reasampler/COMPLETED.md

# COMPLETED.md — ReaSampler landed milestones

Completed milestone entries removed from `PLAN.md`. Each entry preserves its
original Goal, Verify, and checklist points with boxes marked done.

---

## Milestone 0 — Transition scaffold: reaper_mpeview → ReaSampler
**Goal:** Retire the MPE scaffold and stand up the sampler's pure core in its
place, preserving the pure-core / REAPER-shell split.
**Verify:** `cmake -B build -S .` configures clean; `cmake --build build` builds
the renamed extension target and the pure-core test target; `ctest --test-dir
build` is green with the new `bank_model` + `peaks` suites present.

- [x] Delete `src/mpe_model.{h,cpp}` and `src/mpe_view.{h,cpp}`; remove
  `tests/test_mpe_model.cpp`.
- [x] Rename the CMake `project()` and the extension MODULE target from
  `reaper_mpeview` to `reaper_reasampler` (binary `OUTPUT_NAME` likewise);
  update `PREFIX ""` / platform SUFFIX blocks to the new target name.
- [x] Replace the pure `mpe_model` static lib + `mpe_model_tests` executable with
  `bank_model` (pure static lib) + `bank_model_tests`; keep the CTest wiring.
- [x] Repoint `src/main.cpp`: drop the `mpe_view.h` include and all `MpeView_*`
  calls (toggle / IsOpen / OnTimer / Cleanup); stub the extension entry so it
  loads, logs to console, and registers nothing MPE-specific. The
  `command_id` / `gaccel` / `hookcommand` registration *pattern* is preserved for
  reuse (CLAUDE.md §REAPER extension contract) — the MPE action string is removed.
- [x] Choose and record the persistent action-id prefix for the sampler family
  (replaces `CEREBELLUM_MPEVIEW_TOGGLE`); this string is forever-stable once
  shipped (CLAUDE.md §action registration).
- [x] Refresh `README.md` layout/next-step sections to the sampler module set.
  (Landed-work reflection is doc-keeper's; this point exists so the stale MPE
  README does not mislead the first implementer.)

---

## Milestone 1 — bank_model + JSON round-trip (pure)
**Goal:** The `Sample` metadata struct and `BankIndex` (add / remove / query /
tier moves / dedup-by-hash) with JSON serialize/deserialize to `std::string`.
CONTEXT.md §Data model, §Module architecture.
**Verify:** CTest green. Round-trip is lossless (deserialize(serialize(x)) == x)
across all fields; dedup-by-hash and tier filtering asserted; **relative paths
only** invariant enforced at the model boundary (no absolute path accepted/stored).

- [x] Define `Sample` with the full field set (id, display name, relative path,
  source mode, source range in project time + PPQ, track GUID(s), wet/dry,
  channels, SR, length sec + beats, capture tempo, optional key, peak/RMS/LUFS,
  clip flag, tier, content hash, provenance, created ts). CONTEXT.md §Data model.
- [x] `BankIndex`: ordered collection keyed by id; add / remove / query.
- [x] Hash lookup for dedup-by-content-hash.
- [x] Tier model (scratch | archive) + tier-move + tier filtering; scratch marked
  auto-prunable.
- [x] JSON serialize/deserialize to/from `std::string`.
- [x] Tests: full-field round-trip lossless; dedup collapses equal-hash adds;
  tier filter/move correct; relative-path invariant rejects absolute paths;
  empty-index and malformed-JSON edge cases.

---

## Milestone 2 — peaks (pure)
**Goal:** Compute waveform min/max bins from raw PCM, dependency-free (not
REAPER's peak API). CONTEXT.md §Module architecture, §Non-goals.
**Verify:** CTest green. Fed a known signal (full-scale sine, ramp), asserted
min/max envelope per bin matches expected within tolerance; channel count
preserved; bin count honored for arbitrary sample lengths (incl. remainder bin).

- [x] Min/max bin computation from interleaved PCM given a target bin count.
- [x] Multi-channel handling (per-channel envelope; no silent fold).
- [x] Tests: sine envelope ≈ ±amplitude; ramp envelope monotonic; DC/silence →
  zero envelope; short-buffer and non-divisible-length edge cases.

