feat: migrate entire codebase to TypeScript

src/utils/rateLimit.ts

@@ -0,0 +1,48 @@
+import logger from './logger';
+
+interface RateLimitRecord {
+  count: number;
+  reset: number;
+}
+
+const rateLimitMap = new Map<string, RateLimitRecord>();
+
+export const checkRateLimit = (key: string): boolean => {
+  const now = Date.now();
+  const windowMs = parseInt(process.env.RATE_LIMIT_WINDOW_MS!, 10) || 60000;
+  const maxRequests = parseInt(process.env.RATE_LIMIT_MAX_REQUESTS!, 10) || 30;
+
+  if (!rateLimitMap.has(key)) {
+    rateLimitMap.set(key, { count: 0, reset: now + windowMs });
+  }
+
+  const record = rateLimitMap.get(key)!;
+
+  if (now > record.reset) {
+    record.count = 0;
+    record.reset = now + windowMs;
+  }
+
+  if (record.count >= maxRequests) {
+    logger.warn('Rate limit exceeded', { key, count: record.count, reset: record.reset });
+    return false;
+  }
+
+  record.count++;
+  return true;
+};
+
+export const cleanupRateLimitCache = (): void => {
+  const now = Date.now();
+  const keysToDelete: string[] = [];
+
+  for (const [key, record] of rateLimitMap.entries()) {
+    if (now > record.reset) {
+      keysToDelete.push(key);
+    }
+  }
+
+  for (const key of keysToDelete) {
+    rateLimitMap.delete(key);
+  }
+};