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

# lve_stats2_lib.py - lve-stats library for cloudlinux-config library

# 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 os
import subprocess

from clcommon.clexception import FormattedException
from clcommon.utils import mod_makedirs

from .clconfig_utils import (
    boolean_to_yes_no,
    is_positive_int,
    min_num_notify_converter,
    repack_dict,
    str_to_boolean,
    time_convertor_to_dict,
    time_unit_to_letter,
)


class LveStats2Exception(FormattedException):
    pass


StatsNotifierDir = '/etc/sysconfig/lvestats.config'
StatsNotifierConfig = StatsNotifierDir + '/StatsNotifier.cfg'

notify_dict = {'NOTIFY_ADMIN': 'notifyAdmin',
               'NOTIFY_RESELLER': 'notifyResellers',
               'NOTIFY_CUSTOMER': 'notifyCustomers',
               'NOTIFY_INCLUDE_RESELLER_CUSTOMER': 'notifyResellerCustomers'}

faults_dict = {'NOTIFY_MEMORY': 'mem',
               'NOTIFY_IOPS': 'iops',
               'NOTIFY_NPROC': 'nproc',
               'NOTIFY_IO': 'io',
               'NOTIFY_EP': 'concurrentConnections',
               'NOTIFY_CPU': 'cpu'}

email_notify_dict = {'NOTIFY_FROM_EMAIL': 'notifyFromEmail',
                     'REPORT_ADMIN_EMAIL': 'reportAdminMail',
                     'NOTIFY_FROM_SUBJECT': 'notifySubject',
                     'NOTIFY_CHARSET_EMAIL': 'notifyCharset'}

number_notify_dict = {'NOTIFY_MIN_FAULTS_USER': 'user',
                      'NOTIFY_MIN_FAULTS_ADMIN': 'admin'}

notify_time_dict = {'NOTIFY_INTERVAL_ADMIN': 'admin',
                    'NOTIFY_INTERVAL_USER': 'user'}


# For unit tests
def _open(file_name, mode='r'):
    return open(file_name, mode=mode, encoding='utf-8')


def get_notification(reseller=None):
    """
    Retrieves lve-stats2 notifications parameters
    :param str reseller: reseller name, if we want notifications parameters for a reseller
    :return: dict. For example:
        {'faultsNotification': {'notifyResellerCustomers': True,
                                'notifyResellers': True,
                                'minimumNumberOfFaultsToNotify': {'admin': 0, 'user': 0},
                                'notifyAdmin': True,
                                'notify': {'admin': {'unitOfTime': 'hours', 'period': 12},
                                           'user': {'unitOfTime': 'hours', 'period': 12}
                                          },
                                'faultsToInclude': {'mem': True, 'iops': False, 'io': False,
                                                    'nproc': False, 'concurrentConnections': False,
                                                    'cpu': True},
                                'notifyCustomers': False
                               }
        }
    """
    config_path = StatsNotifierConfig
    if not os.path.exists(config_path):
        return {}

    try:
        f = _open(config_path)
        config = f.readlines()
        f.close()
    except (IOError, OSError) as e:
        raise LveStats2Exception({'message': "%(lvestats_cfg)s read error: " + str(e),
                                  'context': {'lvestats_cfg': config_path}}) from e

    config_dict = {}
    for line in config:
        # skip comments and empty lines
        if line.startswith('#') or line.strip() == '':
            continue
        key, value = line.split('=')
        config_dict[key] = value.strip()

    notify_d = notify_dict
    faults_d = faults_dict
    number_notify_d = number_notify_dict
    notify_time_d = notify_time_dict

    faults_notification_dict = repack_dict(notify_d, config_dict, str_to_boolean)
    faults_include_dict = repack_dict(faults_d, config_dict, str_to_boolean)
    min_num_notify = repack_dict(number_notify_d, config_dict, min_num_notify_converter, default=1)
    period_notify = repack_dict(notify_time_d, config_dict, time_convertor_to_dict)
    email_settings = repack_dict(email_notify_dict, config_dict, str, default=None)

    faults_notification_dict['faultsToInclude'] = faults_include_dict
    faults_notification_dict['minimumNumberOfFaultsToNotify'] = min_num_notify
    faults_notification_dict['notify'] = period_notify
    faults_notification_dict['email'] = email_settings
    return {"faultsNotification": faults_notification_dict}


def set_notification(parameters_dict, reseller=None):
    """
    Sets lve-stats2 notifications parameters
    :param parameters_dict: Parametres to set. For example:
        {u'notifyResellers': True,
         u'faultsToInclude': {u'mem': True, u'iops': False, u'io': False, u'nproc': False,
                                u'concurrentConnections': False, u'cpu': True},
         u'minimumNumberOfFaultsToNotify': {u'admin': 0, u'user': 0},
         u'notifyAdmin': True,
         u'notify': {u'admin': {u'unitOfTime': u'hours', u'period': 12},
                     u'user': {u'unitOfTime': u'hours', u'period': 12}
                    },
         u'notifyResellerCustomers': True,
         u'notifyCustomers': False
        }
    :param str reseller: either reseller name or None
    """
    # Do nothing, if admin's lvestats2 notifier config not found
    # either parameters_dict is empty and we shouldn't change anything
    if not os.path.exists(StatsNotifierConfig) or len(parameters_dict) == 0:
        return

    notifier_params = {}

    config_path = StatsNotifierConfig
    notifier_params = get_notification()

