Refund the right Bloomerang gift, exactly once

**Objective:** Refund the transaction of `{amount}` recorded against `{donor-name}`, after confirming it is the right one, and leave an audit trail of why.

**Step 1: Resolve the donor**

Call `bloomerang-get-constituent` with `full-name.contains` set to `{donor-name}`. If more than one matches, list them and stop until told which. If none matches, say so and stop.

Keep the id as the account-id.

**Step 2: Find the transaction**

Call `bloomerang-get-transaction` with that account-id, `amount.min` and `amount.max` both set to `{amount}`, and a date window wide enough to cover it. Show every match with its id, transaction number, date, method, amount and whether it is already marked refunded.

* if exactly one matches and it is not already refunded, carry its id forward
* if more than one matches, list them and stop until told which
* if the only match is already marked refunded, say so and stop

**Step 3: Check what has already been refunded**

Call `bloomerang-get-refund` with `transaction-id` set to the transaction id. If a refund already exists, show it and stop. Refunding twice takes real money out.

**Step 4: Confirm before writing**

Show exactly what will happen: donor name and account number, transaction id, transaction number, original amount and date, the refund date, the reason from `{refund-reason}`, and whether the payment processor will be asked to move money. State that plainly, because a processor refund is not reversible from here.

Wait for explicit confirmation of both the transaction and whether the processor should run the refund.

**Step 5: Write it**

Call `bloomerang-add-refund` once with the confirmed transaction id, date, note and processor flag. Once only. If it fails, report the error verbatim and stop. Do not retry, because the refund may have been taken even when the call reported an error; step 3 is how a person checks.

**Step 6: Verify and record why**

Call `bloomerang-get-refund` with the transaction id and read the stored refund back. Then call `bloomerang-get-transaction` with the account-id and confirm the original now shows as refunded.

Report the outcome: what was refunded, when, for what reason, and whether the processor was involved.

**Rules and Guidelines:**

* The only tool permitted to write here is `bloomerang-add-refund`, once, after explicit confirmation.
* Do not call `bloomerang-update-transaction`, `bloomerang-update-refund`, `bloomerang-add-transaction`, or any other tool whose name starts with bloomerang-add- or bloomerang-update-. Do not correct a transaction by refunding and re-entering it.
* Never set the processor refund flag on your own initiative. It defaults to off and is turned on only when the user says so in this conversation.
* Do not proceed on a partial match of the amount. The figure must match exactly.

**Validation:**

* If `{refund-reason}` is empty, ask for one. A refund with no stated reason should not be written.
* If no transaction matches the amount, widen the date window once and report what the donor actually gave, rather than refunding the nearest figure.