service.py

#
# Aura Engine API (https://gitlab.servus.at/aura/engine-api)
#
# Copyright (C) 2020 - The Aura Engine Team.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


import datetime

from enum import Enum

from models import PlayLog, PlayLogSchema, TrackSchema, ActivityLog, HealthHistory, HealthHistorySchema



class NodeType(Enum):
    """
    Types of API Server deployment models.
    """
    MAIN = "main"
    SYNC = "sync"



class ApiService():
    """
    Service handling for API actions.
    """

    config = None
    logger = None
    node_type = None
    sync_host = None
    main_hosts = None
    active_source = None
    api_playlog = None
    api_healthlog = None


    def __init__(self, config, logger):
        """
        Initialize Service.
        """
        self.config = config
        self.logger = logger

        # Evaluate deployment mode
        node_type = NodeType.MAIN
        host_id = config.get("host_id")
        if host_id == 0:
            node_type = NodeType.SYNC

        # Configured as Sync Node
        if not node_type == NodeType.MAIN:
            self.node_type = NodeType.SYNC
            self.main_hosts = [ config.get("main_host_1"), config.get("main_host_2") ]
            if not self.main_hosts[0] and not self.main_hosts[1]:
                self.logger.warn("Not a single main host defined. Be aware what you are doing.")
                msg = "No sync possible as no host nodes are configured"
            else:
                msg = "Syncing data of hosts '%s'" % (self.main_hosts)

        # Configured as Main Node
        else:
            self.node_type = NodeType.MAIN
            self.sync_host = config.get("sync_host")
            if not self.sync_host:
                msg = "No child node for synchronization defined"
            else:
                msg = "Pushing data to '%s'" % (self.sync_host)

        # Set active source
        source = ActivityLog.get_active_source()
        if source: self.active_source = source.source_number
        if not self.active_source:
            if self.node_type == NodeType.MAIN:
                source_number = self.config.get("host_id")
            else:
                source_number = self.config.get("default_source")
            self.set_active_source(source_number)
        self.logger.info("Active source: %s" % self.active_source)

        # Init Sync API endpoints
        self.api_playlog = self.config.get("sync_api_store_playlog")
        self.api_healthlog = self.config.get("sync_api_store_healthlog")

        self.logger.info("Running in '%s' mode. %s." % (self.node_type, msg))


    def current_track(self):  
        """
        Retrieves the currently playing track.  

        Returns:
            (JSON)
        """
        track = PlayLog.select_current()
        track_schema = TrackSchema()
        return track_schema.dump(track)


    def list_tracks(self, page=None, size=None):  
        """
        Lists track-service entries with pagination.

        Args:
            page (Integer): The number of the page to return
            size (Integer): The numbers of items to return

        Returns:
            (JSON)
        """
        if not size or size > 50 or size < 1: size = 20
        tracklist = PlayLog.paginate(page, size, None, None, False)
        tracklist_schema = TrackSchema(many=True)
        return tracklist_schema.dump(tracklist)


    def list_playlog(self, page=None, size=None, from_time=None, to_time=None, skip_synced=False):  
        """
        Get paginated playlog entries for since the given timestamp.  

        Args:
            page (Integer): The number of items to skip before starting to collect the result set
            size (Integer): The numbers of items to return per page
            from_time (datetime): Optionally, get entries after this timestamp (e.g. "2020-08-29T09:12:33.001Z")
            from_time (datetime): Optionally, get entries before this timestamp (e.g. "2020-08-29T09:12:33.001Z")
            skip_synced (Boolean): Optionally, don't return entries which have been posted directly before (sync node only)

        Returns:
            (JSON)
        """
        tracklist = PlayLog.paginate(page, size, from_time, to_time, skip_synced)
        tracklist_schema = TrackSchema(many=True)
        return tracklist_schema.dump(tracklist)


    def store_playlog(self, data): 
        """
        Stores the passed playlog entry.

        Args:
            data (Object): The data to store in the playlog
        """
        if not data.log_source:
            data.log_source = self.host_id

        # Main Node: Alway log entry, independed of the source
        # Sync Node: Only log entry when it's coming from an active source
        if self.node_type == NodeType.MAIN or \
            (self.node_type == NodeType.SYNC and data.log_source == self.active_source):

            playlog = PlayLog(data)
            playlog.save()
            self.logger.debug("Stored playlog for '%s'" % playlog.track_start)

            # Main Node: Push to Sync Node, if enabled
            if self.node_type == NodeType.MAIN and self.sync_host and self.api_playlog:
                playlog_schema = PlayLogSchema()
                json_playlog = playlog_schema.dump(playlog)

                try:
                    api_url = self.sync_host + self.api_playlog
                    r = requests.post(api_url, json=json_playlog)
                    if r.status_code == 200:
                        self.logger.info("Successfully pushed playlog for '%s' to '%s'" % (playlog.track_start, self.sync_host))
                        playlog.is_synced = True
                        playlog.save()
                    else:
                        self.logger.error("Error while pushing playlog to sync-node: " + r.json())
                except Exception as e:
                    self.logger.error("Error while posting to sync-node API '%s'!" % (api_url), e)
        else:
            self.logger.info("Ditching playlog sent from an inactive source")


    def clock_info(self):
        """
        Retrieves the dataset required to render the studio clock.  
        """
        return "studio clock data"


    def set_active_source(self, source_number):
        """
        Sets the active source (engine1, engine2, other) identified by its source number.

        Args:
            source_number (Integer): Number of the engine
        """
        if source_number > 0:
            if self.active_source != source_number:
                self.active_source = source_number
                activity_log = ActivityLog(source_number)
                activity_log.save()


    def get_active_source(self):
        """
        Retrieves number of the currently active source (engine1, engine2, other)

        Returns:
            (Integer)
        """
        return self.active_source


    def get_source_health(self, source_number):
        """
        Retrieves the most recent health info of the requested source

        Args:
            source_number (Integer): Number of the play-out source


        Returns:
            (JSON)
        """
        health = HealthHistory.get_latest_entry(source_number)
        health_schema = HealthHistorySchema()
        return health_schema.dump(health)


    def log_source_health(self, source_number, data):
        """
        Logs an health entry for the given source

        Args:
            source_number (Integer): Number of the play-out source
            data (Object): The data to store in the health log

        """
        if not data.log_source:
            data.log_source = self.host_id

        # Main Node: Alway log entry, independed of the source
        # Sync Node: Only log entry when it's coming from an active source
        if self.node_type == NodeType.MAIN or \
            (self.node_type == NodeType.SYNC and data.log_source == self.active_source):

            healthlog = HealthHistory(data.log_source, data.is_healthy, data.health_info)
            healthlog.save()
            self.logger.debug("Stored health info for '%s'" % healthlog.log_source)

            # Main Node: Push to Sync Node, if enabled
            if self.node_type == NodeType.MAIN and self.sync_host and self.api_healthlog:

                health_schema = HealthHistorySchema()
                json_healthlog = health_schema.dump(healthlog)

                try:
                    api_url = self.sync_host + api_healthlog + "/" + data.log_source
                    r = requests.post(api_url, json=json_healthlog)
                    if r.status_code == 200:
                        self.logger.info("Successfully pushed healthlog for source '%s' to '%s'" % (healthlog.log_source, self.sync_host))
                        playlog.is_synced = True
                        playlog.save()
                    else:
                        self.logger.error("Error while pushing healthlog to sync-node: " + r.json())
                except Exception as e:
                    self.logger.error("Error while posting to sync-node API '%s'!" % (api_url), e)
        else:
            self.logger.info("Ditching healthlog sent from an inactive source")