A customer is told what happened, and never what might

[sridharkalaibala]

Stage 5 of the print roadmap - "the customer knows".

The thank-you page asked the shop one question, once, as it opened: is this
paid yet. Everything that happened to the order afterwards - a person
accepting it, a ticket coming out of a kitchen printer, the shop refusing it
at 2am - happened behind the customer's back, and the only way to find out was
to walk to the counter and ask.

No ladder

The stage carries its own warning: "Do not ship a stage nothing can move off.
If Ready is unreachable because nobody presses anything, a frozen tracker is
worse than none."

Three of the four rungs everyone has seen on a delivery app are unreachable
here:

rung	why it cannot light
Ready	nothing in the product sets it. Nobody presses anything.
Cooking	we know a ticket printed. Nothing says a cook started.
Accepted	a shop on automatic never decides anything, so the word describes a decision nobody made.

So there is no ladder. There is a trail: what has already happened, each
with the moment it happened, newest last. A trail cannot freeze, because it
never claims anything about what comes next - a shop whose kitchen printer is
off simply has a shorter trail, not a stuck one.

• Placed, from created_date
• Accepted, only where order_state_by names the person who worked the queue
• In the kitchen, only where a till reported that a printer produced paper
• Refused / Cancelled as endings, drawn after the history rather than
  in place of it: a customer who cancelled two minutes late needs to know the
  kitchen had already started

The one thing named before it happens is a held order's acceptance, because
order-approval.js allows pending to move nowhere else. It carries the shop's
own recent answering speed - median over a fortnight, cached, bounded by an
_id range so it is an index walk rather than an in-memory sort - worded as a
description of the past. No cooking time: nothing here knows when food is
finished, and an invented ETA is the number a customer waits against and then
comes to the counter about.

Keys and times on the wire, words on the page, because /order carries its own
Tamil dictionary keyed by the English sentence and a sentence built on the
server arrives as English nothing can translate.

Two bugs found on the way

The history page was making the claim this stage exists to stop. It called
every accepted order "With the kitchen", including ones whose ticket never
printed. Both customer screens are now drawn from the same trail, so they
cannot disagree.

The thank-you page could not reach the shop at all. It resolved the shop
through knownBranchId() and the order through rememberedOrders(), both of
which live in indexedDB.js - which that page does not load and never has.
Both calls sat behind typeof ... === "function" guards, so nothing threw and
nothing showed: the bill-when-paid button and the pay-by-UPI offer have
silently done nothing there since the day they were written. Loading
indexedDB.js is not the fix; it starts a timer that refetches the whole menu
every ten seconds. The page now answers from the ?order= it arrives with or
the sale id on its own receipt, and from posnic_store, whose two spellings
are pinned together by a test.

Cost

The page polls with backoff and asks nothing while the phone is in a
pocket, resuming the moment somebody looks. It stops for good at a settled
state or a payment, and after half an hour regardless. The shop's answering
speed is read only while an order is actually being waited on, once per page
of history rather than once per row, and cached for five minutes per branch.

Checks

• api: 372 suites, 10,797 tests
• tests/online-ordering-ux.test.js: 136
• npm run check: 7/7

The new history-page test was run against the old code first and fails there,
naming every accepted order "With the kitchen".

Not in this PR

ready_by from #790 is drawn on the history page but not on the thank-you
page, because its helper lives in indexedDB.js too. Now that the fetch works,
that is a small follow-up - worth doing as a shared file rather than a second
copy.

[github-actions]

Merged to develop. Anyone can test this - you do not need write access.

Try it at https://develop.posnic.io, or run it yourself:

git fetch origin develop && git checkout develop
npm install && npm --prefix api install
npm run dev   # then http://localhost:3000

When you have tested it, say what you did and what happened, and set
QA passed or QA failed. If you cannot set labels, just comment -
a maintainer will.

Reporting that something is broken is as useful as fixing it. It is
better found here than by a shopkeeper.