from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from config.settings import DB_CONFIG
from urllib.parse import quote_plus

DATABASE_URL = (
    f"mysql+pymysql://{DB_CONFIG['user']}:{quote_plus(DB_CONFIG['password'])}"
    f"@{DB_CONFIG['host']}:{DB_CONFIG['port']}/{DB_CONFIG['database']}"
)

engine = create_engine(
    DATABASE_URL,
    pool_size=5,         # 默认 5，可根据并发调整
    max_overflow=20,      # 超过 pool_size 后最大溢出连接数
    pool_timeout=30,      # 等待连接的超时时间
    pool_recycle=1800,    # 防止 MySQL server timeout
    pool_pre_ping=True    # 检查连接是否可用
)

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