chore: initialize public repository

app/database.py

@@ -0,0 +1,39 @@
+from collections.abc import Generator
+
+from sqlalchemy import create_engine
+from sqlalchemy.engine import Engine
+from sqlalchemy.orm import Session, declarative_base, sessionmaker
+
+
+Base = declarative_base()
+
+_ENGINE: Engine | None = None
+_SessionLocal: sessionmaker[Session] | None = None
+
+
+def init_engine(db_url: str) -> Engine:
+    global _ENGINE, _SessionLocal
+
+    connect_args = {}
+    if db_url.startswith("sqlite"):
+        connect_args["check_same_thread"] = False
+
+    _ENGINE = create_engine(db_url, future=True, connect_args=connect_args)
+    _SessionLocal = sessionmaker(bind=_ENGINE, autoflush=False, autocommit=False, future=True)
+    return _ENGINE
+
+
+def get_engine() -> Engine:
+    if _ENGINE is None:
+        raise RuntimeError("Database engine is not initialized")
+    return _ENGINE
+
+
+def get_db() -> Generator[Session, None, None]:
+    if _SessionLocal is None:
+        raise RuntimeError("SessionLocal is not initialized")
+    db = _SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()