# =============================================================================
#  license_server/database.py — SQLAlchemy engine + session factory
# =============================================================================

import os
from sqlalchemy import create_engine
from sqlalchemy.orm import DeclarativeBase, sessionmaker

# Default: SQLite in same directory.  Set DATABASE_URL env var for PostgreSQL.
DATABASE_URL = os.getenv(
    "DATABASE_URL",
    "sqlite:///./ar_licenses.db",
)

# connect_args only needed for SQLite (allows multi-threaded use by FastAPI)
_connect_args = {"check_same_thread": False} if DATABASE_URL.startswith("sqlite") else {}

engine = create_engine(DATABASE_URL, connect_args=_connect_args)

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


class Base(DeclarativeBase):
    pass


def get_db():
    """FastAPI dependency that yields a database session."""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()