"""Class that manages the database"""

def __init__(self):

if DBManager.INSTANCE is None:

db_connection = sqlalchemy.create_engine("sqlite:///discordbot/mcservers.db",

connect_args={'check_same_thread': False})

Base.metadata.create_all(db_connection)

session_factory = sessionmaker(db_connection, autoflush=False)

_session = scoped_session(session_factory)

self.session = _session()

self.lock = Lock()

DBManager.INSTANCE = self

INSTANCE = None

def add_mcserver_nocommit(self, mcserver_obj: McServerObj):

"""Add a McServer object to the database"""

with self.lock:

new_mcserver = McServer(address=mcserver_obj.address[0], version=mcserver_obj.version,

statuses=[])

self.session.add(new_mcserver)

return new_mcserver

def add_status_nocommit(self, mcserver_obj: McServerObj):

"""Add a McServer object as a Status object"""

self.lock.acquire()

mcserver_db = self.session.query(McServer).filter(McServer.address==mcserver_obj.address[0]).first()

if mcserver_db == None:

# print("Address couldn't be found in the database: " + mcserver_obj.address[0])

self.lock.release()

mcserver_db = self.add_mcserver_nocommit(mcserver_obj)

self.lock.acquire()

statusplayers = []

for playername in mcserver_obj.players:

temp_player = self.session.query(Player).filter(Player.uuid==playername[1]).first()

if temp_player is None:

temp_player = Player(name=playername[0], uuid=playername[1])

self.session.add(temp_player)

temp_statusplayer = StatusPlayer()

temp_player.statusplayers.append(temp_statusplayer)

self.session.add(temp_statusplayer)

statusplayers.append(temp_statusplayer)

new_status = Status(ping=mcserver_obj.ping, online_players=mcserver_obj.online_players)

for item in statusplayers:

new_status.statusplayers.append(item)

self.session.add(new_status)

mcserver_db.statuses.append(new_status)

self.lock.release()

def commit(self):

"""Commits changes to database"""

with self.lock:

try:

self.session.commit()

except sqlalchemy.exc.IntegrityError:

self.session.rollback()

def get_mcserver(self, address):

"""Return the McServer with the given address"""

with self.lock:

mcserver_db = self.session.query(McServer).filter(McServer.address==address).first()

if mcserver_db is None:

return None

status = mcserver_db.statuses[-1]

players = []

for statusplayer in status.statusplayers:

player = self.session.query(Player).get(statusplayer.player_id)

players.append((player.name, player.uuid))

return McServerObj((address, 25565), status.ping, mcserver_db.version, status.online_players, players)

def get_mcservers(self):

"""Returns all McServer objects in the database"""

with self.lock:

ret_list = [McServerObj((item.address, "25565"), item.ping, item.version,

item.online_players, [(player.name, player.uuid) for player in item.players])

for item in self.session.query(McServer).all()]

return ret_list

def get_number_of_mcservers(self):

"""Returns the number of McServer objects in the database"""