# Changelog ## v0.9.0 — 2026-09-17 14:24 - **Single-screen 3-pane shell** (PLAN.md "Layout" increment): `app/page.tsx` is now a CSS grid (`grid-template-columns: 300px minmax(0, 1fr) 320px`) — left Assets pane, center = the existing `` **untouched** (its `.map-wrap` fills the middle column, header included), right placeholder `data-testid="right-pane"` with a subtle "Jobs & Market" heading so the next increment has a home - **Single polling source**: new hook `lib/useGameState.ts` polls `GET /api/state` every 1000 ms (configurable arg) and returns `{state, loading, error, refresh}` — overlap guard skips a tick while the previous request is still in flight, interval cleaned up on unmount. Called ONCE in `app/page.tsx`; the snapshot flows down as props so later panes share one poll loop instead of running their own - **Left Assets pane** (`components/LeftPane.tsx`, `data-testid="left-pane"`): wallet cash (formatted EUR), reputation, and a fleet list — per plane: catalog display name (ATR 72-600), status badge, fuel bar + `x / y L`, location (grounded → airport name; flying → "origin → destination" from its bound contract). Time controls: pause/resume toggle + 1x–60x scale select wired to `POST /api/sim`; after each action the pane calls the hook's `refresh()` so it refetches immediately instead of waiting for the next poll tick. Sim clock shown as a UTC wall-clock (`data-testid="sim-clock"`) - Pure display formatters in new `lib/format.ts` — `formatCash` (EUR, 2 dp), `formatFuel` ("x / y L"), `formatSimClock` (epoch ms → deterministic UTC string) - No backend changes: all endpoints pre-existed (`GET /api/state`, `POST /api/sim`); no OpenAPI change; Map.tsx and its header untouched per the increment constraint - Tests: unit — new `lib/format.test.ts` (currency/fuel/clock formatting incl. fractional cash + rounding) and `lib/useGameState.test.ts` (`fetchState` success shape + exact fetch args, non-2xx error with status, network failure via mocked global fetch); e2e — new `e2e/panes.spec.ts`: left pane renders wallet (cash > 0)/reputation/starter ATR 72-600 at Frankfurt + sim clock, time controls pause the sim and set scale 60 through the UI (asserted against authoritative `/api/state` AND in-pane button/select state; restored to scale 1 + unpaused in-test and again in `afterEach`, same pattern as sim.spec.ts), right pane placeholder present - **Known interaction with v0.4.x map e2e**: the three-pane layout narrows the map column to ~660 px at the default 1280×720 viewport, which puts UKBB Boryspil (~475 px east of the [10,52] center at zoom 4) outside the initial view — `e2e/map.spec.ts` marker-click tests re-pointed from UKBB to **LFRS Nantes Atlantique**, now the most isolated large_airport marker inside the new initial viewport (nearest neighbour LFRB ~78 px away), same pattern as the v0.2.7/v0.2.8 dataset re-points - **Pre-existing e2e race fixed** (found while landing this increment, reproduced 5/5 on a clean v0.8.0 worktree deploy — NOT caused by the layout): MapLibre's diff-based `setStyle` removes our custom airports source/layer before `ensureAirportsLayer` re-adds it on the next `styledata` event (~20–40 ms window), and the style-switcher test's post-switch wait (`queryRenderedFeatures > 0`) can be satisfied by stale pre-switch worker data, so its single marker click could land in that gap. The test now retries the click until the popup opens (marker is clickable again within milliseconds; the `toHaveCount(1)` assertion still guards against duplicate listeners) - Verified: unit suite 143 → 150 green; `tsc --noEmit` clean; e2e 18 → 21 green against the rebuilt compose instance (marker-click, zoom clamp and style switch all pass in the narrower middle column) ## v0.8.0 — 2026-09-17 13:54 - **Player-actions API** (PLAN.md "Core loop" increment, server-side only — NO frontend/UI changes): the core loop now works end-to-end through five new endpoints in `lib/game/actions.ts` + `app/api/`. Every action endpoint follows one convention: tick the sim clock FIRST (so validation/mutation see current game time), validate, mutate, persist atomically under the same promise lock as ticks (`engine.runAction()` — no request can interleave between tick and mutation), then return the **FULL