#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import datetime as dt
import logging
import sys
import time
from contextlib import suppress

import ts3

from .exceptions import DateException

__all__ = ['GroupAssigner']


class GroupAssigner:
    def __init__(self, host: str, port: (str, int), user: str, password: str, sid: (str, int), gid: (str, int),
                 date: dt.date, delta: dt.timedelta):
        # host config
        self.host = host
        self.port = port
        self.user = user
        self.pw = password

        # server and group id
        self.sid = sid
        self.gid = gid

        # start date and delta
        self.sleepstart = date - dt.timedelta(days=1)
        self.startdate = date
        self.enddate = date + delta

        # init connection handler
        self.conn = None

    def __connect(self):
        """ establish query connection and return connection handler """
        # connect to the telnet interface
        self.conn = ts3.query.TS3Connection(self.host, self.port)

        # login
        self.conn.login(client_login_name=self.user, client_login_password=self.pw)

        # select specified sid
        self.conn.use(sid=self.sid)

        # assign friendly nickname
        self.conn.clientupdate(client_nickname=__name__)

    def __disconnect(self):
        """ gracefully logout and disconnect the connection, this should only be called if the exit is intentional """
        try:
            self.conn.logout()
            self.conn.quit()

        # attribute error if disconnect is called prior to the connection being established
        except AttributeError:
            pass

        # broad exception if something unexpected happens
        except ts3.TS3Error as err:
            # log exception
            logging.error(err)

        # exit
        sys.exit()

    def __checkdate(self):
        """ method to check if the current date is still in the configured date range """
        now = dt.date.today()

        # check if still in the configured range
        if not self.startdate <= now <= self.enddate:
            # if date range is exceeded shutdown gracefully
            logging.info('the current date exceeds the configured date range -- exiting')
            self.__disconnect()

        # else continue
        logging.debug('heartbeat - target date within configured date range')

    def __start_sleepstart(self):
        """ method to check if the process is eligible to sleepstart """
        now = dt.date.today()

        # start date already reached proceed
        if self.startdate <= now:
            logging.debug('start date is already reached -- not eligible to sleepstart continue')

        # if startdate within the next 24h proceed to sleepstart
        elif now >= self.startdate - dt.timedelta(days=1):
            # convert both dates to datetime
            starttime = dt.datetime.combine(self.startdate, dt.time(hour=0, minute=0, second=0))
            now = dt.datetime.now()

            # calculate remaining time delta
            remaindelta = starttime - now
            logging.debug(f'target date will be reached in {remaindelta.seconds} seconds -- sleeping')
            time.sleep(remaindelta.seconds + 1)

        else:
            # if the date is too far back raise DateException
            raise DateException('target date is too far in the future')

    def __notifycliententerview(self, data: dict):
        """
        event thrown if a client connects to the server
        :param data: dictionary containing users info
        """
        # return all non voice clients without reasonid 0
        if data['client_type'] != '0' or data['reasonid'] != '0':
            return

        cldbid = data['client_database_id']
        user_grps = data['client_servergroups'].split(sep=',')

        msg = '{client_nickname}:{client_database_id} connected - member of {client_servergroups}'
        logging.debug(msg.format(**data))

        # only try to add nonmembers to group
        if str(self.gid) not in user_grps:
            logging.debug(f'{data["client_nickname"]} is not member of {self.gid}')

            try:
                # Usage: servergroupaddclient sgid={groupID} cldbid={clientDBID}
                cmd = self.conn.servergroupaddclient(sgid=self.gid, cldbid=cldbid)

                if cmd.error['id'] != '0':
                    logging.error(cmd.data[0].decode("utf-8"))

                # log process
                logging.info('add {client_nickname}:{client_database_id} to {gid}'.format(**data, gid=self.gid))

            # log possible key errors while the teamspeak 5 client is not fully released
            except KeyError as err:
                logging.error([err, data])

    def __handle_event(self, event: str, data: dict):
        """ event handler which separates events to their specific handlers """
        # check if event is still eligible
        self.__checkdate()

        # client enter events
        if event == "notifycliententerview":
            self.__notifycliententerview(data)

    def start(self):
        """ main entry point to start the bot """
        # eol to start process ahead of time
        self.__start_sleepstart()

        # proceed only if target date is inside the date range
        self.__checkdate()

        try:
            # init connection
            self.__connect()

        # break if credentials are invalid
        except ts3.query.TS3QueryError as err:
            # log error and disconnect
            logging.error(err)
            self.__disconnect()

        # start processing
        self.__main()

    def __main(self):
        """ main loop """
        # register for "server" notify event
        self.conn.servernotifyregister(event="server")

        # start listening and processing
        while True:
            self.conn.send_keepalive()

            # suppress TimeoutError exceptions
            with suppress(ts3.query.TS3TimeoutError):
                # wait for events
                event = self.conn.wait_for_event(timeout=60)

                # handover event to eventhandler
                self.__handle_event(event.event, event.parsed[0])