"""数据库连接与初始化"""
from pathlib import Path

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

from config import settings

engine = create_engine(
    f"sqlite:///{settings.database_path}",
    connect_args={"check_same_thread": False},
    echo=False,
)

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


@event.listens_for(engine, "connect")
def _set_sqlite_pragma(dbapi_conn, connection_record):
    """启用 SQLite 外键约束"""
    cursor = dbapi_conn.cursor()
    cursor.execute("PRAGMA foreign_keys=ON")
    cursor.close()


def get_db():
    """FastAPI 依赖注入用数据库会话"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def init_db():
    """创建所有数据表，并确保数据库目录存在"""
    Path(settings.DATABASE_URL).parent.mkdir(parents=True, exist_ok=True)
    Base.metadata.create_all(bind=engine)