# -*- coding: utf-8 -*-

# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
from __future__ import print_function
from __future__ import absolute_import
from __future__ import division
from __future__ import unicode_literals
from future import standard_library
standard_library.install_aliases()
from builtins import *
import os
import pwd
import grp
import glob
import subprocess
import re
from clcommon import clconfpars

from itertools import chain
from collections import namedtuple

from cagefsctl import (
    MountpointConfig,
    DISABLE_ETCFS,
    get_cagefs_users,
    enabled_dir,
    disabled_dir,
    build_wrappers_dicts,
)
from cagefslib import CageFSException
from clcagefslib.selector.configure import is_ea4_enabled, read_cpanel_ea4_php_conf

cldiaglib_found = True
try:
    from cldiaglib import (
        runner,
        ChkResult,
        OK, FAILED, SKIPPED,
    )
except ImportError:
    cldiaglib_found = False
    # Possible result types
    OK = 'OK'
    FAILED = 'FAILED'
    SKIPPED = 'SKIPPED'
    INTERNAL_TEST_ERROR = 'INTERNAL_TEST_ERROR'
    ChkResult = namedtuple('ChkResult', [
        'res',          # One of predefined checker result types
        'msg',          # Resulting msg from this checker
    ])

def check_cagefs_mount_points_exists():
    # We don't check personal mounts because they could be virtual
    # and don't use read_only_mounts list because it's already in "mounts"
    mp_config = MountpointConfig(skip_errors=True, ignore_cache=True)

    missing = []
    for p in chain(mp_config.common_mounts,
                   mp_config.splitted_by_username_mounts,
                   mp_config.splitted_by_uid_mounts):
        t = p.strip()
        if not os.path.isdir(t):
            missing.append(t)

    if missing:
        return ChkResult(FAILED, 'There are missing mount points: {}'.format(missing))
    return ChkResult(OK, 'No missing mount points found')
check_cagefs_mount_points_exists.pretty_name = 'Check cagefs mount points exists'


def check_cagefs_enabled_users_isdir():
    if os.path.exists(enabled_dir) and not os.path.isdir(enabled_dir):
        return ChkResult(FAILED, "{} is not a directory".format(enabled_dir))
    return ChkResult(OK, '{} is fine'.format(enabled_dir))
check_cagefs_enabled_users_isdir.pretty_name = 'Check cagefs users.enabled is directory'


def check_cagefs_disabled_users_isdir():
    if os.path.exists(disabled_dir) and not os.path.isdir(disabled_dir):
        return ChkResult(FAILED, "{} is not a directory".format(disabled_dir))
    return ChkResult(OK, '{} is fine'.format(disabled_dir))
check_cagefs_disabled_users_isdir.pretty_name = 'Check cagefs users.disabled is directory'


def check_cagefs_disabled_etcfs_exists():
    if not os.path.exists(DISABLE_ETCFS):
        return ChkResult(FAILED, "{} doesn't exists".format(DISABLE_ETCFS))
    return ChkResult(OK, '{} exists'.format(DISABLE_ETCFS))
check_cagefs_disabled_etcfs_exists.pretty_name = 'Check cagefs disable.etcfs exists'


def get_cagefs_user_for_test(groups, all_enabled_users):
    """
    Filter out users that are in super groups and
    return username and uid of cagefs user for test
    :param groups: list of super groups
    :type groups: list of str
    :param all_enabled_users: list of cagefs users to filter
    :type all_enabled_users: list of str
    :rtype tuple (user, uid) or (None, None) when user not found
    """
    super_gids = set()   # set of gids of super groups from pam_lve config
    super_uids = set()   # set of uids of members of super groups
    re_pattern = re.compile('^cldiaguser_[a-f0-9]{21}$')
    for group in groups:
        try:
            g = grp.getgrnam(group)
        except KeyError:
            continue
        super_gids.add(g.gr_gid)
        for user in g.gr_mem:
            try:
                p = pwd.getpwnam(user)
            except KeyError:
                continue
            super_uids.add(p.pw_uid)
    for user in all_enabled_users:
        # LU-1893: skip cldiag test user
        if re_pattern.match(user):
            continue
        try:
            p = pwd.getpwnam(user)
        except KeyError:
            continue
        uid = p.pw_uid
        gid = p.pw_gid
        if gid in super_gids or uid in super_uids:
            continue
        return user, uid
    return None, None


def check_users_can_enter_cagefs():
    try:
        all_enabled_users = get_cagefs_users(raise_exception=True)
    except CageFSException:
        return ChkResult(SKIPPED, 'No users with cagefs enabled')
    if not all_enabled_users:
        return ChkResult(SKIPPED, 'No users with cagefs enabled')

    try:
        cfg = clconfpars.parse_pam_lve_config('/etc/pam.d/su')
    except (IOError, ValueError) as e:
        return ChkResult(FAILED, 'Error parsing /etc/pam.d/su config file {}'.format(e))
    if cfg is None:
        return ChkResult(FAILED, 'pam_lve configuration is not found in /etc/pam.d/su config file')

