# RD-12 — Move the brief's action lifecycle into the machine

Status: done
Source: PLAN.md 1b#2a

## Why

`brief.store.ts` keeps the action lifecycle in a store-level signal, set imperatively from
about ten places entirely outside the reducer:

```ts
private actionState = signal<ActionState>({ tag: 'Idle' });
readonly busy = computed(() => this.actionState().tag === 'Busy');
readonly lastError = computed(() => { … });
```

So the machine cannot enforce which action transitions are legal, and `ActionState` has two
producers and **zero** consumers that keep the union — both stores immediately collapse it
back to a boolean plus a nullable string, the exact shape its own doc comment says it exists
to remove.

Move it into the machine's `Loaded` state and the reducer owns it, like every other state
change in this house.

## Read first

- `libs/shared/src/application/action-state.ts` — 9 lines, both types. **Only `ActionState`
  is in scope**; `SaveState` is RD-14's.
- `apps/ssp/src/app/brief/application/brief.store.ts` — `actionState` at 44, `busy` at 45,
  `lastError` at 46, and the setter sites in `flushSave` (207), `resetDemo` (226),
  `previewLetter` (251), `revealBigNummer` (269) and `transition` (280)
- `apps/ssp/src/app/brief/domain/brief.machine.ts` — the `Loaded` variant (PascalCase since
  RD-11) and `reduce`
- `apps/ssp/src/app/brief/ui/brief.page.ts:50-126` — the `<app-async>` wrapper. Decision 2
  depends on it.

## Decisions (pre-made, don't relitigate)

1. **`action` becomes a field on `BriefState.Loaded`**, carrying the same three cases
   (`Idle | Busy | Failed{error}`), driven by three new messages — `ActionStarted`,
   `ActionFinished`, `ActionFailed` — handled in `reduce`. The imperative
   `actionState.set(...)` calls become `dispatch(...)`.

2. **This is safe because every action trigger is template-gated, and that was verified, not
   assumed.** `brief.page.ts:55` opens `<ng-template appAsyncLoaded>`, which renders only when
   `remoteData()` is `Success` — i.e. when the machine is `Loaded`. All three entry points sit
   inside it: the reset button (`:83`), `previewLetter` (`:101`, `:120`) and `revealBigNummer`
   (`:102`). `transition` backs submit/approve/reject/send, reachable only from the same
   surface, and `flushSave` runs from the debounced autosave, which only fires while editing a
   loaded brief.

   **If you add an action trigger outside that slot, this design breaks.** Do not add one.

3. **`busy` and `lastError` stay as `computed`s on the store.** They are the render seam, not
   a second encoding: four components take `busy = input(...)` — `behandel-scherm`,
   `letter-composer`, `org-template-editor`, `rejection-comments` — and two pages read
   `store.busy()`/`store.lastError()` directly. A boolean is right at that boundary; the union
   is right in the machine. **Do not push the union down into the components** — it would churn
   four components and their stories for no gain.

4. **`BriefLoaded` resetting `action` to `Idle` is intended.** A fresh load clears a stale
   action error, which is a small behaviour _improvement_: today a failed action's message can
   outlive a reload. Let the reducer do it, and say so in a comment.

5. **`flushSave` sets both `saveState` and `actionState` today. Keep both.** The autosave
   failure legitimately surfaces in two places — the small save indicator and the action error
   line. Only the `actionState` half becomes a dispatch here; leave `saveState` exactly as it
   is.

6. **Do not touch `org-template.store.ts`, `pendingPublish`, or `SaveState`.** RD-13 folds
   org-template (including `pendingPublish`, the one genuine illegal-state pair), and RD-14
   moves `SaveState` and deletes `action-state.ts`. `action-state.ts` therefore still exists
   after this ticket, exporting only `SaveState` plus an `ActionState` that brief no longer
   imports.

## Files

- `apps/ssp/src/app/brief/domain/brief.machine.ts` (+ `.spec.ts`)
- `apps/ssp/src/app/brief/application/brief.store.ts` (+ `.spec.ts`)

Not `action-state.ts` (RD-14 deletes it). Not `org-template.store.ts` (RD-13). No UI files.

## Steps

1. Add `action` to `BriefState.Loaded` and the three messages to `BriefMsg`; handle them in
   `reduce`, including the `BriefLoaded` reset from decision 4.
2. Add reducer spec cases (see Acceptance).
3. Replace each `actionState.set(...)` in `brief.store.ts` with the matching `dispatch`.
4. Re-point `busy` and `lastError` at the machine's `Loaded.action`, keeping their public
   signatures identical so no UI file changes.
5. Run `npm run gen:behaviour-spec` — new `it()` titles otherwise fail the drift check.
6. Update this ticket's `Status:` to `done` and the README's RD-12 row to `done`.
7. Commit all of it together.

## Acceptance criteria

Dry-run against the tree before handover, with the measured baselines: `brief.store.ts` has
**14** `actionState` occurrences and `brief.machine.ts` has **0** action messages; both must
invert. `saveState` is **5** and must stay 5. The `busy`/`lastError` declarations are **2** and
must stay 2.

```bash
B=apps/ssp/src/app/brief
git grep -c "actionState" -- $B/application/brief.store.ts        # MUST return nothing
git grep -n "ActionState" -- $B                                    # MUST return nothing
git grep -c "ActionStarted\|ActionFinished\|ActionFailed" -- $B/domain/brief.machine.ts  # >= 3
```

The render seam is unchanged, so no UI file was touched:

```bash
git diff --name-only HEAD | grep -c "brief/ui/" || true   # MUST be 0
git grep -c "readonly busy\|readonly lastError" -- $B/application/brief.store.ts   # still 2
```

`SaveState` and org-template are untouched (decision 6):

```bash
git diff --name-only HEAD | grep -cE "action-state|org-template" || true   # MUST be 0
git grep -c "saveState" -- $B/application/brief.store.ts   # unchanged: still 5
```

New reducer cases:

```
- ActionStarted moves a loaded brief to Busy
- ActionFailed carries the error
- ActionFinished returns to Idle
- BriefLoaded resets a stale action error to Idle
- an action message is a no-op when the brief is not loaded
```

```bash
npm run ci   # exits 0
```

## Verification

`npm run ci`. No story, no `.mdx`, no `libs/shared/src/ui/**`, so `--full` is not required.

If you do run the full gate, pass `timeout: 600000` on the Bash call — it takes about 8
minutes and the harness backgrounds anything longer than 120s, which would end your turn with
the work uncommitted.

## Out of scope

- `org-template.store.ts` and `pendingPublish` — RD-13.
- `SaveState`, and deleting `action-state.ts` — RD-14.
- The four `busy = input(...)` components and their stories (decision 3).
- The `NO_SUBORGS`/`NO_TABLES`-should-be-`Empty` finding — optional RD-34.

## Risks

- **Decision 2 is the load-bearing assumption.** It holds today because of one
  `<ng-template appAsyncLoaded>`. Re-read `brief.page.ts:50-126` and confirm before you start;
  if any trigger has moved outside that slot since this ticket was written, stop and say so
  rather than adding a guard that changes behaviour.
- **`revealBigNummer` sets only `Failed`, never `Busy`.** Do not "fix" that asymmetry here —
  it is existing behaviour, and changing it is a separate decision.
- **Keep `busy`/`lastError` signatures byte-identical.** They are read from two page templates;
  a renamed or re-typed member turns a pure refactor into a UI change.
- **`behaviour-spec.mdx` drift** from the new spec titles. Run `gen:behaviour-spec` in the same
  commit.