# coding=utf-8
#
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2021 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENCE.TXT
#
import logging
import os
import subprocess
from contextlib import contextmanager
from typing import Iterable  # NOQA

import psutil

from .constants import CRASH_LOG_PATH
from .exceptions import PackageMissingError


@contextmanager
def atomic_write(filepath, fsync=True):
    """ Writeable file object that atomically updates a file (using a temporary file).

    :param filepath: the file path to be opened
    :param fsync: whether to force write the file to disk
    """

    tmppath = filepath + '.tmp'
    try:
        with open(tmppath, 'w', encoding='utf-8') as f:
            yield f
            if fsync:
                f.flush()
                os.fsync(f.fileno())
        os.rename(tmppath, filepath)
    finally:
        try:
            os.remove(tmppath)
        except (IOError, OSError):
            pass


def is_background_process_running():
    """
    Detects if the process installing modules is running in the background.
    """

    def _is_wizard_cmdline(cmdline):
        # type: (Iterable[str]) -> bool
        return (
            {'/usr/sbin/cloudlinux-wizard', 'install', '--no-async'} <= set(cmdline)
            or {'/sbin/cloudlinux-wizard', 'install', '--no-async'} <= set(cmdline)
        )

    for proc in psutil.process_iter():
        # cmdline example:
        # ['/opt/cloudlinux/venv/bin/python3',
        #  'usr/sbin/cloudlinux-wizard',
        #  '--json', 'install', '--json-data', '{json obj}']
        try:
            cmdline = list(proc.cmdline())
        except psutil.NoSuchProcess:
            continue
        if _is_wizard_cmdline(cmdline):
            return True
    return False


def run_background(cmd):
    log_crash = open(CRASH_LOG_PATH, 'w', encoding='utf-8')  # pylint: disable=consider-using-with
    return subprocess.Popen(
        cmd,
        stdin=subprocess.DEVNULL,
        stdout=log_crash,
        stderr=log_crash
    )


def installed_interpreters_list(interpreter):
    try:
        from clselect.clselectctl import interpreter_versions_short_summary  # pylint: disable=import-outside-toplevel
    except ImportError as e:
        raise PackageMissingError('lvemanager') from e
    return interpreter_versions_short_summary(interpreter)


def convert_package_version(version, version_size):
    """
    Format version string
    e.g:
    3.6.0 -> 3.6 if version size = 2
    9.11.3 -> 9 if version size = 1
    :param version given version to convert
    :param version_size expected size of result version string
    """
    return '.'.join(version.split('.')[:version_size])


def setup_logger(logger_name, log_file):
    """
    Logger setup for all modules
    :return:
    """
    app_logger = logging.getLogger(logger_name)
    app_logger.setLevel(logging.INFO)
    try:
        fh = logging.FileHandler(log_file)
    except IOError:
        pass
    else:
        fh.formatter = logging.Formatter(
            '[%(levelname)s | %(asctime)s]: %(message)s')
        app_logger.addHandler(fh)
    return app_logger