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

# clquota.py - module for interfacing with cl-quota utility for get/set user's quotas
#
# 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

import json
from typing import Dict, Optional, Tuple

from clcommon.clexception import FormattedException
from clcommon.utils import ExternalProgramFailed, run_command
from cllimits.lib import exec_utility
from cllimits.lib.utils import is_quota_active, is_quota_supported


class ClQuotaException(FormattedException):
    pass


class UnexpectedClQuotaError(ClQuotaException):
    """
    Raised when we get output from cl-quota
    that cannot be parsed properly.
    """
    def __init__(self, raw_response=None):
        broken_exc_message = {'message': "Unexpected response got from %(util)s. "
                                         "Raw response from cl-quota: '%(raw_response)s'."
                                         "Please, contact CloudLinux support for help in resolving this issue.",
                              'context': {'util': 'Quota', 'raw_response': raw_response}}
        super().__init__(broken_exc_message)


class QuotaDisabledException(ClQuotaException):
    """
    Raised when quotas are disabled in system globally.
    """
    def __init__(self):
        disabled_exc_message = {'message': "%(util)s is disabled",
                                'context': {'util': 'Quota'}}
        super().__init__(disabled_exc_message)


class ClQuotaLib:
    _CL_QUOTA_PATH = '/usr/bin/cl-quota'
    _REPQUOTA_PATH = '/usr/sbin/repquota'

    def __init__(self):
        # inodes limits data
        # uid --> (soft_limit, hard_limit)
        self._inode_user_limits: Optional[Dict[str, Tuple[str, str]]] = None
        self._inode_package_dict: Optional[Dict[str, Tuple[str, str]]] = None
        # Check if quota is supported
        self._is_clquota_present = None
        # Check if quota is activated
        self._is_clquota_activated = None

    def is_clquota_present(self):
        """
        Get quota presence flag
        :return: True/False - quotas present/not present
        """
        if self._is_clquota_present is None:
            self._is_clquota_present = is_quota_supported(self._CL_QUOTA_PATH, self._REPQUOTA_PATH)
        return self._is_clquota_present

    def is_clquota_activated(self):
        """
        Get quota activated flag
        :return: True/False - quotas activeted/not activeted
        """
        if self._is_clquota_activated is None:
            self._is_clquota_activated = is_quota_active(self._CL_QUOTA_PATH, self._REPQUOTA_PATH)
        return self._is_clquota_activated

    def get_inodes_limits_by_uid(self, user_id):
        """
        Retrive inodes limits by uid
        :param user_id: Supplied uid
        :return: cortege (soft_limit, hard_limit). (None, None) if governor not present or error
        """
        # Load inodes data if need
        self._load_users_info()
        uid = str(user_id)
        if uid in self._inode_user_limits:
            return self._inode_user_limits[uid]
        return self._inode_user_limits['0']

    def set_user_inodes_limits(self, uid, limits, force=False):
        """
        Set inodes limits for user uid
        :param: int uid: user id
        :param: list limits: new inodes limits
        :param: bool force: save limits if even they are equal to defaults
        :return: None
        """
        self._load_users_info()
        if not isinstance(uid, int) or uid < 0:
            exc_message = {'message': "User id '%(uid)s' isn't a positive integer",
                           'context': {'uid': uid}}
            raise ClQuotaException(exc_message)
        if limits == "unlimited":
            limits = ["unlimited"] * 2
        elif limits == "default":
            limits = ["default"] * 2
        else:
            if type(limits) in [tuple, list]:
                pass
            elif len(limits.split(',')) == 2:
                limits = limits.split(',')
            else:
                exc_message = {'message': "Limits %(limits)s aren't acceptable.",
                               'context': {'limits': limits}}
                raise ClQuotaException(exc_message)

            for limit in limits:
                try:
                    if limit != "default":
                        limit = int(limit)
                        if limit < 0:
                            raise ValueError()
                except ValueError as e:
                    exc_message = {'message': "Limit value '%(limit)s' isn't a positive integer or string %(default)s",
                                   'context': {'limit': limit, 'default': 'default'}}
                    raise ClQuotaException(exc_message) from e
        cmd = [self._CL_QUOTA_PATH,
               f'--user-id={uid}',
               f'--soft-limit={limits[0]}',
               f'--hard-limit={limits[1]}']
        if force:
            cmd.append("--force")
        try:
            run_command(cmd)
        except ExternalProgramFailed as e:
            raise ClQuotaException(str(e)) from e

    def set_user_inodes_limits_unlimited(self, uid):
        """
        Set unlimited inodes limits for user uid
        :param: int uid: user id
        :return: None
        """
        self.set_user_inodes_limits(uid, "unlimited")

    def reset_user_inodes_limits(self, uid):
        """
        Set default inodes limits for user uid
        :param: int uid: user id
        :return: None
        """
        self.set_user_inodes_limits(uid, "default")

    def _load_users_info(self):
        """
        Loads users info from cl-quota
        :return: None
        """
        # Exit if cl-quota data already loaded
        if self._inode_user_limits is not None:
            return
        # Exit if cl-quota not present or cl-quota error
        if not self.is_clquota_present() or not self.is_clquota_activated():
            raise QuotaDisabledException()
        try:
            data = self._get_quotas(['--json'])
        except ClQuotaException:
            self._inode_user_limits = None
            raise
        self._inode_user_limits = {}
        for uid, limits in data.items():
            self._inode_user_limits[uid] = (int(limits[1][1]), int(limits[2][1]))