state snapshot** (same shape as GET /api/state) with 200 so clients never need a follow-up poll; errors are proper 4xx `{error}` bodies - **Accept**: `POST /api/contracts/:id/accept` — open → accepted only. 404 unknown id, 409 if the contract is not 'open' (accepted/completed/expired). Single-player, so no ownership tracking beyond the status flip; dispatch binds the plane - **Dispatch**: `POST /api/planes/:planeId/dispatch` body `{contractId}` — validates in order: contract exists & status 'accepted' (409 otherwise), plane exists & 'available', `plane.locationIcao === contract.originIcao` (409 "not at origin"), fuel sufficiency `burnPerKm × haversineKm(origin,dest) ≤ plane.fuel` (409 "insufficient fuel"); unknown ids → 404. On success sets the plane 'flying' with `departureSimTime = current clockMs` and lat/lon pinned to the origin — the v0.7.0 finalize path then flies it analytically and pays out on arrival, unchanged - **Market**: `POST /api/market/buy-plane` body `{model}` (400 unknown catalog model; 409 insufficient funds) deducts the full price and delivers a full-tank 'available' plane at home base EDDF; `POST /api/market/sell-plane` body `{planeId}` (409 if flying, 409 for the last remaining plane — the company always keeps ≥1 aircraft) pays out 50% of catalog price and deletes the row. Catalog gains `price: 200_000` on atr72 (with €20k starting cash and ~€1–3k hop rewards, a second ATR takes sustained play — the intended MVP money sink), plus constants `FUEL_PRICE_PER_L = 0.8` €/L and `SELL_FRACTION = 0.5` - **Refuel**: `POST /api/planes/:planeId/refuel` (no body) — grounded planes only (409 if flying); cost `(maxFuel − fuel) × FUEL_PRICE_PER_L`, cash-checked (409), fills to max; a full tank is a free no-op - **Spawn coverage rule** (`engine.spawnCoverageContracts`, in-tick after top-up + finalization): in addition to topping the market up to 10 random open contracts, every airport that currently has a grounded 'available' plane must have ≥1 OPEN contract originating there — one generated per uncovered airport via `generateContract` with origin forced. Guarantees ongoing work wherever the fleet sits (including onboarding at EDDF), and because it runs after finalization a plane that just landed gets work spawned at its new location in the same tick; flying planes don't count - **`generateContract` gains optional `originIcao`/`destIcao`** to force endpoints (used by the coverage rule + test hook); forced endpoints consume no RNG draws, so existing callers are byte-identical (a random origin landing on a forced destination is shifted, mirroring the unforced collision handling) - **Snapshot gains `planes[].departureSimTime`** (null when grounded; sim-clock ms set by dispatch while flying) so clients can compute progress/ETA from the clock — documented in OpenAPI PlaneState - **Test hook generalized**: new `POST /api/test/create-contract` body `{originIcao?, destIcao?, deadlineOffsetMs?}` creates an open contract on a known route (400 unknown ICAO/identical endpoints; default 6–72h window), sibling of `/api/test/expire-contract` under the same `FLIGHT_TEST_HOOKS=1` gate — lets e2e exercise the full loop on a short, deterministic route - **OpenAPI**: all five action endpoints documented with request schemas (DispatchRequest/BuyPlaneRequest/SellPlaneRequest), path parameters, per-endpoint 4xx error shapes and the StateSnapshot success shape; `lib/openapi.test.ts` + `e2e/api.spec.ts` endpoint lists updated four → nine - Tests: unit — new `lib/game/actions.test.ts` (full validation matrix: accept non-open/unknown; dispatch wrong-status ×3, unknown ids, flying plane, not-at-origin, insufficient fuel, success state incl. frozen departure fuel; buy unknown-model/poor/success with home-base delivery; sell flying/last-plane/unknown/success payout+delete; refuel cost math/full-tank no-op/flying/poor/unknown), `lib/sim/engine.test.ts` gains spawn-coverage tests (uncovered grounded airport ⇒ forced-origin contract, already-covered no-op, multi-airport dedupe, flying planes ignored, full tickOnce pipeline) and `lib/game/seed.test.ts` the forced-endpoint matrix; new colocated route tests for all five endpoints (HTTP status codes + snapshot response convention against temp DBs); e2e — new `e2e/actions.spec.ts`: THE full loop on the live origin (self-healing starter plane, hook-created EDDF→closest-airport contract, accept → dispatch with departure set and position moving across polls at scale 60 → arrival paying the EXACT reward + rep gain with analytic remaining fuel → refuel cost deduction → fly home to restore onboarding state) plus the dispatch-without-accept 409 / unknown-id 404 path - Verified: unit suite 86 → 143 green; `tsc --noEmit` clean; e2e 16 → 18 green against the rebuilt compose instance (full loop measured at scale 60); live curl of dispatch + arrival shows the exact cash/rep delta ## v0.7.0 — 2026-09-17 12:27 - **Server-authoritative sim engine** (PLAN.md "Simulation engine" increment 2) in new `lib/sim/` — no frontend/UI changes; dispatch of planes lands next increment, but all the clock/market/finalization machinery it builds on is live and tested now - **Tick-on-read game clock** (`lib/sim/engine.ts`, NO background timer): every read/action endpoint calls `tickNow()` first (GET /api/state, POST /api/sim — and any future action endpoint); the tick advances `clockMs` by `(real ms since last tick) × timeScale`. New `sim_state.last_real_tick_ms` column stores the real-time anchor (seed sets it to the seed moment). **Clamp: `MAX_TICK_ELAPSED_MS = 2000`** — a single tick counts at most 2 s of real absence, chosen above a normal ~1 s poll interval (active play advances ~real time × scale) but small enough that one stale read after an absence moves game time by ≤ 2 s × scale (≤ 2 min at max scale 60), so the sim only meaningfully progresses while actively polled. While paused the clock is frozen but `lastRealTickMs` keeps tracking real time, so unpausing resumes with no catch-up jump. Ticks are serialized through a module-level promise lock (concurrent Next.js requests can't double-advance) and each tick persists via the existing sql.js atomic export - **Analytic movement** (`lib/sim/movement.ts`, pure functions of the sim clock — no incremental stepping): `travelDurationMs(distanceKm, speedKmh)`, `arrivalTimeFor(departureSimTime, distanceKm, speedKmh)`, `progressAt(...)` (clamped 0–1), `positionAt(fromLat, fromLon, toLat, toLon, t)` (great-circle slerp — exact endpoints, stays on the arc), `fuelAt(startFuel, burnPerKm, distanceKm, progress)` (`start − burn·distanceSoFar`, clamped at 0; range exhaustion not modeled yet). New nullable `planes.departure_sim_time` column carries the flight context (route comes from the bound contract, speed/burn from the catalog by model); while flying, `fuel` is frozen at its departure value and GET /api/state reports live lat/lon/fuel computed from the clock - **Arrival finalization** (in-tick): a flying plane whose `arrivalTime ≤ clock` gets its contract marked completed, the exact reward added to `account.cash`, reputation += `1 + 0.0005 × km` (rounded to 2 dp — ~1.15 rep for a 300 km hop, ~2.5 for a 3000 km leg; slow growth from the starting 10), and the plane grounded at the destination with remaining fuel + `departureSimTime = null`. Idempotent by construction: finalization leaves the 'flying' state, so an award can never be paid twice (unit-tested) - **Contract expiry** (in-tick): any `open` contract with `deadlineSimTime ≤ clockMs` → status `'expired'` (new enum value in schema/DDL/snapshot/OpenAPI); accepted/in-flight contracts never expire — they complete. Expired contracts leave the available set the client sees - **Market spawn** (in-tick, after expiry): if open contracts < `MARKET_TARGET_OPEN_CONTRACTS = 10`, new ones are generated to top it up using the SAME builder as the first-run seed — `generateContract({id, airports, rng, nowMs, deadlineOffsetMs?