feat: v0.19.0 — ISS-011 auto-slow to 1x when all planes have landed

lib/sim/engine.test.ts

@@ -237,6 +237,80 @@ describe('deliverPackages (v0.12.0 arrival delivery)', () => {
   });
 });
 
+describe('auto-slow to 1× when the last plane lands (ISS-011)', () => {
+  const FROM = 'EDDF';
+  const TO = 'LEMD';
+
+  // Starter flying EDDF→LEMD with departureSimTime set so its arrival is EXACTLY T0 —
+  // any advancing tick past T0 finalizes it. timeScale is the value under test.
+  async function setupLanding(name: string, timeScale: number) {
+    const inst = await freshDb(name);
+    const fc = await loadAirportsGeoJson();
+    const from = fc.features.find((f) => f.properties.icao === FROM)!.properties;
+    const to = fc.features.find((f) => f.properties.icao === TO)!.properties;
+    const km = haversineKm(from.lat, from.lon, to.lat, to.lon);
+    const type = PLANE_TYPES.atr72;
+
+    await inst.db.update(schema.simState).set({ timeScale });
+    await inst.db.update(schema.planes)
+      .set({ status: 'flying', destIcao: TO, departureSimTime: T0 - travelMs(km, type.speedKmh), fuel: type.maxFuel })
+      .where(eq(schema.planes.id, 'plane-starter'));
+
+    return { inst, from, km, type };
+  }
+
+  it('last plane lands → stored timeScale becomes 1', async () => {
+    const { inst } = await setupLanding('autoslow-last.db', 1000);
+    vi.setSystemTime(T0 + 2_000); // one full clamped tick at scale 1000 → clock T0+2e6 ≥ arrival (T0)
+
+    const sim = await tickOnce(inst);
+
+    expect(sim.timeScale).toBe(1); // persisted on the sim_state row…
+    expect((await inst.db.select().from(schema.simState))[0].timeScale).toBe(1); // …and visible to the next snapshot
+    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available'); // landing itself unchanged
+  });
+
+  it('a landing while another plane is still flying → no change', async () => {
+    const { inst, from, type } = await setupLanding('autoslow-other.db', 1000);
+    // A second plane on the same route departing at T0 — arrives far after this tick's clock.
+    await inst.db.insert(schema.planes).values({
+      id: 'p-b', model: 'atr72', status: 'flying', fuel: type.maxFuel, maxFuel: type.maxFuel,
+      locationIcao: FROM, destIcao: TO, lat: from.lat, lon: from.lon, departureSimTime: T0,
+    });
+
+    vi.setSystemTime(T0 + 2_000);
+    const sim = await tickOnce(inst);
+
+    expect(sim.timeScale).toBe(1000); // p-b still in flight — no auto-slow
+    const byId = new Map((await inst.db.select().from(schema.planes)).map((p) => [p.id, p.status]));
+    expect(byId.get('plane-starter')).toBe('available'); // the starter did land…
+    expect(byId.get('p-b')).toBe('flying'); // …but the fleet is not idle
+  });
+
+  it('already at 1× → stays 1', async () => {
+    const { inst } = await setupLanding('autoslow-one.db', 1);
+    vi.setSystemTime(T0 + 2_000); // one tick at scale 1 advances 2e3 game ms — past the T0 arrival
+
+    const sim = await tickOnce(inst);
+
+    expect(sim.timeScale).toBe(1);
+    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available');
+  });
+
+  it('paused sim with all planes landed → no change', async () => {
+    const inst = await freshDb('autoslow-paused.db');
+    // The fleet is fully grounded (the seeded starter) — a paused tick must not touch the
+    // scale even though "no plane in flight" holds: the trigger requires a landing this tick.
+    await inst.db.update(schema.simState).set({ timeScale: 1000, paused: true });
+
+    vi.setSystemTime(T0 + 5_000);
+    const sim = await tickOnce(inst);
+
+    expect(sim.timeScale).toBe(1000); // no landing processed while paused → trigger never fires
+    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available');
+  });
+});
+
 describe('spawnOpenPackages', () => {
   it('tops the market up to MARKET_TARGET_OPEN_PACKAGES using the shared seed builder', async () => {
     const inst = await freshDb('spawn.db');

lib/sim/engine.ts

@@ -71,17 +71,33 @@ export async function tickOnce(inst: GameDb): Promise<schema.SimStateRow> {
   const advanceMs = sim.paused ? 0 : Math.min(elapsed, MAX_TICK_ELAPSED_MS) * sim.timeScale;
   const clockMs = Math.round(sim.clockMs + advanceMs);
 
+  let landedThisTick = 0;
   if (advanceMs > 0) {
     await expirePackages(inst, clockMs);
-    await deliverPackages(inst, clockMs);
+    // ISS-011: remember the landings so the tick can auto-slow to 1× when this was
+    // the last plane in flight.
+    landedThisTick = await deliverPackages(inst, clockMs);
     await spawnOpenPackages(inst, clockMs);
     // AFTER delivery on purpose: a plane that just landed gets work spawned
     // at its new location within the same tick.
     await spawnCoveragePackages(inst, clockMs);
   }
 
+  const sets: Partial<Pick<schema.SimStateRow, 'clockMs' | 'lastRealTickMs' | 'timeScale'>> = {
+    clockMs,
+    lastRealTickMs: nowMs,
+  };
+  // Auto-slow (ISS-011): when ≥1 plane landed this tick and NO plane remains in flight,
+  // drop the stored timeScale to 1× — persisted here so the UI slider reflects it on the
+  // next snapshot. Arrival-triggered by design: a grounded fleet at high scale is left
+  // alone (the player speeds up manually again; there is no auto-restore).
+  if (landedThisTick > 0 && !sim.paused) {
+    const flying = await inst.db.select().from(schema.planes).where(eq(schema.planes.status, 'flying'));
+    if (flying.length === 0) sets.timeScale = MIN_TIME_SCALE;
+  }
+
   // Persist lastRealTickMs even when nothing advanced — it is the tick anchor.
-  await inst.db.update(schema.simState).set({ clockMs, lastRealTickMs: nowMs });
+  await inst.db.update(schema.simState).set(sets);
   await persist(inst);
   const updated = (await inst.db.select().from(schema.simState))[0];
   if (!updated) throw new Error('sim_state row missing after tick');