"""登录用户去掉 Cookie 明细字段；登录网站增加关联登录用户

1. admin_cookie_user：删除 cookie_value、domain 两列
   登录用户只登记「账号归属」（用户名/昵称/网站/有效期），
   Cookie 明细由「登录网站」承载，故这两列不再需要。

2. admin_cookie_site：新增 cookie_user_id（关联 admin_cookie_user.id）
   用于把网站挂到某个登录用户下，列表/新增/编辑用下拉框选择。

SQLite 不支持直接 DROP COLUMN，统一用 batch_alter_table 重建表；
每一步都先判断列是否存在，便于重复执行与跨环境差异。

Revision ID: e5f6a7b8c9d0
Revises: d4e5f6a7b8c9
"""
from alembic import op
import sqlalchemy as sa

# revision identifiers, used by Alembic.
revision = 'e5f6a7b8c9d0'
down_revision = 'd4e5f6a7b8c9'
branch_labels = None
depends_on = None


def _columns(conn, table):
    insp = sa.inspect(conn)
    return {c['name'] for c in insp.get_columns(table)}


def upgrade():
    conn = op.get_bind()

    user_cols = _columns(conn, 'admin_cookie_user')
    if 'cookie_value' in user_cols:
        with op.batch_alter_table('admin_cookie_user', schema=None) as batch_op:
            batch_op.drop_column('cookie_value')
    if 'domain' in user_cols:
        with op.batch_alter_table('admin_cookie_user', schema=None) as batch_op:
            batch_op.drop_column('domain')

    site_cols = _columns(conn, 'admin_cookie_site')
    if 'cookie_user_id' not in site_cols:
        with op.batch_alter_table('admin_cookie_site', schema=None) as batch_op:
            batch_op.add_column(
                sa.Column('cookie_user_id', sa.Integer(), nullable=True,
                          comment='关联登录用户ID')
            )


def downgrade():
    conn = op.get_bind()

    site_cols = _columns(conn, 'admin_cookie_site')
    if 'cookie_user_id' in site_cols:
        with op.batch_alter_table('admin_cookie_site', schema=None) as batch_op:
            batch_op.drop_column('cookie_user_id')

    user_cols = _columns(conn, 'admin_cookie_user')
    if 'domain' not in user_cols:
        with op.batch_alter_table('admin_cookie_user', schema=None) as batch_op:
            batch_op.add_column(
                sa.Column('domain', sa.String(length=255), nullable=True,
                          server_default='', comment='Cookie域名')
            )
    if 'cookie_value' not in user_cols:
        with op.batch_alter_table('admin_cookie_user', schema=None) as batch_op:
            batch_op.add_column(
                sa.Column('cookie_value', sa.Text(), nullable=True,
                          comment='Cookie值')
            )