from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
from sqlalchemy.orm import DeclarativeBase
from backend.config import get_settings

settings = get_settings()

engine = create_async_engine(settings.database_url, echo=False)
async_session = async_sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)


class Base(DeclarativeBase):
    pass


async def get_db():
    async with async_session() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise


async def init_db():
    async with engine.begin() as conn:
        # 迁移旧表：acme_config → acme_configs
        try:
            result = await conn.execute(
                __import__("sqlalchemy").text("SELECT name FROM sqlite_master WHERE type='table' AND name='acme_config'")
            )
            if result.fetchone():
                await conn.execute(__import__("sqlalchemy").text("ALTER TABLE acme_config RENAME TO acme_configs"))
        except Exception:
            pass

        await conn.run_sync(Base.metadata.create_all)

        # 迁移：给 domains 表加 acme_config_id 列
        try:
            await conn.execute(
                __import__("sqlalchemy").text("ALTER TABLE domains ADD COLUMN acme_config_id INTEGER REFERENCES acme_configs(id)")
            )
        except Exception:
            pass  # 列已存在

        # 确保至少有一条默认配置
        result = await conn.execute(
            __import__("sqlalchemy").text("SELECT COUNT(*) FROM acme_configs")
        )
        count = result.scalar()
        if count == 0:
            await conn.execute(
                __import__("sqlalchemy").text(
                    "INSERT INTO acme_configs (name, acme_server, email, dns_provider, dns_credentials, renew_days) "
                    "VALUES ('默认配置', 'https://acme-v02.api.letsencrypt.org/directory', '', 'aliyun', '{}', 30)"
                )
            )