# req-035

Schist must implement the procedure described below as
`is_bucket_balance_up_to_date`.

Source: req-030

Satisfied by: task-001, task-006, task-054

## is_bucket_balance_up_to_date

Inputs:

- A bucket, `bucket`

1. Let `cache_key = bucket.balance_cache_key`.
2. If `cache_key` is not in the format, `<string>:<string>`, then return FALSE.
3. Let `drip_id` be the part of `cache_key` before the `:`.
4. If there is no drip with the ID, `drip_id`, then return FALSE.
5. Let `drip` be the drip with the ID, `drip_id`.
6. If there is a drip, `drip_2`, such that `drip_2.timestamp > drip.timestamp`
   and `drip.bucket_id = bucket.id`, then return FALSE.
7. Let `transaction_id` be the part of `cache_key` after the `:`.
8. If there is no transaction with the ID, `transaction_id`, then return FALSE.
9. Let `transaction` be the transaction with the ID, `transaction_id`.
10. If there is a transaction, `transaction_2`, such that
    `transaction_2.timestamp >= transaction.timestamp` and
    `transaction.bucket_id = bucket.id`, then return FALSE.
11. Return TRUE.