})` extracted from `buildSeed` (same RNG call order, reward formula, cargo flavor, 6–72h game-time deadlines; spawn uses crypto-random UUID ids and the sim clock as "now"). Injectable RNG for deterministic tests - **Time controls endpoint**: new `POST /api/sim` — body `{ timeScale?: number, paused?: boolean }`; unknown fields / non-number timeScale / non-boolean paused → 400; timeScale clamped to [1, 60]; ticks the clock first so the returned simState already reflects current game time. Documented in `lib/openapi.ts` (new SimControlsRequest + Error component schemas; ContractState status enum gains 'expired'; /api/state description notes tick-on-read) - **DB migration for existing installs**: `openGameDb()` now runs a guarded `ALTER TABLE ADD COLUMN` step (PRAGMA table_info check) adding `planes.departure_sim_time` and `sim_state.last_real_tick_ms` to pre-v0.7.0 files, then fixes up the ALTER-default `last_real_tick_ms = 0` to "now" so old DBs resume cleanly instead of taking one clamped catch-up jump - **e2e test hook** (test-only affordance): new `POST /api/test/expire-contract`, enabled ONLY when `FLIGHT_TEST_HOOKS=1` (set in docker-compose.yml for the e2e instance; 404 everywhere else) — with `{contractId}` it moves that open contract's deadline ~10 game-seconds out, without a body it creates a fresh short-deadline open contract; lets the suite observe expiry at scale 60 instead of waiting hours - Tests: unit — new `lib/sim/movement.test.ts` (duration/arrival math, progress boundaries incl. just-before-arrival, slerp endpoints/on-arc/equator-exact/same-point, fuel burn + zero clamp) and `lib/sim/engine.test.ts` (fake-timer clock advance × timeScale, pause freeze + clean resume, 1-hour-gap clamp to exactly one tick, same-ms no-op; expiry flips only open past-deadline contracts incl. the inclusive edge; finalize awards cash+rep exactly once with right remaining fuel and does nothing pre-arrival or without route info; spawn tops up to target via the shared builder — deterministic for an injected RNG); `lib/game/seed.test.ts` gains generateContract coverage (formula, window, determinism, deadlineOffsetMs, buildSeed ≡ builder output) and the simState assertion now includes lastRealTickMs; new `app/api/sim/route.test.ts` (200 shape, clamp to [1,60], pause freeze across ticks, 400 matrix); `lib/db/client.test.ts` gains a legacy-DB migration test; e2e — new `e2e/sim.spec.ts`: scale-60 clock advance bounded per tick by the clamp, exact freeze while paused, expiry of a hook-shortened deadline + market staying ≥ target (both mutate and create hook modes), POST /api/sim validation/clamping - **Known interaction with v0.6.0 e2e**: `e2e/state.spec.ts` restart-persistence test previously asserted the sim clock was byte-identical across a container restart — impossible under tick-on-read by design (every GET advances ≤ one clamped tick). The assertion now checks persistence properly: account/planes/contracts still byte-identical, and post-restart `clockMs ≥ before` bounded by `MAX_TICK_ELAPSED_MS × timeScale`. `e2e/api.spec.ts` endpoint list updated to four - Verified: unit suite 47 → 86 green; `tsc --noEmit` clean; e2e 11 → 16 green against the rebuilt compose instance (incl. restart-persistence); live curl of POST /api/sim + GET /api/state shows the clock advancing at scale 60 then frozen on pause ## v0.6.0 — 2026-09-17 11:49 - Data foundation (PLAN.md "Simulation engine" increment 1): Drizzle ORM + SQLite via **sql.js (WASM)** — chosen over better-sqlite3 because it needs zero native compilation, so the existing oven/bun-alpine install stages and node:22-alpine runtime work unchanged; deps `drizzle-orm@0.45`, `sql.js@1.14` (+ dev-only `@types/sql.js`) - Schema (`lib/db/schema.ts`, DDL mirrored in `lib/db/client.ts`): `planes` (id, model, status available|flying, fuel/maxFuel, locationIcao, contractId?, lat/lon), `contracts` (id, origin/dest ICAO, reward, cargoType/cargoCount, deadlineSimTime, status open|accepted|completed, planeId?, createdSimTime), single-row `account` (cash, reputation) and `sim_state` (clockMs, timeScale 1–60, paused) - First-run seed (`lib/game/seed.ts`) — pure `buildSeed({airports, rng, nowMs})`, fully deterministic with an injected RNG (mulberry32 PRNG exported for tests): starter plane **ATR 72-600** (in-code catalog constant in `lib/game/catalog.ts`: maxFuel 6300 L, burnPerKm 1.75 L/km, speedKmh 510 — structured so more types can be added) grounded full-tank at Frankfurt (**EDDF**; EDDM is Munich), 8–12 open contracts between random distinct CSV airports with reward `round(500 + 2.5 · haversineKm)` (documented simple formula; real revenue/cost modeling is a later increment), cargo flavor (Passengers ≤68 / pallets ≤50), deadline = now + 6–72h game time; account starts at cash 20 000 / reputation 10; simState clockMs = real