Add missing code

matcher/database.py

@@ -0,0 +1,39 @@
+"""Database functions."""
+
+import flask
+import sqlalchemy
+from sqlalchemy import create_engine, func
+from sqlalchemy.engine import reflection
+from sqlalchemy.orm import scoped_session, sessionmaker
+
+session: sqlalchemy.orm.scoping.scoped_session = scoped_session(sessionmaker())
+
+
+def init_db(db_url: str, echo: bool = False) -> None:
+    """Initialise database."""
+    session.configure(bind=get_engine(db_url, echo=echo))
+
+
+def get_engine(db_url: str, echo: bool = False) -> sqlalchemy.engine.base.Engine:
+    """Create an engine objcet."""
+    return create_engine(db_url, pool_recycle=3600, echo=echo)
+
+
+def get_tables() -> list[str]:
+    """Get a list of table names."""
+    tables: list[str] = reflection.Inspector.from_engine(session.bind).get_table_names()
+    return tables
+
+
+def init_app(app: flask.app.Flask, echo: bool = False) -> None:
+    """Initialise database connection within flask app."""
+    db_url = app.config["DB_URL"]
+    session.configure(bind=get_engine(db_url, echo=echo))
+
+    @app.teardown_appcontext
+    def shutdown_session(exception: Exception | None = None) -> None:
+        session.remove()
+
+
+def now_utc():
+    return func.timezone("utc", func.now())