From 92c9072257c9f6e74ec8bbcd1447d58973cde6d4 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Wed, 16 Jan 2019 11:40:51 +0200
Subject: [PATCH] Add WIP example of database usage in bot

---
 examples/README.md               |  1 +
 examples/database/databasebot.py | 39 ++++++++++++++++++++++++++++++++
 examples/database/maubot.yaml    | 10 ++++++++
 3 files changed, 50 insertions(+)
 create mode 100644 examples/database/databasebot.py
 create mode 100644 examples/database/maubot.yaml

diff --git a/examples/README.md b/examples/README.md
index 1837fec..2efabca 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -4,3 +4,4 @@ All examples are published under the [MIT license](LICENSE).
 * [Hello World](helloworld/) - Very basic event handling bot that responds "Hello, World!" to all messages.
 * [Echo bot](https://github.com/maubot/echo) - Basic command handling bot with !echo and !ping commands
 * [Config example](config/) - Simple example of using a config file
+* [Database example](database/) - Simple example of using a database
diff --git a/examples/database/databasebot.py b/examples/database/databasebot.py
new file mode 100644
index 0000000..8cebab6
--- /dev/null
+++ b/examples/database/databasebot.py
@@ -0,0 +1,39 @@
+from typing import Type
+
+from sqlalchemy import Column, String, Text, Table, MetaData, orm, func
+
+from mautrix.types import EventType
+from maubot import Plugin, MessageEvent
+from maubot.handlers import event, command
+
+
+class DatabaseBot(Plugin):
+    db: orm.Session
+    events: Type[Table]
+
+    async def start(self) -> None:
+        await super().start()
+
+        db_factory = orm.sessionmaker(bind=self.database)
+        self.db = orm.scoped_session(db_factory)
+        table_meta = MetaData(bind=self.db)
+        self.events = Table("event", table_meta,
+                            Column("room_id", String(255), primary_key=True),
+                            Column("event_id", String(255), primary_key=True),
+                            Column("sender", String(255)),
+                            Column("body", Text))
+        # In the future, there will be a proper way to include Alembic upgrades in plugins.
+        table_meta.create_all()
+
+    @event.on(EventType.ROOM_MESSAGE)
+    async def handler(self, event: MessageEvent) -> None:
+        self.db.add(self.events(room_id=event.room_id, event_id=event.event_id,
+                                sender=event.sender, body=event.content.body))
+
+    @command.new("stats")
+    async def find(self, _: MessageEvent) -> None:
+        res = (self.db
+               .query(func.sum(self.events.event_id))
+               .group_by(self.events.room_id, self.events.sender)
+               .all())
+        print(res)
diff --git a/examples/database/maubot.yaml b/examples/database/maubot.yaml
new file mode 100644
index 0000000..00c5673
--- /dev/null
+++ b/examples/database/maubot.yaml
@@ -0,0 +1,10 @@
+maubot: 0.1.0
+id: xyz.maubot.databasebot
+version: 1.0.0
+license: MIT
+modules:
+- databasebot
+main_class: DatabaseBot
+
+# This is required for a database to be available.
+database: true