# SLICE 10 — Separate child-notebook kanban and matrix views

> **State-saving rule:** update this file and `TASKS.md` after every completed
> task and whenever work pauses. Automated checks and manual Joplin acceptance
> must be recorded separately.

## Status

**PLANNED.** Implementation has not started. Begin only after SLICE8 and SLICE9
are complete and accepted.

## Goal

When a kanban or matrix block uses `scope: children`, render a separate complete
view for the root notebook and each descendant notebook that owns eligible
cards. This keeps large notebook trees browsable without nesting subsections
inside one board or matrix.

## Confirmed behavior

- Multi-view rendering applies only to the literal `scope: children` keyword.
- `this-folder`, numeric depths (including very large values), and `scope: all`
  keep their current single aggregated view.
- The root notebook gets its own view for cards it owns directly.
- Every descendant notebook gets its own view for cards it owns directly.
- Cards are not rolled up into ancestor views; each card appears exactly once.
- Empty notebook views are omitted.
- If every notebook is empty, show the existing overall empty board/matrix once.
- Each view heading uses a full notebook path so duplicate titles are clear.
- Views use deterministic depth-first tree order: root first, then descendants;
  siblings sort case-insensitively by title with folder ID as a stable tie-breaker.
- Each generated view contains the normal three kanban columns or four matrix
  quadrants, rather than notebook subsections inside those buckets.
- Each bucket receives independent SLICE8 visible-count state and the configured
  `page-size`.
- SLICE9 normal-note cards group by `parent_id` exactly like to-do cards.
- Overall scan statistics count folders and notes once. Card totals equal the sum
  of all non-empty notebook groups.

## Example

```text
Projects                         <- root view (direct cards only)
├── Home                         <- separate Home view
│   ├── Repairs                  <- separate Repairs view
│   └── Garden                   <- separate Garden view
└── Work                         <- separate Work view
    └── Release                  <- separate Release view
```

If `Home` has no eligible cards, its view is omitted; `Repairs` and `Garden`
still appear if they have cards.

## Architecture and data flow

```text
parse scope
  children -> scopeDepth: Infinity + groupByNotebook: true
  other    -> existing values       + groupByNotebook: false
        |
        v
resolve root notebook + ordered scoped folder metadata
        |
        v
collector scans each folder once
  single mode  -> existing aggregate board/matrix
  grouped mode -> one exact-owner board/matrix per folder
        |
        v
plugin payload: discriminated single or notebook-grouped result
        |
        v
webview
  single  -> current component
  grouped -> repeat complete component per non-empty notebook group
             (each component owns independent SLICE8 state)
```

## Data-contract decision

Use a discriminated view layout instead of returning both aggregate and grouped
copies of every card:

```ts
type KanbanLayout =
  | { kind: "single"; board: KanbanBoard }
  | { kind: "notebooks"; groups: NotebookKanbanGroup[] };

type MatrixLayout =
  | { kind: "single"; board: MatrixBoard }
  | { kind: "notebooks"; groups: NotebookMatrixGroup[] };
```

Each group carries `folderId`, `notebookPath`, its board/matrix, `cardCount`, and
item-level warnings for that notebook. Config warnings, notebook-resolution
warnings, and profile-wide soft-cap warnings remain at the overall block level.
The empty grouped case carries `groups: []` and renders one existing empty state.

## Implementation plan

### Phase 1 — Preserve the explicit scope intent

- [ ] Add `groupByNotebook: boolean` to `KanbanConfig` and `MatrixConfig` in
      `src/Gtd/types.ts`.
- [ ] In both parsers, set `scopeDepth = Infinity` and
      `groupByNotebook = true` only for literal `scope: children`.
- [ ] Default `groupByNotebook` to false.
- [ ] Keep `this-folder`, numeric depth, invalid-value fallback, and `scope: all`
      parsing unchanged.
- [ ] When `scope: all` is selected, force or leave `groupByNotebook` false;
      `scopeAll` remains the controlling flag.
- [ ] Add parser tests proving `children` is distinguishable from numeric depth
      and that every other scope form remains single-view.

A boolean is deliberately preferred over a broad scope-enum refactor: existing
collectors still need `scopeDepth` and `scopeAll`, while this slice needs only one
additional rendering decision.

