as err:
                # see:
                # https://travis-ci.org/giampaolo/psutil/jobs/138338464
                # https://travis-ci.org/giampaolo/psutil/jobs/138343361
                if "no such file or directory" in str(err).lower() or \
                        "raw devices not supported" in str(err).lower():
                    continue
                else:
                    raise
            else:
                self.assertAlmostEqual(usage.total, total, delta=tolerance)
                self.assertAlmostEqual(usage.used, used, delta=tolerance)
                self.assertAlmostEqual(usage.free, free, delta=tolerance)
                self.assertAlmostEqual(usage.percent, percent, delta=1)


if __name__ == '__main__':
    run_test_module_by_name(__file__)
