scheduler.py

#
#  engine
#
#  Playout Daemon for autoradio project
#
#
#  Copyright (C) 2017-2018 Gottfried Gaisbauer <gottfried.gaisbauer@servus.at>
#
#  This file is part of engine.
#
#  engine 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 3 of the License, or
#  any later version.
#
#  engine 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 engine. If not, see <http://www.gnu.org/licenses/>.
#

# Meta
__version__ = '0.0.1'
__license__ = "GNU General Public License (GPL) Version 3"
__version_info__ = (0, 0, 1)
__author__ = 'Gottfried Gaisbauer <gottfried.gaisbauer@servus.at>'

"""
Aura Scheduler 
Is holding the eventqueue
"""
import time
import json
import datetime
import decimal
import traceback
import sqlalchemy

import logging
import threading

from operator import attrgetter

from modules.communication.redis.messenger import RedisMessenger
from modules.scheduling.calendar import AuraCalendarService
from libraries.database.broadcasts import Schedule, Playlist, AuraDatabaseModel
from libraries.exceptions.exception_logger import ExceptionLogger
from libraries.enum.auraenumerations import ScheduleEntryType, TimerType


def alchemyencoder(obj):
    """JSON encoder function for SQLAlchemy special classes."""
    if isinstance(obj, datetime.date):
        return obj.isoformat()
    elif isinstance(obj, decimal.Decimal):
        return float(obj)
    elif isinstance(obj, sqlalchemy.orm.state.InstanceState):
        return ""
    elif isinstance(obj, Schedule):
        return json.dumps([obj._asdict()], default=alchemyencoder)
    else:
        return str(obj)


# ------------------------------------------------------------------------------------------ #
class AuraScheduler(ExceptionLogger, threading.Thread):
    """
    Aura Scheduler Class
    Gets data from pv and importer, stores and fires events
    """
    redismessenger = None
    message_timer = []
    job_result = {}

    liquidsoapcommunicator = None
    schedule_entries = None
    active_entry = None
    exit_event = None
    programme = None
    client = None
    logger = None
    config = None

    tried_fetching = 0
    fetch_max = 3

    def __init__(self, config):
        """
        Constructor
        @type    config:               ConfigReader
        @param   config:               read engine.ini
        """
        self.config = config

        # init database ?
        self.init_database()

        self.redismessenger = RedisMessenger(config)
        self.logger = logging.getLogger("AuraEngine")

        # init threading
        threading.Thread.__init__(self)

        # init messenger.. probably not needed anymore
        self.redismessenger.set_channel('scheduler')
        self.redismessenger.set_section('execjob')

        # load error messages
        error_file = self.config.get("install_dir") + "/errormessages/scheduler_error.js"
        f = open(error_file)
        self.error_data = json.load(f)
        f.close()

        #self.redismessenger.send('Scheduler started', '0000', 'success', 'initApp', None, 'appinternal')

        # create exit event
        self.exit_event = threading.Event()

        # start loading new programm every hour
        self.start()

    # ------------------------------------------------------------------------------------------ #
    def init_database(self):
        if self.config.get("recreate_db") is not None:
            AuraDatabaseModel.recreate_db(systemexit=True)

        # check if tables do exist. if not create them
        try:
            Playlist.select_all()
        except sqlalchemy.exc.ProgrammingError as e:
            errcode = e.orig.args[0]

            if errcode == 1146: # error for no such table
                x = AuraDatabaseModel()
                x.recreate_db()
            else:
                raise

    # ------------------------------------------------------------------------------------------ #
    def run(self):
        while not self.exit_event.is_set():
            # set seconds to wait
            seconds_to_wait = int(self.config.get("fetching_frequency"))

            # calc next time
            next_time = datetime.datetime.now() + datetime.timedelta(seconds=seconds_to_wait)

            # write to logger
            self.logger.info("Fetch new programmes every " + str(seconds_to_wait) + "s started. Going to start next time " + str(next_time))