    # create directory and empty config if not exists
    if not os.path.exists(os.path.dirname(config_path)):
        mod_makedirs(os.path.dirname(config_path), 0o755)
    if not os.path.exists(config_path):
        _open(config_path, 'w').close()

    # Read notifier config
    try:
        f = _open(config_path)
        config_lines = [line.strip() for line in f.readlines()]
        f.close()
    except (IOError, OSError) as e:
        raise LveStats2Exception({'message': "%(lvestats_cfg)s read error: " + str(e),
                                  'context': {'lvestats_cfg': StatsNotifierConfig}}) from e

    # Fill parameters to change lve-stats config

    faults_config_map = {'NOTIFY_CPU': (lambda x: boolean_to_yes_no(x), 'faultsToInclude/cpu'),
                         'NOTIFY_NPROC': (lambda x: boolean_to_yes_no(x), 'faultsToInclude/nproc'),
                         'NOTIFY_IO': (lambda x: boolean_to_yes_no(x), 'faultsToInclude/io'),
                         'NOTIFY_MEMORY': (lambda x: boolean_to_yes_no(x), 'faultsToInclude/mem'),
                         'NOTIFY_EP': (lambda x: boolean_to_yes_no(x), 'faultsToInclude/concurrentConnections'),
                         'NOTIFY_IOPS': (lambda x: boolean_to_yes_no(x), 'faultsToInclude/iops')}

    faults_config_map.update({
        'NOTIFY_INTERVAL_ADMIN': (lambda x, y: f"{is_positive_int(x)}{time_unit_to_letter(y)}",
                                  'notify/admin/period',
                                  'notify/admin/unitOfTime'),
        'NOTIFY_INTERVAL_USER': (lambda x, y: f"{is_positive_int(x)}{time_unit_to_letter(y)}",
                                  'notify/user/period',
                                  'notify/user/unitOfTime'),
        'NOTIFY_ADMIN': (lambda x: boolean_to_yes_no(x), 'notifyAdmin'),
        'NOTIFY_CUSTOMER': (lambda x: boolean_to_yes_no(x), 'notifyCustomers'),
        'NOTIFY_RESELLER': (lambda x: boolean_to_yes_no(x), 'notifyResellers'),
        'NOTIFY_INCLUDE_RESELLER_CUSTOMER': (lambda x: boolean_to_yes_no(x), 'notifyResellerCustomers'),
        'NOTIFY_MIN_FAULTS_ADMIN': 'minimumNumberOfFaultsToNotify/admin',
        'NOTIFY_MIN_FAULTS_USER': 'minimumNumberOfFaultsToNotify/user'})

    # Update dict with email parameters
    # If None is passed, line will be removed from config before writing it back to file
    faults_config_map.update({
        'NOTIFY_FROM_EMAIL': 'email/notifyFromEmail',
        'NOTIFY_FROM_SUBJECT': 'email/notifySubject',
        'REPORT_ADMIN_EMAIL': 'email/reportAdminMail',
        'NOTIFY_CHARSET_EMAIL': 'email/notifyCharset'})

    new_config = {}

    def get_val_by_path(path):
        path_parts = path.split('/')
        try:
            point = parameters_dict
            for part in path_parts:
                point = point[part]
        except KeyError:
            point = notifier_params['faultsNotification']
            for part in path_parts:
                point = point[part]
        return point

    for key, val in faults_config_map.items():
        try:
            if isinstance(val, str):
                new_config[key] = get_val_by_path(val)
            else:
                new_config[key] = val[0](*(get_val_by_path(x) for x in val[1:]))
        except KeyError:
            continue

    # to do not change iter object while iterate it
    config_to_write = [line.strip() for line in config_lines]
    try:
        for idx, line in enumerate(config_lines):
            # Pass comment and empty lines
            if line.startswith('#') or line.strip() == '':
                continue
            try:
                key, value = line.split('=')
            except ValueError as e:
                raise LveStats2Exception({
                    'message': '%(lvestats_cfg)s format error: ' + f'{idx + 1}: {line}',
                    'context': {'lvestats_cfg': config_path}}) from e
            if key in new_config:
                # Parameter must be changed
                config_to_write[idx] = f"{key}={new_config[key]}"
                # Remove used parameter
                del new_config[key]
    except (KeyError, IndexError) as e:
        raise LveStats2Exception({'message': "%(lvestats_cfg)s format error: " + str(e),
                                  'context': {'lvestats_cfg': config_path}}) from e
    # Add absent options
    for key, value in new_config.items():
        config_to_write.append(f"{key}={value}")

    # Email notifications are optional
    # They should be removed from config, if None value is passed
    def filter_config_lines(_line):
        if _line.startswith('#') or _line.strip() == '':
            return True
        _, _value = _line.split('=')
        return _value != 'None'

    config_to_write = list(filter(filter_config_lines, config_to_write))

    # Write config back to file
    try:
        with open(config_path, 'w', encoding='utf-8') as f:
            f.writelines('\n'.join(config_to_write))
    except (IOError, OSError) as e:
        raise LveStats2Exception({'message': "%(lvestats_cfg)s write error: " + str(e),
                                  'context': {'lvestats_cfg': config_path}}) from e
    # Restart lvestats server
    # /sbin/service lvestats reload
    subprocess.run('/sbin/service lvestats reload &>/dev/null &',
                   shell=True, executable='/bin/bash', check=False)