Slow sim to 1× on landing and resume last selected speed (ISS-057, v0.30.0)

lib/sim/engine.ts

@@ -75,8 +75,7 @@ export async function tickOnce(inst: GameDb): Promise<schema.SimStateRow> {
   let landedThisTick = 0;
   if (advanceMs > 0) {
     await expirePackages(inst, clockMs);
-    // ISS-041: remember the landings so the tick can pause when this was the last
-    // plane in flight.
+    // ISS-057: remember the landings so the tick can slow down when a plane is left on ground.
     landedThisTick = await deliverPackages(inst, clockMs);
     await spawnOpenPackages(inst, clockMs);
     // AFTER delivery on purpose: a plane that just landed gets work spawned
@@ -84,18 +83,21 @@ export async function tickOnce(inst: GameDb): Promise<schema.SimStateRow> {
     await spawnCoveragePackages(inst, clockMs);
   }
 
-  const sets: Partial<Pick<schema.SimStateRow, 'clockMs' | 'lastRealTickMs' | 'timeScale' | 'paused'>> = {
+  const sets: Partial<Pick<schema.SimStateRow, 'clockMs' | 'lastRealTickMs' | 'timeScale'>> = {
     clockMs,
     lastRealTickMs: nowMs,
   };
-  // Pause on landing (ISS-041): when ≥1 plane landed this tick and NO plane remains in flight,
-  // pause the sim WITHOUT touching timeScale — speed is preserved for the next dispatch.
-  // Arrival-triggered by design: a grounded fleet at high scale is left alone (there is no
-  // auto-resume except starting a flight; see flyPlane). A paused tick never processes landings
-  // (advanceMs === 0), so the trigger can only fire on an advancing tick.
+  // Slow on landing (ISS-057): when ≥1 plane landed this tick and ANY plane is grounded
+  // ('available') afterwards, drop the sim to MIN_TIME_SCALE — a just-landed plane counts, so
+  // any real landing slows. A chained plane stays 'flying' via deliverPackages' auto-chain
+  // branch, so a pure-chain tick with nothing grounded does NOT slow. Pause is manual-only now;
+  // flyPlane restores lastSelectedTimeScale when the last grounded plane takes off. Arrival-
+  // triggered by design: a grounded fleet at high scale is left alone (no idle-enforcement), and
+  // a paused tick never processes landings (advanceMs === 0), so the trigger only fires on an
+  // advancing tick — a manual speed change while planes sit grounded survives until the next landing.
   if (landedThisTick > 0) {
-    const flying = await inst.db.select().from(schema.planes).where(eq(schema.planes.status, 'flying'));
-    if (flying.length === 0) sets.paused = true;
+    const available = await inst.db.select().from(schema.planes).where(eq(schema.planes.status, 'available'));
+    if (available.length >= 1) sets.timeScale = MIN_TIME_SCALE;
   }
 
   // Persist lastRealTickMs even when nothing advanced — it is the tick anchor.
@@ -132,8 +134,8 @@ export async function expirePackages(inst: GameDb, clockMs: number): Promise<num
 // its remaining fuel (a short tank keeps the queue intact for refuel + re-dispatch).
 // Idempotent — a finalized plane either leaves the 'flying' state or starts a NEW
 // leg whose own arrival is in the future, so it can never be awarded twice.
-// Returns planes landed. NOTE: runs BEFORE tickOnce's pause check on purpose —
-// a chained plane counts as still flying there, so chaining never pauses early.
+// Returns planes landed. NOTE: runs BEFORE tickOnce's slow-down check on purpose —
+// a chained plane is already 'flying' again here, so a pure-chain landing never slows the sim.
 export async function deliverPackages(inst: GameDb, clockMs: number): Promise<number> {
   const [planeRows, packageRows] = await Promise.all([
     inst.db.select().from(schema.planes),
@@ -320,13 +322,20 @@ export function runAction<T>(fn: (inst: GameDb) => Promise<T>): Promise<T> {
 
 // Tick first so the returned state reflects current time, then apply the new
 // controls. timeScale is clamped to [1, 1000]; validation of raw input happens in
-// the route handler (400 on non-number / non-boolean).
+// the route handler (400 on non-number / non-boolean). ISS-057: posting a timeScale
+// ALSO records it as lastSelectedTimeScale — the resume target flyPlane restores when
+// the last grounded plane takes off. A {paused}-only post never touches it, so the
+// last manual intent wins without an extra flag.
 export function applyTimeControls(input: SimControlsInput): Promise<schema.SimStateRow> {
   return withLock(async () => {
     const inst = await getGameDb();
     await tickOnce(inst);
-    const sets: Partial<Pick<schema.SimStateRow, 'timeScale' | 'paused'>> = {};
-    if (input.timeScale !== undefined) sets.timeScale = clampTimeScale(input.timeScale);
+    const sets: Partial<Pick<schema.SimStateRow, 'timeScale' | 'lastSelectedTimeScale' | 'paused'>> = {};
+    if (input.timeScale !== undefined) {
+      const scale = clampTimeScale(input.timeScale);
+      sets.timeScale = scale;
+      sets.lastSelectedTimeScale = scale;
+    }
     if (input.paused !== undefined) sets.paused = input.paused;
     if (Object.keys(sets).length > 0) await inst.db.update(schema.simState).set(sets);
     await persist(inst);