            # empty database
#            self.logger.info("emptying database")
#            ScheduleEntry.truncate()

            # fetch new programme
            self.fetch_new_programme()

            # and wait
            self.exit_event.wait(seconds_to_wait)

    # ------------------------------------------------------------------------------------------ #
    def stop(self):
        self.exit_event.set()

    # ------------------------------------------------------------------------------------------ #
    def get_active_entry(self):
        now_unix = time.mktime(datetime.datetime.now().timetuple())
        lastentry = None

        # load programme if necessary
        if self.programme is None:
            self.logger.debug("want to get active channel, but have to load programme first")
            self.load_programme_from_db()

        # get active source
        for show in self.programme:
            for entry in show.playlist:
                # check if lastentry is set and if act entry is in the future
                if lastentry is not None and entry.entry_start_unix > now_unix:
                    # return entry if so
                    return (show,entry) # actsource = entry.source

                lastentry = entry

        return None

    # ------------------------------------------------------------------------------------------ #
    def load_programme_from_db(self, silent=False):
        self.programme = Schedule.select_act_programme()

        planned_entries = []

        for schedule in self.programme:
            # playlist to play
            schedule.playlist = Playlist.select_playlist(schedule.playlist_id)
            # show fallback is played when playlist fails
            schedule.showfallback = Playlist.select_playlist(schedule.show_fallback_id)
            # timeslot fallback is played when show fallback fails
            schedule.timeslotfallback = Playlist.select_playlist(schedule.timeslot_fallback_id)
            # station fallback is played when timeslot fallback fails
            schedule.stationfallback = Playlist.select_playlist(schedule.station_fallback_id)

            for p in schedule.playlist:
                planned_entries.append(p)

        self.enable_entries(planned_entries)

        self.logger.warning(self.print_message_queue())

    # ------------------------------------------------------------------------------------------ #
    def enable_entries(self, playlist):
        # now in unixtime
        now_unix = time.mktime(datetime.datetime.now().timetuple())

        # switch to check if its the first stream in loaded programme
        first_stream_in_programme = True
        # old entry for fading out
        old_entry = None

        for entry in playlist:
            # since we get also programmes from the past, filter these out
            if entry.entry_start_unix > now_unix:
                # when do we have to start?
                diff = entry.entry_start_unix - now_unix

                diff = diff/100 # testing purpose

                # enable the three timer
                self.enable_timer(diff, entry, old_entry)

            # store the old entry for fading out
            old_entry = entry

    def enable_timer(self, diff, entry, old_entry):
        # create the activation threads and run them after <diff> seconds
        self.logger.critical("ENABLING SWITCHTIMER FOR " + str(entry))
        entry.switchtimer = self.add_or_update_timer(diff, self.liquidsoapcommunicator.activate, [entry])
        self.enable_fading(diff, entry, old_entry)

    # ------------------------------------------------------------------------------------------ #
    def enable_fading(self, diff, new_entry, old_entry):
        # fading times
        fade_out_time = float(self.config.get("fade_out_time"))

        # enable fading when entry types are different
        if old_entry is not None:
            if old_entry.type != new_entry.type:
                #self.add_or_update_timer(diff, self.liquidsoapcommunicator.fade_out, [old_entry])
                old_entry.fadeouttimer = self.create_timer(diff-fade_out_time, self.liquidsoapcommunicator.fade_out, [old_entry], fadeout=True)
                self.logger.critical("ENABLING FADEOUTTIMER FOR " + str(old_entry))

        # same for fadein except old_entry can be None
        if old_entry.type != new_entry.type:
            #self.add_or_update_timer(diff, self.liquidsoapcommunicator.fade_in, [new_entry])
            new_entry.fadeintimer = self.create_timer(diff, self.liquidsoapcommunicator.fade_in, [new_entry], fadein=True)
            self.logger.critical("ENABLING FADEINTIMER FOR " + str(new_entry))

    # ------------------------------------------------------------------------------------------ #
    def add_or_update_timer(self, diff, func, parameters):
        timer = None
        entry = parameters[0]
        planned_timer = self.is_something_planned_at_time(entry.entry_start)

