增加转格式

lib/stats.js

@@ -0,0 +1,35 @@
+import fs from "fs";
+import path from "path";
+import { fileURLToPath } from "url";
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const STATS_FILE = path.join(__dirname, "../.stats.json");
+
+let data = null;
+
+function load() {
+  if (data) return data;
+  try {
+    data = JSON.parse(fs.readFileSync(STATS_FILE, "utf8"));
+  } catch {
+    data = {};
+  }
+  return data;
+}
+
+function save() {
+  fs.writeFileSync(STATS_FILE, JSON.stringify(data, null, 2));
+}
+
+export function record(category, key) {
+  load();
+  if (!data[category]) data[category] = {};
+  data[category][key] = (data[category][key] || 0) + 1;
+  save();
+}
+
+export function sortByUsage(category, items, getKey = v => v) {
+  load();
+  const counts = data[category] || {};
+  return [...items].sort((a, b) => (counts[getKey(b)] || 0) - (counts[getKey(a)] || 0));
+}