### Phase 2 — Ordered notebook metadata helper

- [ ] Extend `folderScope.ts` or add a focused `folderTree.ts` helper that returns
      scoped folder metadata rather than only IDs when grouping is requested.
- [ ] Include `id`, `parentId`, display title, and full path for the resolved root
      and every descendant.
- [ ] Build paths from the actual notebook tree, including ancestors above a
      `notebook:`-selected root so headings remain unambiguous.
- [ ] Order root first, then perform depth-first traversal with siblings sorted
      by case-insensitive title and folder ID tie-breaker.
- [ ] Handle missing/empty titles with a stable documented fallback such as
      `Untitled notebook` while retaining the folder ID tie-breaker.
- [ ] Defend against malformed folder data (orphan parent references and cycles)
      without hanging; keep every reachable scoped folder at most once.
- [ ] Leave `resolveScopedFolderIds` behavior intact for calendars, Gantt, and
      non-grouped views.

### Phase 3 — Grouped collector contracts

- [ ] Add shared notebook-view metadata types plus `KanbanLayout` and
      `MatrixLayout` discriminated unions in `src/Gtd/types.ts` or collector-local
      result types where appropriate.
- [ ] Refactor kanban collection so each eligible card is appended to the board
      associated with the current scanned `folderId` when grouping is enabled.
- [ ] Apply done-window filtering and sort each kanban group's columns using the
      existing logic.
- [ ] Refactor matrix collection equivalently and sort each group's quadrants.
- [ ] Attach malformed-block/item warnings to the owning notebook group.
- [ ] Omit groups whose final `cardCount` is zero, including groups emptied by
      done-window or eligibility filtering.
- [ ] Retain the current aggregate path and result behavior when grouping is off.
- [ ] Compute overall `scannedFolders`, `scannedNotes`, and `cardCount` once,
      without summing repeated scans or duplicating cards.
- [ ] Ensure the host view note is excluded before group counts are finalized.

### Phase 4 — Plugin payloads and warning ownership

- [ ] Update `handleGetKanban` and `handleGetMatrix` in `src/index.ts` to return
      the discriminated layout plus SLICE8 `pageSize`.
- [ ] Keep config warnings, notebook-resolution warnings, config parse errors,
      and `scope: all` soft-cap warnings at the overall block level.
- [ ] Send item-level warnings inside their notebook group in grouped mode.
- [ ] Preserve the current top-level warning array in single mode.
- [ ] Return a structurally valid empty layout when the source note cannot be
      resolved.
- [ ] Keep overall statistics visible once per source block; optionally show a
      compact per-notebook card count in each generated heading, but do not add
      separate scan totals that could imply folders were scanned repeatedly.

### Phase 5 — Webview component reuse

- [ ] Separate the existing kanban wrapper concerns (overall title, errors,
      global warnings, stats) from rendering one kanban board component.
- [ ] Do the same for one matrix component.
- [ ] In single mode, render exactly one component with current markup and visual
      behavior.
- [ ] In grouped mode, iterate groups in payload order and render one full
      component per group beneath a notebook-path heading.
- [ ] Render each group's item warnings adjacent to that group.
- [ ] Reuse the SLICE8 incremental-list helper inside every component; closure
      state must not be shared between groups or buckets.
- [ ] When `groups` is empty, render the existing empty board/matrix once rather
      than showing a blank block.
- [ ] Add only the spacing/heading CSS required to distinguish notebook views;
      preserve column and matrix layout styles.

### Phase 6 — Automated tests

#### Scope/parser tests

- [ ] `children` sets infinite depth plus grouping.
- [ ] Numeric depth remains non-grouped, including a numeric string.
- [ ] `this-folder`, invalid scope, and omitted scope remain non-grouped.
- [ ] `scope: all` remains non-grouped and retains notebook-conflict warnings.

#### Folder-tree tests

- [ ] Root plus multiple children and grandchildren.
- [ ] Deterministic depth-first order regardless of input folder order.
- [ ] Case-insensitive sibling ordering and folder-ID tie-breaker.
- [ ] Duplicate titles represented by unambiguous full paths.
- [ ] A `notebook:`-selected child root with its ancestor path retained.
- [ ] Empty titles, orphan parents, and cycle protection.

#### Kanban collector tests

- [ ] Root-owned and descendant-owned cards appear in separate exact-owner groups.
- [ ] Every card appears once with no ancestor rollup.
- [ ] Empty groups are omitted while non-empty grandchildren remain.
- [ ] Done-window filtering can remove an otherwise non-empty group.
- [ ] Per-group sorting and warnings are correct.
- [ ] SLICE9 note and to-do cards group identically.
- [ ] Aggregate stats and card totals are not double-counted.
- [ ] Non-grouped scope results remain unchanged.

#### Matrix collector tests

- [ ] Repeat exact-owner, omission, sorting, warning, mixed-card, and total-count
      coverage for Skeleton and Eisenhower modes.
- [ ] Confirm all four quadrants remain local to their owning notebook group.
- [ ] Confirm non-grouped scope results remain unchanged.