        # if something is planned on entry.entry_start
        if planned_timer:
            planned_entry = planned_timer.entry

            # check if the playlist_id's are different
            if planned_entry.playlist_id != entry.playlist_id:
                # if not stop the old timer and remove it from the list
                self.stop_timer(planned_timer)

                # and create a new one
                timer = self.create_timer(diff, func, parameters, switcher=True)

            # if the playlist id's do not differ => reuse the old timer and do nothing, they are the same

        # if nothing is planned at given time, create a new timer
        else:
            timer = self.create_timer(diff, func, parameters, switcher=True)

        if timer is None:
            return planned_timer
        return timer

    # ------------------------------------------------------------------------------------------ #
    def stop_timer(self, timer):
        # stop timer
        timer.cancel()
        if timer.entry.fadeintimer is not None:
            timer.entry.fadeintimer.cancel()
            self.message_timer.remove(timer.entry.fadeintimer)
        if timer.entry.fadeouttimer is not None:
            timer.entry.fadeouttimer.cancel()
            self.message_timer.remove(timer.entry.fadeouttimer)
        # and remove it from message queue
        self.message_timer.remove(timer)


        self.logger.critical("REMOVED TIMER for " + str(timer.entry))

    # ------------------------------------------------------------------------------------------ #
    def create_timer(self, diff, func, parameters, fadein=False, fadeout=False, switcher=False):
        if not fadein and not fadeout and not switcher or fadein and fadeout or fadein and switcher or fadeout and switcher:
            raise Exception("You have to call me with either fadein=true, fadeout=true or switcher=True")

        t = CallFunctionTimer(diff, func, parameters, fadein, fadeout, switcher)
        self.message_timer.append(t)
        t.start()
        return t

    # ------------------------------------------------------------------------------------------ #
    def is_something_planned_at_time(self, given_time):
        for t in self.message_timer:
            if t.entry.entry_start == given_time:
                return t
        return False

    # ------------------------------------------------------------------------------------------ #
    def get_act_programme_as_string(self):
        programme_as_string = ""

        if self.programme is None or len(self.programme) == 0:
            self.fetch_new_programme()

        try:
            programme_as_string = json.dumps([p._asdict() for p in self.programme], default=alchemyencoder)
        except Exception as e:
            self.logger.error("Cannot transform programme into JSON String. Reason: " + str(e))
            traceback.print_exc()

        return programme_as_string

    # ------------------------------------------------------------------------------------------ #
    def print_message_queue(self):
        message_queue = ""
        for t in sorted(self.message_timer, key=attrgetter('diff')):
            message_queue += str(t)+"\n"

        return message_queue

    # ------------------------------------------------------------------------------------------ #
    def fetch_new_programme(self):
        self.logger.info("trying to fetch new programme")
        if self.tried_fetching == self.fetch_max:
            msg = "Cannot connect to PV or Tank! No Programme loaded!"
            self.logger.error(msg)
            self.tried_fetching = 0
            return msg

        self.tried_fetching += 1

        acs = AuraCalendarService(self.config)
        queue = acs.get_queue()

        # start fetching thread
        acs.start()

        # wait for the end
        response = queue.get()

        if response is None:
            self.logger.critical("Got an EMPTY response from AuraCalendarService: " + str(response))
        elif type(response) is list:
            self.logger.critical("not loading from db")
            self.programme = response
            # self.load_programme_from_db()

            if self.programme is not None and len(self.programme) > 0:
                self.tried_fetching = 0
            if len(self.programme) == 0 and self.tried_fetching == self.fetch_max:
                self.logger.critical("Programme loaded from database has no entries!")

