from tortoise import BaseDBAsyncClient


async def upgrade(db: BaseDBAsyncClient) -> str:
    return """
        ALTER TABLE "banners" ADD "link" VARCHAR(255);
        ALTER TABLE "banners" ALTER COLUMN "title" SET DEFAULT '';
        ALTER TABLE "banners" ALTER COLUMN "title" SET NOT NULL;
        ALTER TABLE "banners" ALTER COLUMN "description" SET DEFAULT '';
        ALTER TABLE "banners" ALTER COLUMN "description" SET NOT NULL;"""


async def downgrade(db: BaseDBAsyncClient) -> str:
    return """
        ALTER TABLE "banners" DROP COLUMN "link";
        ALTER TABLE "banners" ALTER COLUMN "title" DROP NOT NULL;
        ALTER TABLE "banners" ALTER COLUMN "title" DROP DEFAULT;
        ALTER TABLE "banners" ALTER COLUMN "description" DROP NOT NULL;
        ALTER TABLE "banners" ALTER COLUMN "description" DROP DEFAULT;"""