Club Security 1.0.0

src/memory.ts

@@ -0,0 +1,91 @@
+/**
+ * Who has joined a matching instance before.
+ *
+ * Persisted in a hidden string setting as JSON, because the plugin API offers settings as its
+ * only durable store. Capped so it cannot grow without bound; the oldest entries fall off.
+ */
+
+import type { SettingsStore } from '@vrcnext/plugin-api';
+
+import type { Settings } from './settings.js';
+
+export interface SeenEntry {
+  readonly name: string;
+  readonly joins: number;
+  readonly firstSeen: number;
+  readonly lastSeen: number;
+  readonly lastLocation: string;
+}
+
+const MAX_ENTRIES = 2000;
+
+type SeenMap = Record<string, SeenEntry>;
+
+function parse(raw: string): SeenMap {
+  try {
+    const value: unknown = JSON.parse(raw);
+    if (typeof value !== 'object' || value === null || Array.isArray(value)) return {};
+    const out: SeenMap = {};
+    for (const [key, entry] of Object.entries(value as Record<string, unknown>)) {
+      if (typeof entry !== 'object' || entry === null) continue;
+      const e = entry as Record<string, unknown>;
+      out[key] = {
+        name: typeof e['name'] === 'string' ? e['name'] : '',
+        joins: typeof e['joins'] === 'number' ? e['joins'] : 1,
+        firstSeen: typeof e['firstSeen'] === 'number' ? e['firstSeen'] : 0,
+        lastSeen: typeof e['lastSeen'] === 'number' ? e['lastSeen'] : 0,
+        lastLocation: typeof e['lastLocation'] === 'string' ? e['lastLocation'] : '',
+      };
+    }
+    return out;
+  } catch {
+    return {};
+  }
+}
+
+function trimmed(map: SeenMap): SeenMap {
+  const entries = Object.entries(map);
+  if (entries.length <= MAX_ENTRIES) return map;
+  entries.sort((a, b) => b[1].lastSeen - a[1].lastSeen);
+  return Object.fromEntries(entries.slice(0, MAX_ENTRIES));
+}
+
+export class JoinMemory {
+  readonly #store: SettingsStore<Settings>;
+  #map: SeenMap;
+
+  constructor(store: SettingsStore<Settings>) {
+    this.#store = store;
+    this.#map = parse(store.get('memory'));
+  }
+
+  get size(): number {
+    return Object.keys(this.#map).length;
+  }
+
+  /** The entry as it was before this join, or `undefined` for a first-timer. */
+  previous(key: string): SeenEntry | undefined {
+    return this.#map[key];
+  }
+
+  /** Records a join and persists. Returns the entry as it was before. */
+  async record(key: string, name: string, location: string): Promise<SeenEntry | undefined> {
+    const before = this.#map[key];
+    const now = Date.now();
+    this.#map[key] = {
+      name,
+      joins: (before?.joins ?? 0) + 1,
+      firstSeen: before?.firstSeen ?? now,
+      lastSeen: now,
+      lastLocation: location,
+    };
+    this.#map = trimmed(this.#map);
+    await this.#store.set('memory', JSON.stringify(this.#map));
+    return before;
+  }
+
+  async clear(): Promise<void> {
+    this.#map = {};
+    await this.#store.set('memory', '{}');
+  }
+}