commander, plugins/quote: Isolate database configuration.

Not sure if this works for quotes, since that plugin appears to not register
commands correctly. What is up with that?

Refs hamperbot#7.

hamper/commander.py

@@ -1,4 +1,4 @@
-from collections import deque
+from collections import deque, namedtuple
 import logging
 import re
 import traceback
@@ -40,7 +40,7 @@ def nickname(self):
 
     @property
     def db(self):
-        return self.factory.db
+        return self.factory.loader.db
 
     ##### Twisted events #####
 
@@ -114,7 +114,7 @@ def privmsg(self, raw_user, channel, raw_message):
 
     def connectionLost(self, reason):
         """Called when the connection is lost to the server."""
-        self.factory.db.commit()
+        self.factory.loader.db.session.commit()
         if reactor.running:
             reactor.stop()
 
@@ -192,12 +192,14 @@ def __init__(self, config):
 
         if 'db' in config:
             print('Loading db from config: ' + config['db'])
-            self.db_engine = sqlalchemy.create_engine(config['db'])
+            db_engine = sqlalchemy.create_engine(config['db'])
         else:
             print('Using in-memory db')
-            self.db_engine = sqlalchemy.create_engine('sqlite:///:memory:')
-        DBSession = orm.sessionmaker(self.db_engine)
-        self.db = DBSession()
+            db_engine = sqlalchemy.create_engine('sqlite:///:memory:')
+        DBSession = orm.sessionmaker(db_engine)
+        session = DBSession()
+
+        self.loader.db = DB(db_engine, session)
 
         # Load all plugins mentioned in the configuration. Allow globbing.
         plugins = retrieve_named_plugins(IPlugin, config['plugins'], 'hamper.plugins')
@@ -220,6 +222,12 @@ def registerPlugin(self, plugin):
         self.loader.registerPlugin(plugin)
 
 
+class DB(namedtuple("DB", "engine, session")):
+    """
+    A small data structure that stores database information.
+    """
+
+
 class PluginLoader(object):
     """
     I am a repository for plugins.

hamper/plugins/quote.py

@@ -16,8 +16,8 @@ class Quotes(ChatCommandPlugin):
     name = 'quotes'
     priority = 0
 
-    def setup(self, factory):
-        SQLAlchemyBase.metadata.create_all(factory.db_engine)
+    def setup(self, loader):
+        SQLAlchemyBase.metadata.create_all(loader.db.engine)
 
     class DeliverQuote(Command):
         """Deliver a quote."""
@@ -31,7 +31,7 @@ class DeliverQuote(Command):
 
         def command(self, bot, comm, groups):
             index = random.randrange(0, bot.db.query(Quote).count() + 1)
-            quote = bot.factory.db.query(Quote)[index]
+            quote = bot.factory.loader.db.session.query(Quote)[index]
             # Lame twisted irc doesn't support unicode.
             bot.reply(comm, str(quote.text))
             return True
@@ -43,15 +43,15 @@ class AddQuote(Command):
         def command(self, bot, comm, groups):
             text = groups[0]
             quote = Quote(text, comm['user'])
-            bot.factory.db.add(quote)
+            bot.factory.loader.db.session.add(quote)
             bot.reply(comm, 'Succesfully added quote.')
 
     class CountQuotes(Command):
         """Count how many quotes the bot knows."""
         regex = r'^quotes? --count$'
 
         def command(self, bot, comm, groups):
-            count = bot.db.query(Quote).count()
+            count = bot.factory.loader.db.session.query(Quote).count()
             bot.reply(comm, 'I know {0} quotes.'.format(count))