---

## Milestone 3 — Offline capture spike (REAPER shell)
**Goal:** Offline-render the time-selection master mix to a wav in the project
bank folder, add a `Sample`, log it. The render-driving spike. CONTEXT.md
§REAPER API surface (offline render), Build order 3.
**Verify (in DAW):** Render runs via `Main_OnCommand(42230)` ("Render using most
recent settings") — REAPER always shows its offline-render progress window; no
stock/header-documented fully-headless path exists. File lands in the
project-relative bank folder at **32-bit float WAV** at project rate (lossless,
dither-free → enables bit-identical/null-test). A `Sample` is added to the
in-memory `BankIndex`. Non-destructive. Unsaved-project state triggers a
Save-As prompt; capture is refused if the user cancels (no default-location
fallback).
**Bit-identical repeats:** two identical requests produce byte-identical files.
**Exact bounds:** rendered length matches the requested range (no rounding, no
added silence without an explicit tail).

- [x] `ICaptureBackend` interface + `CaptureRequest` (source mode, time range,
  wet/dry, tail, SR/bit-depth/channels, output path). CONTEXT.md §capture.
- [x] `OfflineRenderBackend`: drive `GetSetProjectInfo` render settings +
  `GetSetProjectInfo_String` file/pattern/format; **verify every flag against
  `vendor/reaper-sdk/sdk/reaper_plugin_functions.h`.**
- [x] Resolve the no-dialog render command/flag on the current REAPER build
  (open question) and confirm it runs headless.
- [x] Populate a `Sample` from the finished file; hand to `bank_model`; console-log.
- [x] Verify bit-identical repeats and exact-bounds by hand on a known range.

---

## Milestone 4 — persist (index ↔ project ext state)
**Goal:** Write the `BankIndex` JSON to project ext state, reload on project open;
project-relative path resolution. CONTEXT.md §persist, §Persistence & paths.
**Verify (in DAW):** Index survives Save / Save As / close+reopen; **bank travels
with the .rpp**; **relative paths only** in the persisted index (Save As to a new
folder still resolves the bank).

- [x] `SetProjExtState` / `GetProjExtState` under namespace `"reasampler"`.
- [x] Bank-folder resolution from the current project path
  (`EnumProjects` / `GetProjectPathEx`); store under a project-relative subfolder.
- [x] Reload-on-open; confirm survival across Save / Save As.

**Notes/decisions:**
- Storage: `SetProjExtState` / `GetProjExtState`, namespace `"reasampler"`, keys `bank_index` (serialized JSON) and `project_guid`; relative paths only in the persisted index.
- Project identity: keyed off a **minted GUID** stored in ext state (REAPER exposes no native per-project GUID), not the raw `ReaProject*` — a recycled pointer cannot misread a project switch as a Save-As.
- Save-As: **copy** semantics (Daniel's decision) — the `reasampler_bank/` folder is copied under the new `.rpp`; the old project's bank stays intact. Every ext-state write calls `MarkProjectDirty` so captures/GUID changes flush on the normal save.
- Save-As collision — fixed (DAW-verified): the project-identity classifier now keys off the **`ReaProject*` object identity** (`sameProjectObject` signal), not the stored GUID alone. A different project object (tab-switch or open) is always treated as a Load and never relocates a bank, so two Save-As-forked projects sharing a copied GUID on disk cannot cross-contaminate. A forked sibling that still shares the original GUID is re-GUID'd on detection so identities diverge. The hole is closed without force-saving — non-destructive preserved.

---

## D1 — view_mode_model (pure)
**Goal:** REAPER-free mode registry + membership index + folder-tree-aware
visibility derivation + parking/restore planner + JSON round-trip. The heart of the
phase; mirror of `bank_model`. CONTEXT.md §Design View (Module architecture — pure).
**Verify:** CTest green. N-mode model (not a boolean); Arrange + Design seeded.
Restore-planner round-trip (snapshot → park → restore) returns every driven flag to
its captured value. Parent-derivation correct against a supplied folder tree.
JSON round-trip lossless across modes + membership + show-both + snapshots + active
mode.