#### Payload/rendering contracts

- [ ] Test single and grouped payload construction at the thinnest practical
      boundary without adding a new browser-test dependency solely for this slice.
- [ ] If SLICE8 introduced reusable DOM tests, extend them to prove independent
      visible counts across notebook components; otherwise cover this manually.
- [ ] Run focused parser, folder-tree, kanban, and matrix tests.
- [ ] Run the complete Jest suite and record suite/test totals.
- [ ] Run `npm run dist` and record the produced `.jpl` path.
- [ ] Run `git diff --check` and the prohibited-reference audit.

### Phase 7 — Documentation

- [ ] Update README.md to state that literal `scope: children` produces separate
      notebook views for kanban and matrix blocks.
- [ ] Add a parent/child/grandchild example showing root ownership, omitted empty
      notebooks, full-path headings, and no rollups.
- [ ] State that numeric depth and `scope: all` remain aggregated.
- [ ] Explain that every generated bucket has independent SLICE8 expansion state.
- [ ] Explain that SLICE9 notes group by their owning notebook.
- [ ] Update SPEC.md scope parsing, folder traversal, layout payloads, warning
      ownership, statistics, and rendering flow.
- [ ] Add an unreleased SLICE10 entry to CHANGELOG.md without changing the
      package version until release scope is decided.

### Phase 8 — Manual Joplin acceptance

Create a root notebook containing direct cards, multiple children, grandchildren,
duplicate child titles under different parents, empty notebooks, and more than
one SLICE8 batch in at least two generated views. Include SLICE9 notes and to-dos.

- [ ] Confirm root-owned cards render only in the root view.
- [ ] Confirm every descendant card renders only in its owning notebook view.
- [ ] Confirm empty notebooks are omitted but non-empty descendants still appear.
- [ ] Confirm full paths distinguish duplicate titles.
- [ ] Confirm view ordering is stable and matches the documented traversal.
- [ ] Confirm both matrix modes create separate complete matrices.
- [ ] Confirm per-group warnings appear with the correct notebook.
- [ ] Confirm overall statistics equal the unique scanned/card totals.
- [ ] Confirm independent `page-size` limits and "List more" state across groups,
      buckets, and multiple source blocks.
- [ ] Confirm reload resets all expanded buckets.
- [ ] Confirm `this-folder`, numeric depths, and `scope: all` still render one
      aggregated view.
- [ ] Confirm notebook targeting plus `scope: children` roots grouping at the
      resolved target and uses correct full paths.
- [ ] Confirm sorting, styling, navigation, completion, recurrence, and note-card
      behavior do not regress.
- [ ] Record user sign-off here; do not mark manual acceptance complete before
      confirmation.

## Acceptance criteria

SLICE10 is complete only when:

- Literal `scope: children` renders separate root/descendant views with every
  eligible card present exactly once in its owning notebook.
- Empty groups are omitted, headings are unambiguous, and ordering is stable.
- SLICE8 state is independent per bucket and SLICE9 cards group correctly.
- Warnings and statistics are correctly owned and never double-counted.
- Every other scope form retains its prior single-view behavior.
- Focused tests, the full suite, and the production package build pass.
- Manual Joplin acceptance is explicitly confirmed.

## Files expected to change

- `src/Gtd/types.ts`
- `src/Gtd/parseKanbanConfig.ts`
- `src/Gtd/parseMatrixConfig.ts`
- `src/Gtd/folderScope.ts` and/or a new `src/Gtd/folderTree.ts`
- `src/Gtd/collectKanban.ts`
- `src/Gtd/collectMatrix.ts`
- `src/index.ts`
- `src/gtd-calendar-webview.js`
- `src/event-calendar.css`
- `src/tests/Gtd/kanban.test.ts`
- `src/tests/Gtd/matrix.test.ts`
- `src/tests/Gtd/resolveNotebook.test.ts` and/or a new folder-tree test file
- `README.md`
- `SPEC.md`
- `CHANGELOG.md`
- `SLICE10.md`
- `TASKS.md`

## Out of scope

- Grouping numeric-depth or `scope: all` results.
- Ancestor rollups or duplicated cards across parent/child views.
- Nested notebook subsections inside a single kanban or matrix.
- Persisting expanded/collapsed notebook-view state.
- Notebook-level filtering controls or user-selectable grouping modes.
- Applying notebook grouping to calendar or Gantt views.

## Dependencies and resume point

Implement after SLICE8 and SLICE9 are complete. Start by preserving
`groupByNotebook` in parser tests, then build and test ordered folder metadata.
Introduce discriminated collector layouts before changing the webview. Complete
single-view regression tests before grouped manual acceptance.