# 宇之然内容创作平台 - 数据库配置

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
import os
from dotenv import load_dotenv

load_dotenv()

# 数据库URL（从环境变量读取）
SQLALCHEMY_DATABASE_URL = os.getenv(
    "DATABASE_URL", 
    "postgresql://user:password@localhost:5432/yuzhiran_db"
)

# 创建数据库引擎
engine = create_engine(
    SQLALCHEMY_DATABASE_URL,
    pool_size=20,
    max_overflow=30,
    pool_pre_ping=True,
    echo=False  # 生产环境设为False
)

# 会话工厂
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# 基础模型类
Base = declarative_base()

def get_db():
    """获取数据库会话"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

def init_db():
    """初始化数据库（创建表）"""
    from app.models import Base
    Base.metadata.create_all(bind=engine)