#  -*- coding: utf-8 -*-
# *****************************************************************************
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program 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 General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# Module authors:
#   Markus Zolliker <markus.zolliker@psi.ch>
#
# *****************************************************************************

import os
from os.path import dirname, join
import mlzlog
from secop.lib import getGeneralConfig


OFF = 99

LOG_LEVELS = dict(mlzlog.LOGLEVELS, off=OFF)
LEVEL_NAMES = {v: k for k, v in LOG_LEVELS.items()}
log = None
rootlogdir = None


def checkLevel(level):
    try:
        if isinstance(level, str):
            return LOG_LEVELS[level.lower()]
        if level in LEVEL_NAMES:
            return level
    except KeyError:
        pass
    raise ValueError('%r is not a valid level' % level)


def initLogging(loglevel='info'):
    global log, rootlogdir  # pylint: disable-global-statement

    loglevel = checkLevel(loglevel)
    genConfig = getGeneralConfig()
    rootname = genConfig.get('rootname', 'secop')
    logdir = genConfig.get('logdir')
    rootlogdir = join(logdir, rootname)
    mlzlog.initLogging(rootname, 'debug', logdir)
    for hdl in mlzlog.log.handlers:
        hdl.setLevel(loglevel)
    return mlzlog.log


class ComlogHandler(mlzlog.LogfileHandler):
    """handler for logging communication

    communication is
    """

    def format(self, record):
        return '%s %s' % (self.formatter.formatTime(record), record.getMessage())

    def doRollover(self):
        super().doRollover()
        max_days = getGeneralConfig().get('comlog_days', 31)
        # keep only the last max_days files
        with os.scandir(dirname(self.baseFilename)) as it:
            files = sorted(entry.path for entry in it if entry.name != 'current')
        for filepath in files[-max_days:]:
            os.remove(filepath)


def add_comlog_handler(modobj):
    global rootlogdir  # pylint: disable-global-statement
    comlog = getGeneralConfig().get('comlog')
    if comlog:
        comlog = join(rootlogdir, comlog)
        modobj.log.addHandler(ComlogHandler(comlog, modobj.name))


class RemoteLogHandler(mlzlog.Handler):
    """handler for remote logging"""
    def __init__(self, modobj):
        super().__init__()
        self.subscriptions = {}  # dict [conn] of level
        self.modobj = modobj
        self.modobj.log.addHandler(self)
        self.used_by = set()

    def handle(self, record, name=None):
        result = False
        for conn, lev in self.subscriptions.items():
            if record.levelno >= lev:
                msg = record.getMessage()
                if self.modobj.DISPATCHER.send_log_msg(
                        conn, name or self.modobj.name, LEVEL_NAMES[record.levelno], msg):
                    result = True
        if result:
            return True
        for master in self.used_by:
            # this is an iodev, try to handle by one of our masters
            if master.remoteLogHandler.handle(record, self.modobj.name):
                return True
        return False

    def set_conn_level(self, conn, level):
        level = checkLevel(level)
        if level == mlzlog.DEBUG:
            iodev = getattr(self.modobj, '_iodev', None)
            if iodev:
                # we want also to see debug messages of iodev
                if iodev.remoteLogHandler is None:
                    iodev.remoteLogHandler = RemoteLogHandler(self)
                iodev.remoteLogHandler.used_by.add(self.modobj)
        level = checkLevel(level)
        if level == OFF:
            self.subscriptions.pop(conn, None)
        else:
            self.subscriptions[conn] = level