    user, uid = get_cagefs_user_for_test(cfg.groups, all_enabled_users)
    if user is None:
        return ChkResult(SKIPPED, 'No users with cagefs enabled (all enabled users are in super group)')

    inner = ('echo -n "Logged in as: $(whoami) - $(id -u) "; '
             '[ "$(id -u)" == "{0}" ] && ls /var/.cagefs').format(uid)
    cmd = """unset BASH_ENV; su '{0}' -s /bin/bash -c '{1}'""".format(user, inner)
    try:
        subprocess.check_output(cmd, stderr=subprocess.STDOUT,
                                shell=True, executable='/bin/bash', text=True).strip()
    except subprocess.CalledProcessError as e:
        return ChkResult(FAILED, '{}; Output was: "{}"'.format(e, e.output.strip()))
    return ChkResult(OK, 'Several tested users really can enter cagefs')
check_users_can_enter_cagefs.pretty_name = 'Check cagefs users can enter cagefs'


def check_proxy_commands_configs_are_parsable():
    try:
        # This will load all "*.proxy.commands" under the hood.
        # Currently we just try to parse them and expect that some exception
        # will be raised if syntax is invalid or files can't be loaded for
        # any reason.
        # More strict validation should be implemented in cagefsctl itself
        build_wrappers_dicts(raise_exception=True)
    except Exception as e:
        return ChkResult(
            FAILED,
            'Proxy commands config parsing error: "{}"'.format(repr(e))
        )
    return ChkResult(OK, 'Syntax looks fine. Files are parsable')
check_proxy_commands_configs_are_parsable.pretty_name = 'Check cagefs proxy commands configs are parsable'


def check_all_virt_mp_files_syntax():
    wrong = []
    files = glob.glob('/var/cagefs/*/*/virt.mp')

    if not files:
        return ChkResult(SKIPPED, 'No virt.mp files found')

    for virt_mp in files:
        with open(virt_mp, 'rt') as f:
            conf = f.read()

        # virt.mp files shouldn't be empty if exists
        if len(conf) == 0:
            wrong.append(virt_mp)
            continue

        # files shouldn't start with sub-directory definitions,
        # at least one parent should be first, so:
        if conf[0] == '@':
            wrong.append(virt_mp)

    if wrong:
        return ChkResult(FAILED, wrong)
    return ChkResult(OK, 'virt.mp files syntax is fine')
check_all_virt_mp_files_syntax.pretty_name = 'Check cagefs virt.mp files syntax'


def check_multiphp_system_default():
    def php_selector_is_disabled():
        try:
            f = open('/var/cpanel/cpanel.config', 'r')
            result = 'lve_hide_selector=1\n' in f
            f.close()
        except IOError:
            return False
        return result
    if is_ea4_enabled() and not php_selector_is_disabled():
        conf = read_cpanel_ea4_php_conf()
        if conf:
            try:
                # get default system php version selected via MultiPHP Manager in cPanel WHM
                default_php = conf['default']
                # LVEMAN-1170
                if not default_php.startswith('ea-php'):
                    return ChkResult(FAILED, 'Choose one of ea-php versions instead of alt-php in cPanel MultiPHP Manager for PHP Selector to start working.')
            except KeyError:
                return ChkResult(FAILED, 'Cannot get MultiPHP system default version')
    return ChkResult(OK, 'MultiPHP system default PHP version is NOT alt-php. PHP Selector should work normally.')
check_multiphp_system_default.pretty_name = 'Check MultiPHP system default php version'


CAGEFS_CHECKERS = (
    check_cagefs_mount_points_exists,
    check_cagefs_enabled_users_isdir,
    check_cagefs_disabled_users_isdir,
    check_cagefs_disabled_etcfs_exists,
    check_users_can_enter_cagefs,
    check_proxy_commands_configs_are_parsable,
    check_all_virt_mp_files_syntax,
    check_multiphp_system_default,
)


def run_tests():
    errors = []
    output = []
    for f in CAGEFS_CHECKERS:
        try:
            chk_res = f()
            res, details = chk_res.res, chk_res.msg
        except Exception as e:
            res, details = INTERNAL_TEST_ERROR, repr(e)
        if res == OK:
            output.append("{}...\n{}\n".format(f.__name__, res))
        else:
            if res not in (SKIPPED,):
                errors.append(res)
            output.append("{}...\n{}: {}\n".format(f.__name__, res, details))
    return errors, output


def check():
    if os.geteuid() != 0:
        print('This script should be run by root user')
        exit(1)
    if cldiaglib_found:
        runner(CAGEFS_CHECKERS)
    else:
        print('*** Starting sanity check ***\n')
        errors, out = run_tests()
        print('\n'.join(out))
        print('*** There are {} errors ***'.format(len(errors)))
        if errors:
            exit(2)