# -*- coding: utf-8 -*-
#
# This file is part of Glances.
#
# Copyright (C) 2019 Nicolargo <nicolas@nicolargo.com>
#
# Glances is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Glances is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

"""
Thresholds classes: OK, CAREFUL, WARNING, CRITICAL
"""

import sys
from functools import total_ordering


class GlancesThresholds(object):
    """Class to manage thresholds dict for all Glances plugins:
    key: Glances stats (example: cpu_user)
    value: Threasold* instance
    """

    threshold_list = ['OK', 'CAREFUL', 'WARNING', 'CRITICAL']

    def __init__(self):
        self.current_module = sys.modules[__name__]
        self._thresholds = {}

    def get(self, stat_name=None):
        """Return the threshold dict.
        If stat_name is None, return the threshold for all plugins (dict of Threshold*)
        Else return the Threshold* instance for the given plugin
        """
        if stat_name is None:
            return self._thresholds

        if stat_name in self._thresholds:
            return self._thresholds[stat_name]
        else:
            return {}

    def add(self, stat_name, threshold_description):
        """Add a new threshold to the dict (key = stat_name)"""
        if threshold_description not in self.threshold_list:
            return False
        else:
            self._thresholds[stat_name] = getattr(self.current_module,
                                                  'GlancesThreshold' + threshold_description.capitalize())()
            return True


# Global variable uses to share thresholds between Glances componants
glances_thresholds = GlancesThresholds()


@total_ordering
class _GlancesThreshold(object):

    """Father class for all other Thresholds"""

    def description(self):
        return self._threshold['description']

    def value(self):
        return self._threshold['value']

    def __repr__(self):
        return str(self._threshold)

    def __str__(self):
        return self.description()

    def __lt__(self, other):
        return self.value() < other.value()

    def __eq__(self, other):
        return self.value() == other.value()


class GlancesThresholdOk(_GlancesThreshold):

    """Ok Threshold class"""

    _threshold = {'description': 'OK',
                  'value': 0}


class GlancesThresholdCareful(_GlancesThreshold):

    """Careful Threshold class"""

    _threshold = {'description': 'CAREFUL',
                  'value': 1}


class GlancesThresholdWarning(_GlancesThreshold):

    """Warning Threshold class"""

    _threshold = {'description': 'WARNING',
                  'value': 2}


class GlancesThresholdCritical(_GlancesThreshold):

    """Warning Threshold class"""

    _threshold = {'description': 'CRITICAL',
                  'value': 3}