- [x] Mode registry: ordered (id, display name, ordinal); Arrange + Design seeded;
  add/query more modes (prove N-mode, not binary).
- [x] Membership index: `GUID → { mode ids }` + per-track show-both flag;
  add / remove / retag / query; untagged = Arrange.
- [x] Folder-tree-aware visibility derivation: given a supplied parent↔child tree +
  active mode, compute the visible set (active leaves, derived-visible parents,
  show-both leaves, master always in).
- [x] Parking/restore planner: emit exact (track, flag, value) op-lists for park and
  restore from active mode + snapshot record.
- [x] JSON round-trip: modes + membership + show-both + snapshots + active mode.
- [x] Tests: N-mode add/query; parent follows tagged leaf (multi-mode parent);
  restore-round-trip returns snapshot values (never hardcoded "on"); show-both leaf
  never parked; unknown/stale GUID tolerated; JSON lossless.

---

## D2 — view shell (apply flags in the DAW)
**Goal:** Read the folder tree and drive REAPER flags per the planner.
CONTEXT.md §Design View (view shell, REAPER API surface).
**Verify (in DAW):** Toggling active mode hides + parks inactive leaves
(`B_SHOWINTCP`/`B_SHOWINMIXER`/`B_MAINSEND`/`I_FXEN` + per-FX offline) and restores
active ones from snapshot. **Master untouched. `B_MUTE`/`I_SOLO` untouched.**
Untagged tracks untouched. Parents follow their tagged descendants.

- [x] Build parent↔child tree from `I_FOLDERDEPTH`; feed to `view_mode_model`.
- [x] Snapshot prior flag values (`GetMediaTrackInfo_Value`) before parking.
- [x] Apply park/restore ops (`SetMediaTrackInfo_Value` for the four flags;
  `TrackFX_GetCount` + per-FX `TrackFX_SetOffline`). Verify flag names/signatures.
- [x] GUID resolution: `GetTrackGUID` / `guidToString` / `stringToGuid` (never index).
- [x] Review gate: no path touches master visibility or `B_MUTE`/`I_SOLO`, or any
  untagged track's owned flags.

---

## D3 — persist slice (view state ↔ project ext state)
**Goal:** Serialize the view section into the `"reasampler"` namespace alongside the
bank; reapply the active mode on project open. CONTEXT.md §Design View (persist).
**Verify (in DAW):** Membership + active mode + snapshots survive Save / Save As /
close+reopen; on open, the active mode's visibility + processing is reapplied.
Saved-while-parked project restores parked tracks from persisted snapshots (not to a
guessed "on").

- [x] Serialize/deserialize the view section under `"reasampler"` (shared blob,
  distinct section from the bank index).
- [x] Reapply active mode on project open (rebuild tree, run the planner).
- [x] Confirm survival across Save / Save As; snapshot durability across
  save-while-parked.

---

## D4 — actions
**Goal:** Bindable action set for the mode workflow. CONTEXT.md §Design View
(actions). **Verify (in DAW):** Each action registered (bindable in Actions list);
toggle + mode-jumps MIDI-bindable; tag/untag acts on the current track selection.

- [x] Toggle active mode (cycle; extensible to cycle-all for >2 modes).
- [x] Activate mode: Arrange / Activate mode: Design (direct jumps).
- [x] Tag selected tracks → Design / → Arrange; Untag selected (= → Arrange).
- [x] Show-both for selected tracks (toggle).
- [x] Register each (`command_id`/`gaccel`/`hookcommand`); toggle + jumps MIDI-bindable.

**Notes/decisions:**
- New `src/actions.{h,cpp}` — the Design View action family registered via the
  `command_id`/`gaccel`/`hookcommand` contract in `main.cpp`; MIDI-bindable.
- New `src/track_guid.{h,cpp}` — shared `MediaTrack*` → canonical GUID-string
  formatter; used by both the view shell and the actions layer (single source of
  truth for membership keys).
- Wiring: actions drive the D2 view shell and D3-persisted model; saved active mode
  is reapplied on project load via a load-signal seam in `persist` (`loadFromProject`
  raises it; `main.cpp`'s timer drains it) — `persist` stays model-only.
- A pure `nextModeId` free function added to `view_mode_model` (the N-mode cycle
  decision behind "toggle"), unit-tested in the existing `view_mode_model_tests`.