now, timeScale 1, paused false - Persistence: DB file `db/flight.db` on the host (gitignored) volume-mounted in docker-compose as `./db:/app/db` — a dedicated dir, NOT over `/app/data` (which would mask airports_eu.csv); sql.js keeps the DB in memory, so `persist()` exports the bytes and writes them atomically (tmp file + rename) after every mutation; seeding happens lazily on first access when the account table is empty; `FLIGHT_DB_PATH` env override lets tests point at temp files - New read-only `GET /api/state` (`app/api/state/route.ts`): full snapshot `{account, simState, planes[], contracts[]}` for client polling — plane/contract shapes include airport names (locationName / originName / destName) resolved from the CSV; no tick loop yet, state is static after seed - OpenAPI: `/api/state` documented with component schemas StateSnapshot/AccountState/SimState/PlaneState/ContractState (`lib/openapi.ts`) - `next.config.ts`: `serverExternalPackages: ['sql.js']` — the WASM blob resolves relative to sql.js's dist dir, so it must not be bundled into a .next chunk; known drizzle-orm 0.45.x quirk worked around in code (commented): the sql-js driver drops the result mapper for relational `db.query.*` queries and returns raw snake_case rows, so all reads use plain `select()` - Tests: unit — new `lib/geo.test.ts` (haversine), `lib/game/seed.test.ts` (determinism with fixed RNG, 8–12 count, distinct endpoints, reward formula vs haversine, deadline window, hub + fallback, account/simState values), `lib/db/client.test.ts` (first-run seed + on-disk file, no re-seed on reopen, persist() round-trip) and `app/api/state/route.test.ts` (200 + exact top-level shape against a temp DB); openapi tests updated for the third endpoint; e2e — new `e2e/state.spec.ts`: snapshot shape from the live origin, plus **restart-persistence** test that records cash/clockMs/ids, runs `docker compose restart flight`, waits for readiness and asserts everything unchanged (PLAN.md "sim clock persisted across sessions"); playwright.config gains `workers: 1` so the mid-run container restart can't race the map tests - Verified: unit suite 47/47; `tsc --noEmit` clean; e2e 11/11 green against the rebuilt compose instance (incl. both new state tests); live curl `/api/state` → Frankfurt starter plane + 11 contracts, `/api/airports` still serves 242 features after the mount change; persistence across a full `docker compose up -d --build` verified manually (clockMs/cash/contract count identical before/after) ## v0.5.0 — 2026-09-17 10:15 - New `GET /api/version` (`app/api/version/route.ts`): returns `{ "version": "" }`, version read from package.json via a server-side import (same single-source-of-truth pattern as the header tag) - OpenAPI 3.1 spec in code: `lib/openapi.ts` exports an object documenting exactly the two public endpoints — `GET /api/airports` (GeoJSON FeatureCollection, with component schemas for feature collection/feature/point geometry/properties) and `GET /api/version`; `info.version` is imported from package.json so it stays in sync automatically; `servers: [{ url: "" }]` means "current origin" - New `GET /api/openapi` (`app/api/openapi/route.ts`) serves that spec as JSON — machine-readable API docs for AI agents and external tooling (no interactive docs page, no new dependencies) - AGENTS.md gains a short "## API" section pointing agents at the live base URL and the spec at `https://flight.dev.kkhost.pl/api/openapi`, noting the spec is generated from `lib/openapi.ts` and must be updated whenever endpoints change; this commit also includes the pending local note in AGENTS.md's "## Other" section (use pty_* tools for longer terminal tasks) - Tests: unit — new `app/api/version/route.test.ts` (200 + JSON version equals package.json's, exact body shape) and `lib/openapi.test.ts` (both paths present, info.version in sync with package.json, empty server url, airports schema refs the FeatureCollection/Feature/Properties component schemas with name/icao/lat/lon); e2e — new `e2e/api.spec.ts`: fetches `/api/version` from the live origin and asserts 200 + version matching package.json read at test time; fetches `/api/openapi` and checks content-type, title, info.version and both paths ## v0.4.1 — 2026-09-17 08:50 - Map-asset