# 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
import errno
import os
import pwd
import re
import subprocess
import sys
import json
import shutil

from time import time
from typing import AnyStr, List, Dict, Optional  # NOQA
from pathlib import Path

from clcommon.clpwd import resolve_username_and_doc_root
from clcommon.cpapi import CP_NAME
from clcommon.cpapi.cpapiexceptions import NoDomain, NotSupported, IncorrectData
from clcommon.utils import mod_makedirs
from clsentry import init_sentry_client
from clsentry.utils import get_pkg_version

from .clselectprint import clprint
from .clselectexcept import ClSelectExcept


CAGEFS_ENTER_USER_BIN = '/sbin/cagefs_enter_user'
LVEMANDSN = "https://9713d1296f804031b058b8f2d789d7ac:8ddacae32d8246cf8b25cf826bf3fc0a@cl.sentry.cloudlinux.com/12"

def run_command(cmd, env_data=None):
    """
    Runs external process and returns output
    :param cmd: command and arguments as a list
    :param env_data
    :return string
    """
    try:
        output = subprocess.Popen(
            cmd,
            stdin=open('/dev/null'),
            stdout=subprocess.PIPE,
            stderr=subprocess.STDOUT,
            close_fds=True,
            env=env_data,
            text=True)
        std_out, std_err = output.communicate()
    except (OSError, IOError) as e:
        raise ClSelectExcept.FileProcessError(cmd[0], str(e))
    if output.returncode != 0:
        raise ClSelectExcept.ExternalProgramFailed(std_err or 'output of the command: %s\n%s' % (' '.join(cmd),
                                                                                                 std_out))
    return std_out


def run_command_full(cmd, env_data=None, preexec_fn=None, cwd=None):
    """
    Runs external process and returns output.
    Differs from subprocess.check_output, run_command above, and check_output below in that it does not
     throw an exception if process's return code != 0
    :param cmd: command and arguments as a list
    :param env_data
    :param preexec_fn: Pre-exec function. None if don't need
    :param cwd: Directory name to set as current
    :return Cortege: (ret_code, stdout, stderr)
    """
    try:
        process = subprocess.Popen(
            cmd,
            stdin=open('/dev/null'),
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            preexec_fn=preexec_fn,
            close_fds=True,
            cwd=cwd,
            env=env_data)
        std_out, std_err = process.communicate()
    except (OSError, IOError) as e:
        raise ClSelectExcept.FileProcessError(cmd[0], str(e))
    return process.returncode, std_out, std_err


def read_file_as_string(filename):
    """
    Reads file contents and returns it as a string
    """
    defaults_contents = ""
    try:
        f = open(filename)
        defaults_contents = f.read()
        f.close()
    except (OSError, IOError):
        pass
    return defaults_contents


def check_call(*args, **kwargs):
    check_output(*args, **kwargs)


def check_output(*args, **kwargs):
    """
    check_output(val1, val2, val3, arg4=val4)
    equivalent
    check_output(args=(val1, val2, val3), arg4=val4)
    or equivalent
    check_output(val1, args=(val2, val3), arg4=val4)
    DON'T USE check_output((val1, val2, val3), arg4=val4)
    :param tuple *args: arguments for command line
    :param dict **kwargs: parameters for subprocess.Popen
    :return str:
    """
    error = kwargs.pop('error', None)
    args_from_kwargs = kwargs.get('args')
    output = kwargs.pop('output', None)
    wait = kwargs.pop('wait', None)
    if args_from_kwargs:
        args += args_from_kwargs
        del kwargs['args']
    try:
        p = subprocess.Popen(args=args, stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE, text=True, **kwargs)
    except (OSError, IOError) as e:
        raise ClSelectExcept.FileProcessError(args[0], str(e))
    stdout, stderr = p.communicate()
    if output:
        output.write(stdout)
        output.close()
    if wait is not None:
        p.wait()
    if p.returncode:
        raise ClSelectExcept.ExternalProgramFailed(error or stderr or stdout)
    return stdout


def list_dirs(path):
    return [d for d in os.listdir(path)
            if os.path.isdir(os.path.join(path, d))]


def versioning(path, versions):
    yield path
    for major, minors in versions:
        yield path + str(major)
        for minor in minors:
            yield path + '.'.join(map(str, (major, minor)))


def mkdir_p(path):
    try:
        os.makedirs(path)
    except OSError as exc:
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise


def get_abs_rel(user, directory):
    """
    Returns absolute and relative to user's home directories paths,
    after eliminating all symlinks
    :param user: Unix user whose home contains the directory
    :param directory: The directory to obtain absolute and relative paths for
    """
    user_dir = os.path.realpath(pwd.getpwnam(user).pw_dir)
    abs_dir = os.path.realpath(os.path.join(user_dir, directory))
    rel_dir = s_partition(abs_dir, user_dir)[2].lstrip(os.sep)
    if not all((abs_dir, rel_dir)):
        raise ClSelectExcept.WrongData(
            "Directory '%s' not in user home ('%s')" % (directory, user_dir))
    return abs_dir, rel_dir


def in_cagefs():
    return os.path.isdir('/var/.cagefs')


