feat(sim): clock tick and events

src/sim/clock.ts

@@ -0,0 +1,31 @@
+import { Catalog } from './catalog';
+import { Customer, customersPerHour, spawnCustomer } from './customers';
+import { random } from './rng';
+import { CLOSE_MINUTES, GameState, OPEN_MINUTES } from './state';
+
+export type SimEvent =
+  | { type: 'shop_opened' }
+  | { type: 'customer_arrived'; customer: Customer }
+  | { type: 'shop_closed' };
+
+export function isOpen(state: GameState): boolean {
+  return state.minutes >= OPEN_MINUTES && state.minutes < CLOSE_MINUTES;
+}
+
+/** Advances the clock minute by minute, stopping at closing time. */
+export function tick(state: GameState, catalog: Catalog, deltaMinutes: number): SimEvent[] {
+  const events: SimEvent[] = [];
+  for (let i = 0; i < deltaMinutes && state.minutes < CLOSE_MINUTES; i++) {
+    state.minutes += 1;
+    if (state.minutes === OPEN_MINUTES) events.push({ type: 'shop_opened' });
+    if (state.minutes > OPEN_MINUTES) {
+      state.customerAccumulator += (customersPerHour(state.reputation) / 60) * (0.5 + random(state));
+      while (state.customerAccumulator >= 1) {
+        state.customerAccumulator -= 1;
+        events.push({ type: 'customer_arrived', customer: spawnCustomer(state, catalog) });
+      }
+    }
+    if (state.minutes === CLOSE_MINUTES) events.push({ type: 'shop_closed' });
+  }
+  return events;
+}

tests/sim/clock.test.ts

@@ -0,0 +1,33 @@
+import { describe, it, expect } from 'vitest';
+import { isOpen, tick } from '../../src/sim/clock';
+import { CLOSE_MINUTES, createNewGame, OPEN_MINUTES } from '../../src/sim/state';
+import { testCatalog } from './helpers';
+
+const catalog = testCatalog();
+
+describe('clock', () => {
+  it('opens the shop at 9:00 with no customers before', () => {
+    const s = createNewGame(1);
+    const events = tick(s, catalog, 60);
+    expect(s.minutes).toBe(OPEN_MINUTES);
+    expect(events).toEqual([{ type: 'shop_opened' }]);
+    expect(isOpen(s)).toBe(true);
+  });
+
+  it('brings customers during opening hours and closes at 19:00', () => {
+    const s = createNewGame(1);
+    s.reputation = 100;
+    const events = tick(s, catalog, 24 * 60);
+    expect(s.minutes).toBe(CLOSE_MINUTES);
+    expect(events.filter((e) => e.type === 'customer_arrived').length).toBeGreaterThan(10);
+    expect(events[events.length - 1]).toEqual({ type: 'shop_closed' });
+    expect(isOpen(s)).toBe(false);
+  });
+
+  it('does nothing once closed', () => {
+    const s = createNewGame(1);
+    tick(s, catalog, 24 * 60);
+    expect(tick(s, catalog, 60)).toEqual([]);
+    expect(s.minutes).toBe(CLOSE_MINUTES);
+  });
+});