Function resolveInsertOrderKey

apps/sim/lib/table/rows/ordering.ts:191–222

(
  trx: DbTransaction,
  tableId: string,
  requestedPosition?: number
)

 * Caller holds the row-order lock.
 */
export async function resolveInsertOrderKey(
  trx: DbTransaction,
  tableId: string,
  requestedPosition?: number
): Promise<string> {
  const fractionalOrdering = await isFeatureEnabled('tables-fractional-ordering')
  const orderKeyAtSlot = async (slot: number): Promise<string | null> => {
    if (slot < 0) return null
    if (fractionalOrdering) {
      const [r] = await trx
        .select({ orderKey: userTableRows.orderKey })
        .from(userTableRows)
        .where(eq(userTableRows.tableId, tableId))
        .orderBy(asc(userTableRows.orderKey), asc(userTableRows.id))
        .limit(1)
        .offset(slot)
      return r?.orderKey ?? null
    }
    const [r] = await trx
      .select({ orderKey: userTableRows.orderKey })
      .from(userTableRows)
      .where(and(eq(userTableRows.tableId, tableId), eq(userTableRows.position, slot)))
      .limit(1)
    return r?.orderKey ?? null
  }
  if (requestedPosition === undefined) {
    return keyBetween(await maxOrderKey(trx, tableId), null)
  }
  const lo = await orderKeyAtSlot(requestedPosition - 1)
  const hi = await orderKeyAtSlot(requestedPosition)
  return keyBetween(lo, hi)
}

/**
 * Resolves the `order_key` for an insert expressed by an anchor row id —