pack (~100 MB, 780 files) removed from git and from the Docker image: `git rm -r --cached public/{styles,fonts,sprites}` (files kept on disk), `.gitignore` now excludes exactly the generated paths (`public/styles/`, `public/fonts/`, `public/sprites/`, `public/map-assets-manifest.json`) — not all of `public/`; `.dockerignore` gets the same four entries; the v0.4.0 runtime-stage `COPY --from=build /app/public ./public` line is gone from the Dockerfile - The pack now reaches the container via a docker-compose volume mount: `./public:/app/public` on the `flight` service — host dir present with assets → served locally; absent/empty → 404s → runtime fallback (below). Establishes the pattern for the future multi-GB tile file (v0.5.0) that must never go into git - `scripts/download-map-assets.mjs` now writes `public/map-assets-manifest.json` as its LAST step (`{name, generatedAt ISO, styles: [ids]}`) so the manifest's presence proves the whole pack is in place; new npm script `"assets:download": "node scripts/download-map-assets.mjs"` - Runtime fallback for fresh clones without the pack: `lib/mapStyles.ts` gains pure `styleUrlFor(id, localAssetsAvailable)` → `/styles/{id}.json` or `https://tiles.openfreemap.org/styles/{id}`, plus async `localAssetsAvailable()` — fetches `/map-assets-manifest.json` once (module-level cached promise; any non-200/network error → false); the single manifest probe is designed so a future self-hosted tile pack plugs into the same availability mechanism without rework - `components/Map.tsx`: map creation in the mount effect is deferred until the probe resolves (one cheap local request before `new Map`), and the persisted-style restore was folded into that same post-mount flow — localStorage is still read only after mount (SSR-safe), applied at creation time so there's no fiord→saved flash; style switcher changes reuse the cached probe via `styleUrlFor`; all v0.4.0 behavior intact (fiord default, persistence key, idempotent `ensureAirportsLayer` on every `styledata`, single `/api/airports` fetch, `window.__flightMap`) - Tests: unit — new `styleUrlFor` cases (local path / exact remote OFM URL) and `localAssetsAvailable` cases (false on non-200, true + cached with exactly one fetch across awaits via module reset, false on network error); e2e — new test "falls back to remote OFM styles when the local asset pack is absent" routes `/map-assets-manifest.json` → 404, lets `*.openfreemap.org/styles/**` through while aborting all other OFM traffic, and asserts the map initializes from the REMOTE style (glyphs still point at openfreemap.org), the airport count renders, and a UKBB marker click opens its popup — proving fresh-clone-without-assets usability end-to-end - Verified: unit suite 21/21; `tsc --noEmit` clean; e2e suite green against the rebuilt compose instance with assets served from the bind mount (curl: `/styles/fiord.json`, a font `.pbf`, `/sprites/ofm.json` all 200); note the asset blobs remain in git history — no history rewrite was performed ## v0.4.0 — 2026-09-17 08:22 - Self-hosted all OpenFreeMap map-styling assets (tiles stay remote): new `scripts/download-map-assets.mjs` fetches the 5 OFM styles with a browser UA, rewrites each via `rewriteStyle`, and extracts the font/sprite tarballs into `public/` — committed so the image is self-contained: `public/styles/{liberty,bright,positron,dark,fiord}.json` (0.15 MB), `public/fonts/Noto Sans {Regular,Italic,Bold}/*.pbf` (768 files, 99.76 MB — the font payload), `public/sprites/ofm{.json,.png,@2x.json,@2x.png}` (0.21 MB); total public/ = 100.13 MB - New shared module `lib/mapStyles.ts`: `STYLES` registry (5 ids + labels), `DEFAULT_STYLE_ID = 'fiord'`, and pure `rewriteStyle()` — glyphs `https://tiles.openfreemap.org/fonts/{fontstack}/{range}.pbf` → `/fonts/{fontstack}/{range}.pbf`, sprite `https://tiles.openfreemap.org/sprites/ofm_f384/ofm` → `/sprites/ofm`; the vector tile url (`/planet`) and ne2_shaded raster tiles (`/natural_earth/ne2sr/...`) are left remote; every source lacking an attribution gets `"© OpenStreetMap contributors © OpenFreeMap"` (OFM styles ship none; ODbL requires visible OSM credit) - `components/Map.tsx`: map now loads the local `/styles/fiord.json` by default; new top-bar style switcher (`