# TODO: need move to clcommon
# safely open/close files in python2.4
# http://stackoverflow.com/questions/3770348/how-to-safely-open-close-files-in-python-2-4
# TODO: consider to remove this method and use builtin
def file_read(path, mode='r', errors=None):
    """
    read file and close
    :param path: file path
    :param mode: reading mode
    :return str:
    """
    data = None
    stream = open(path, mode=mode, errors=errors)
    try:
        data = stream.read()
    finally:
        stream.close()
    return data


def file_readlines(path, errors=None):
    """
    read litle file and close
    :param path:
    :return str:
    """
    data = []
    stream = open(path, errors=errors)
    try:
        data = stream.readlines()
    finally:
        stream.close()
    return data


def file_write(path, line, mode='w', errors=None):
    """
    write litle data to file and close
    :param path:
    :return str:
    """
    stream = open(path, mode, errors=errors)
    try:
        stream.write(line)
    finally:
        stream.close()


def file_writelines(path, lines, mode='w', errors=None):
    """
    write litle data to file and close
    :param path:
    :return str:
    """
    stream = open(path, mode, errors=errors)
    try:
        stream.writelines(lines)
    finally:
        stream.close()


def s_partition(s, sep):
    """
    str.partition for all python versions
    :param s:		string to parse
    :param sep:		separator to split by
    :return:		cortege - see str.partition function for python 2.5+
    """
    if sys.version_info[0] >= 2 and sys.version_info[1] >= 5:
        return s.partition(sep)
    # Python v2.4 and lower does not support str.partition, so emulating it
    s_parts = s.split(sep, 1)
    if len(s_parts) == 2:
        ret_cortege = (s_parts[0], sep, s_parts[1])
    else:
        ret_cortege = (s_parts[0], '', '')
    return ret_cortege


def grep(pattern, path):
    """
    find regex count in file
    """
    try:
        f = open(path, "r")
    except IOError:
        return None

    counter = 0
    regex = re.compile(pattern)
    for line in f:
        if regex.search(line):
            counter += 1

    f.close()
    return counter


def user_should_be_skipped(username):
    """
    Determines is user should be skipped in selectorctl work
    :param username: user name to check
    :return: True - user should be skipped, False - not
    """
    from clcommon.cpapi import is_admin
    # user is DA admin, pass it
    return is_admin(username)


def make_dir(dest_dir):
    if not os.path.isdir(dest_dir):
        try:
            mod_makedirs(dest_dir, 0o755)
        except (IOError, OSError) as e:
            print('Error: failed to create', dest_dir, ':', str(e))
            sys.exit(1)


def remove_file_or_dir(path):
    try:
        os.unlink(path)
    except OSError:
        pass
    if os.path.isdir(path):
        shutil.rmtree(path, True)


def make_symlink(src, dst):
    try:
        if os.path.islink(dst):
            if os.readlink(dst) != src:
                os.unlink(dst)
                os.symlink(src, dst)
        else:
            remove_file_or_dir(dst)
            os.symlink(src, dst)
    except OSError as e:
        print('Error: failed to create symlink', dst, '->', src, ':', str(e))
        sys.exit(1)


def pretty_json(data):
    return json.dumps(data, indent=4, separators=(',', ': '), sort_keys=True)


# TODO: we have the same safely_resolve_username_and_doc_root in selectorlib, need some refactoring
def safely_resolve_username_and_doc_root(user=None, domain=None, msg_format='text', pass_not_supported_panel=False):
    """
    Safely resolve username and doc_root by domain,
    or resolve document root by username,
    or resolve document root and username by effective uid
    :param pass_not_supported_panel: pass not supported panel for php selector
    :param msg_format: error messages' format (json or text)
    :param user: str -> name of unix user
    :param domain: str -> domain of panel user
    :return: tuple -> user, doc_root
    """

    result_user = user
    result_doc_root = None
    try:
        result_user, result_doc_root = resolve_username_and_doc_root(
            user=user,
            domain=domain,
        )
    except NoDomain:
        clprint.print_diag(
            msg_format,
            {
                'status': 'ERROR',
                'message': 'No domain found for user: {}, domain: {}'.format(user, domain)
            }
        )
        sys.exit(1)
    except NotSupported:
        if pass_not_supported_panel:
            pass
        else:
            clprint.print_diag(
                msg_format,
                {
                    'status': 'ERROR',
                    'message': 'NodeJs/Ruby/Python selector not supported for %s panel' % CP_NAME
                }
            )
            sys.exit(1)
    except IncorrectData:
        clprint.print_diag(
            msg_format,
            {
                'status': 'ERROR',
                'message': 'Domain %s is not owned by the user %s' % (domain, user)
            }
        )
        sys.exit(1)

