from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, declarative_base
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
import os
from dotenv import load_dotenv

# 加载环境变量
load_dotenv()

# 数据库连接配置
DATABASE_URL = os.getenv(
    "DATABASE_URL", 
    "mysql+pymysql://wqsd:wqsd@2025@rm-bp13g3ra2f59q49xs.mysql.rds.aliyuncs.com:3306/ai_knowledge?charset=utf8&connect_timeout=30&read_timeout=30&write_timeout=30"
)

# 创建同步引擎和会话
engine = create_engine(
    DATABASE_URL,
    pool_size=10,
    max_overflow=20,
    pool_timeout=30,
    echo=False  # 设为True可查看SQL日志
)

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

# 声明基类
Base = declarative_base()

# 获取数据库会话的依赖函数
def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()