"""
DRP Backend — Database Configuration
SQLite + SQLAlchemy for the prototype.
"""

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, declarative_base

DATABASE_URL = "sqlite:///./drp.db"

engine = create_engine(DATABASE_URL, connect_args={"check_same_thread": False})
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()


def get_db():
    """Dependency for FastAPI routes — yields a DB session."""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def init_db():
    """Create all tables. Called once on startup."""
    from models import Base as _  # noqa: ensure models are imported
    Base.metadata.create_all(bind=engine)