    return result_user, result_doc_root


def get_using_realpath_keys(user, directory, config):
    """
    Transform all directories to realpath, compare and return config value
    :param user: str -> unix user - owner of the config
    :param directory: str -> wanted directory key
    :param config: dict -> config to get value from,
        should have directories as keys
    """
    abs_directory = get_abs_rel(user, directory)[0]
    for conf_dir in config:
        abs_conf_dir = get_abs_rel(user, conf_dir)[0]
        if abs_directory == abs_conf_dir:
            return config[conf_dir]

    raise KeyError(
        'Config does not contain directory: {}'.format(directory))


def delete_using_realpath_keys(user, directory, config):
    """
    Transform all directories to realpath, compare and remove directory key
    :param user: str -> unix user - owner of the config
    :param directory: str -> wanted directory key
    :param config: dict -> config to remove key from,
        should have directories as keys
    """
    abs_directory = get_abs_rel(user, directory)[0]
    removed_at_least_one = False
    config_keys = list(config.keys())
    for conf_dir in config_keys:
        abs_conf_dir = get_abs_rel(user, conf_dir)[0]
        if abs_directory == abs_conf_dir:
            del config[conf_dir]
            removed_at_least_one = True
    if not removed_at_least_one:
        raise KeyError(
            'Config does not contain directory: {}'.format(directory))


def realpaths_are_equal(user, path1, path2):
    """
    Checks that two paths in user home directory are the same after
    stripping symlinks
    :param user: Unix user whose home directory contains both paths
    :type path1: str
    :type path2: str
    :return: True if paths are canonically the same otherwise False
    :rtype: bool
    """
    return get_abs_rel(user, path1)[0] == get_abs_rel(user, path2)[0]


def run_process_in_cagefs(user, path_to_utility, args_for_utility, env_vars=None):
    # type: (AnyStr, AnyStr, List[AnyStr], Optional[Dict[AnyStr, AnyStr]]) -> Dict[AnyStr, AnyStr, int]
    """
    Run any process using the utility cagefs_enter_user
    """
    result = {}

    # there are cases when we need to store some env vars
    # (e.g HOME when calling pip during import)
    if not env_vars:
        env_vars = {}
    cmd = [CAGEFS_ENTER_USER_BIN, user, path_to_utility] + args_for_utility
    process = subprocess.Popen(cmd, env=env_vars,
                               stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE,
                               text=True)
    stdout, _ = process.communicate()
    retcode = process.returncode
    # contition `retcode > 128` because in lve-wrappers:
    # if (WIFSIGNALED(status)) {
    #     exit(WTERMSIG(status) + 128);
    # }
    if not stdout and retcode > 128:
        stdout = {
            'details': 'User\'s process "{}" failed and didn\'t return anything. It could mean that user '
                       'has too small limit of PMEM for running of cloudlinux-selector. Please, '
                       'increase the limit to user and try run process again'.format(path_to_utility),
            'result': 'error',
            'timestamp': time(),
        }
    else:
        stdout = stdout.strip()
    result['output'] = stdout
    result['returncode'] = retcode
    result['failed'] = True if retcode else False
    return result


def is_imunify_using_python(version: str) -> bool:
    """
    Check if python version is used by imunify packages
    The algorithm is as follows:
    - Verify if imunify services are installed
    - Check if shebang contains the path to the specified Python version being checked
    - If shebang contains the path to the imunify virtual environment,
      determine the Python version it is based on by reading a symlink
    """
    # Init sentry for this function
    sentry_client = init_sentry_client(
        'lvemanager',
        release=get_pkg_version('lvemanager'),
        dsn=LVEMANDSN,
        handle=False
    )

    alt_path = f'/opt/alt/python{version.replace(".", "")}'
    imunify_venv_path = '/opt/imunify360/venv'
    imunify_service = Path('/usr/bin/imunify-service')
    if not imunify_service.is_file():
        return False

    try:
        with open(imunify_service) as f:
            first_line = f.readline()

        if not first_line.startswith('#!'):
            raise Exception(f'ERROR: "{imunify_service}" doesn\'t have a shebang')

        if alt_path in first_line:
            return True

        if imunify_venv_path in first_line:
            venv_python_bin = Path(first_line.lstrip('#!').strip())
            python_bin = venv_python_bin.readlink()
            if alt_path in str(python_bin):
                return True
    except:
        sentry_client.captureException()

    return False


def demote(user: str):
    """
    Drops to user
    """
    user_pwd = pwd.getpwnam(user)

    def func():
        os.setgid(user_pwd.pw_gid)
        os.setuid(user_pwd.pw_uid)
        os.environ['USER'] = user
        os.environ['HOME'] = user_pwd.pw_dir

    return func


def apply_for_at_least_one_user(func, users, exception_type, *args, **kwargs):
    caught_exception = None
    is_handled = False

    for user_alias in users:
        try:
            result = func(user_alias, *args, **kwargs)
        except exception_type as e:
            caught_exception = e
        else:
            is_handled |= True

    if not is_handled:
        raise caught_exception

    return result