            # return self.get_act_programme_as_string()
        elif response.startswith("fetching_aborted"):
            self.logger.warning("Fetching was being aborted from AuraCalendarService! Reason: " + response)
        else:
            self.logger.warning("Got an unknown response from AuraCalendarService: " + response)

    # ------------------------------------------------------------------------------------------ #
    def set_next_file_for(self, playlistname):
        self.logger.critical("HAVE TO SET NEXT FILE FOR: " + playlistname)
        self.logger.critical(str(self.get_active_entry()))

        if playlistname == "station":
            file = "/var/audio/fallback/eins.zwo.bombe.flac"
        elif playlistname == "timeslot":
            file = "/var/audio/fallback/ratm.killing.flac"
        elif playlistname == "show":
            file = "/var/audio/fallback/weezer.hash.pipe.flac"
        else:
            file = ""
            self.logger.critical("Should set next fallback file for " + playlistname + ", but this playlist is unknown!")

        self.logger.info("Set next fallback file for " + playlistname + ": " + file)
        self.redismessenger.set_next_file_for(playlistname, file)
        return file

    # ------------------------------------------------------------------------------------------ #
    def get_next_file_for(self, fallbackname):
        self.logger.critical("HAVE TO SET NEXT FILE FOR: " + fallbackname)
        (show, entry) = self.get_active_entry()
        self.logger.critical(str(show) + " " + str(entry))

        if fallbackname == "station":
            file = "/var/audio/fallback/eins.zwo.bombe.flac"
        elif fallbackname == "timeslot":
            file = "/var/audio/fallback/ratm.killing.flac"
        elif fallbackname == "show":
            file = "/var/audio/fallback/weezer.hash.pipe.flac"
        else:
            file = ""
            self.logger.critical("Should set next fallback file for " + fallbackname + ", but this playlist is unknown!")

        #set_next_file_thread = SetNextFile(fallbackname, show)
        #set_next_file_thread.start()

#        self.logger.info("Set next fallback file for " + playlistname + ": " + file)
#        self.redismessenger.set_next_file_for(playlistname, file)
        return file

# ------------------------------------------------------------------------------------------ #
class SetNextFile(threading.Thread):
    fallbackname = None
    show = None

    def __init__(self, fallbackname, show):
        threading.Thread.__init__(self)
        self.fallbackname = fallbackname
        self.show = show

    def run(self):
        if self.fallbackname == "show":
            self.detect_next_file_for(self.show.showfallback)
        elif self.fallbackname == "timeslow":
            self.detect_next_file_for(self.show.timeslotfallback)
        elif self.fallbackname == "station":
            self.detect_next_file_for(self.show.stationfallback)

    def detect_next_file_for(self, playlist):
        return ""
        #if playlist.startswith("pool"):
        #    self.find_next_file_in_pool(playlist)

    #def find_next_file_in_pool(self, pool):
    #    return ""

# ------------------------------------------------------------------------------------------ #
class CallFunctionTimer(threading.Timer):
    logger = None
    param = None
    entry = None
    diff = None
    fadein = False
    fadeout = False
    switcher = False

    def __init__(self, diff, func, param, fadein=False, fadeout=False, switcher=False):
        threading.Timer.__init__(self, diff, func, param)

        if not fadein and not fadeout and not switcher or fadein and fadeout or fadein and switcher or fadeout and switcher:
            raise Exception("You have to create me with either fadein=true, fadeout=true or switcher=True")

        self.diff = diff
        self.func = func
        self.param = param
        self.entry = param[0]
        self.fadein = fadein
        self.fadeout = fadeout
        self.switcher = switcher

        self.logger = logging.getLogger("AuraEngine")
        self.logger.debug(str(self))

    # ------------------------------------------------------------------------------------------ #
    def __str__(self):
        if self.fadein:
            return "CallFunctionTimer starting in " + str(self.diff) + "s fading in source '" + str(self.entry)
        elif self.fadeout:
            return "CallFunctionTimer starting in " + str(self.diff) + "s fading out source '" + str(self.entry)
        elif self.switcher:
            return "CallFunctionTimer starting in " + str(self.diff) + "s switching to source '" + str(self.entry)
        else:
            return "CORRUPTED CallFunctionTimer around! How can that be?"