# -*- 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 base64
import os
import subprocess
import sys

import lvectllib
from clcommon.clpwd import ClPwd
from clcommon.const import Feature
from clcommon.cpapi import is_panel_feature_supported, list_users, userdomains


class DomainCollector:
    """
    Class for print panel users domain docroots.
    See LU-1751 for details
    """
    def __init__(self):
        self.is_not_in_lve = not bool(os.environ.get('DOM_COLL_RUNNING_IN_LVE'))
        self.is_not_limited_process = self.is_not_limited()
        self._clpwd = ClPwd()

    @staticmethod
    def is_not_limited():
        is_limited_by_lve = bool(os.environ.get('DOM_COLL_RUNNING_IN_LVE'))
        is_limited_by_nice = bool(os.environ.get('DOM_COLL_RUNNING_IN_NICE'))
        return not is_limited_by_lve and not is_limited_by_nice

    def _get_panel_user_names_list(self):
        """
        Get panel user names list
        :return: user names list
        """
        panel_uids_list = list(list_users().keys())
        panel_users_list = []
        for uid in panel_uids_list:
            try:
                name = self._clpwd.get_names(uid)[0]
                panel_users_list.append(name)
            except ClPwd.NoSuchUserException:
                pass
        return panel_users_list

    def _print_users_doc_roots_and_domains(self):
        """
        Method prints pair `domain,doc_root` for an each user on a server
        domain is encoded in punycode if it's needed
        doc_root is always encoded in base64
        """
        panel_users_list = self._get_panel_user_names_list()
        for username in panel_users_list:
            try:
                for domain, doc_root in userdomains(username):
                    encoded_doc_root = base64.b64encode(
                        doc_root.encode('utf-8'),
                    ).decode('utf-8')
                    print(f'{domain},{encoded_doc_root}')
            except Exception:
                # userdomains has very various implementations
                # in cpapi plugins for different panels,
                #  so we catch common Exception instead separate exceptions
                pass

    def run(self):
        if self.is_not_limited_process:
            if is_panel_feature_supported(Feature.LVE):
                try:
                    rc = self._run_self_in_lve()
                    sys.exit(rc)
                except lvectllib.PyLveError as e:
                    error_msg = f'failed to run task in lve, error: {e}'
                    print(error_msg)
                    sys.exit(-1)
            else:
                rc = self._run_by_nice()
                sys.exit(rc)
        else:
            # We in LVE, collect docroots list
            self._print_users_doc_roots_and_domains()

    # TODO: we need this bicycle because method pylve.lve_enter_pid does not work properly (surprise!)
    # when we call lve_enter_pid, lve limits process only by cpu usage, other parameters are unlimited
    @staticmethod
    def _run_self_in_lve():
        """
        Run same command in lve and set environ RUNNING_IN_LVE=True
        in order to check it in child process.
        :return:
        """
        settings = lvectllib.make_liblve_settings(
            lvectllib.create_liblve_settings(
                ls_cpu=15,  # 15 percents of CPU (NOT core)
                ls_cpus=0,
                ls_memory_phy=1024 * 1024 ** 2  # 1gb
            )
        )
        with lvectllib.temporary_lve(settings) as lve_id:
            return subprocess.call(
                ['/bin/lve_suwrapper', '-n', str(lve_id), '/usr/bin/cloudlinux_domains_collector'],
                env=dict(os.environ, DOM_COLL_RUNNING_IN_LVE='1'))

    @staticmethod
    def _run_by_nice():
        return subprocess.call(
            ['/usr/bin/nice', '-n', '19',
             '/usr/bin/cloudlinux_domains_collector'],
            env=dict(
                os.environ,
                DOM_COLL_RUNNING_IN_NICE='1',
            )
        )