add sqlalchemy to bot startup, fix PyCharm typehinting for Session context manager, simplify autocommit and autoclose separate context managers into singular with kwargs

bot/bot.py

@@ -1,11 +1,12 @@
 import logging
 from contextlib import contextmanager
 from datetime import datetime
+from typing import ContextManager
 
 import discord
 from discord.ext import commands
 from sqlalchemy.engine import Engine
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import Session, sessionmaker
 
 from bot import constants
 from bot.models import Guild, Period
@@ -22,29 +23,17 @@ class ContestBot(commands.Bot):
         self.Session = sessionmaker(bind=engine)
 
     @contextmanager
-    def autocommit(self):
+    def get_session(self, autocommit=True, autoclose=True, rollback=True) -> ContextManager[Session]:
         """Provides automatic commit and closing of Session with exception rollback."""
         session = self.Session()
         try:
             yield session
-            session.commit()
+            if autocommit: session.commit()
         except Exception:
-            session.rollback()
+            if rollback: session.rollback()
             raise
         finally:
-            session.close()
-
-    @contextmanager
-    def autoclose(self):
-        """Provides automatic closing of Session."""
-        session = self.Session()
-        try:
-            yield session
-        except Exception:
-            session.rollback()
-            raise
-        finally:
-            session.close()
+            if autoclose: session.close()
 
     async def fetch_prefix(self, bot: 'ContestBot', message: discord.Message):
         """Fetches the prefix used by the relevant guild."""
@@ -52,7 +41,7 @@ class ContestBot(commands.Bot):
         base = [f'<@!{user_id}> ', f'<@{user_id}> ']
 
         if message.guild:
-            with self.autocommit() as session:
+            with self.get_session() as session:
                 guild = session.query(Guild).filter_by(id=message.guild.id).first()
                 base.append(guild.prefix)
         return base
@@ -67,7 +56,7 @@ class ContestBot(commands.Bot):
         """Handles adding or reactivating a Guild in the database."""
         logger.info(f'Added to new guild: {guild.name} ({guild.id})')
 
-        with self.autocommit() as session:
+        with self.get_session() as session:
             _guild: Guild = session.query(Guild).filter_by(active=False, id=guild.id).first()
             if _guild is None:
                 session.add(Guild(id=guild.id))
@@ -80,7 +69,7 @@ class ContestBot(commands.Bot):
         """Handles disabling the guild in the database, as well."""
         logger.info(f'Removed from guild: {guild.name} ({guild.id})')
 
-        with self.autocommit() as session:
+        with self.get_session() as session:
             # Get the associated Guild and mark it as disabled.
             _guild = session.query(Guild).filter_by(active=True, id=guild.id).first()
             _guild.active = False