        if '0' not in self._inode_user_limits:
            self._inode_user_limits = None
            exc_message = {'message': "There is no %(what)s found in %(where)s",
                           'context': {'what': 'default settings', 'where': f'{self._CL_QUOTA_PATH} output'}}
            raise ClQuotaException(exc_message)

    def _get_quotas(self, command):
        # Get all cl-quota limits and parse them to self._inodes_limits
        _, s_quota_limits = exec_utility(self._CL_QUOTA_PATH, command)
        try:
            data = json.loads(s_quota_limits)
        except (TypeError, ValueError) as e:
            raise UnexpectedClQuotaError(raw_response=s_quota_limits) from e
        if not data:
            raise UnexpectedClQuotaError()

        if data['result'] != 'success':
            raise ClQuotaException({
                'message': data['result'],
                'context': data.get('context', {}),
                'details': data.get('details')
            })
        return data['items']

    def reset_inodes_limits(self):
        """
        Reset inodes limits for all users to package limits
        :return:
        """
        if not self.is_clquota_present() or not self.is_clquota_activated():
            return
        exec_utility(self._CL_QUOTA_PATH, ['--sync'])

    def _load_packages_info(self):
        """
        Loads packages info from cl-quota
        :return: None
        """
        # Exit if cl-quota data already loaded
        if self._inode_package_dict is not None:
            return
        # Exit if cl-quota not present or cl-quota error
        if not self.is_clquota_present() or not self.is_clquota_activated():
            raise QuotaDisabledException()
        try:
            packages = self._get_quotas(['--json', '--all-package-limits'])
        except ClQuotaException:
            self._inode_package_dict = None
            raise
        self._inode_package_dict = {}
        for package, limits in packages.items():
            soft_limit = limits[1][1]
            if soft_limit == '-':
                soft_limit = 0
            else:
                soft_limit = int(soft_limit)

            hard_limit = limits[2][1]
            if hard_limit == '-':
                hard_limit = 0
            else:
                hard_limit = int(hard_limit)
            self._inode_package_dict[package] = {'soft': soft_limit, 'hard': hard_limit}

    def get_reseller_package_limits(self, package_name_arg):
        """
        Get inodes limits for supplied reseller and package
        :param package_name_arg: Package name. Only if reseller name is provided. If None - all packages
        :return: Packages limits dictionary: {package_name: { "soft": 100000, "hard": 200000 } }
        If package with supplied name not found, dictionary will be empty
        """
        self._load_packages_info()
        if not package_name_arg:
            # if package name not provided - return all packages
            return self._inode_package_dict
        # Package name provided
        if package_name_arg in self._inode_package_dict:
            return {package_name_arg: self._inode_package_dict[package_name_arg]}
        return {}

    def __set_error(self, param, package_name, err):
        return {'message': "%(what)s set error for package=%(package)s%(error)s",
                'context': {'what': param, 'package': package_name,
                            'error': f" [{err}]" if err else ""}}

    def set_reseller_package_limits(self, package_name, limits_to_set):
        """
        Set inodes limits for package
        Called from cloudlinux-packages set
        :param package_name: Package name
        :param limits_to_set: Limits to set: soft_limit,hard_limit
        :return: None
        """
        disabled_exc_message = {'message': "%(util)s is disabled",
                                'context': {'util': 'Quota'}}
        # Exit if cl-quota not present or cl-quota error
        if not self.is_clquota_present() or not self.is_clquota_activated():
            raise ClQuotaException(disabled_exc_message)
        limits = limits_to_set.split(',')
        if len(limits) != 2:
            # Argument error
            raise ClQuotaException({'message': "%(util)s argument error",
                                    'context': {'util': 'cl-quota'}})
        # set quotas limits
        cl_quota_cmd = [f'--package={package_name}',
                        f'--soft-limit={limits[0]}',
                        f'--hard-limit={limits[1]}']
        ret_code, stdout = exec_utility(self._CL_QUOTA_PATH, cl_quota_cmd)
        if ret_code != 0 or stdout:
            # Set limits error
            raise ClQuotaException(self.__set_error('Inodes limits', package_name, stdout))

    def set_package_limits_independently(self, package_name, limits):
        """
        Set inodes limits for package
        Called from cl-syncpkgs
        :param package_name: Package name
        :param limits: Limits to set: {"inodes_soft":1000, "inodes_hard":2000}
        :return: None
        """
        disabled_exc_message = {'message': "Quota is disabled"}
        # Exit if cl-quota not present or cl-quota error
        if not self.is_clquota_present() or not self.is_clquota_activated():
            raise ClQuotaException(disabled_exc_message)
        if len(limits) == 0:
            raise ClQuotaException({'message': "Unspecified limits for cl-quota"})
        if not set(limits) <= {'inodes_soft', 'inodes_hard'}:
            bad_limits = set(limits) - {'inodes_soft', 'inodes_hard'}
            raise ClQuotaException({'message': "Incorrect limits for cl-quota: %(bad_limits)s",
                                    'context': {'bad_limits': ', '.join(bad_limits)}})
        cl_quota_cmd = [f'--package={package_name}']
        if 'inodes_soft' in limits:
            cl_quota_cmd.append(f"--soft-limit={limits['inodes_soft']}")
        if 'inodes_hard' in limits:
            cl_quota_cmd.append(f"--hard-limit={limits['inodes_hard']}")
        ret_code, stdout = exec_utility(self._CL_QUOTA_PATH, cl_quota_cmd)
        if ret_code != 0 or stdout:
            raise ClQuotaException(self.__set_error('Inodes limits', package_name, stdout))