Frontapp MCP Server

import logger from './logger.js'; /** * Cache entry interface */ interface CacheEntry<T> { /** The cached data */ data: T; /** The timestamp when the data was cached */ timestamp: number; /** The expiration time in milliseconds */ expiresIn: number; } /** * Cache options interface */ export interface CacheOptions { /** The default expiration time in milliseconds */ defaultExpiresIn: number; /** The maximum number of entries in the cache */ maxEntries: number; /** Whether to enable debug logging */ debug: boolean; } /** * Default cache options */ const DEFAULT_CACHE_OPTIONS: CacheOptions = { defaultExpiresIn: 5 * 60 * 1000, // 5 minutes maxEntries: 100, debug: false, }; /** * Cache manager * This utility provides caching functionality for API responses and other data */ export class CacheManager { private cache: Map<string, CacheEntry<any>>; private options: CacheOptions; /** * Create a new cache manager * @param options Cache options */ constructor(options: Partial<CacheOptions> = {}) { this.options = { ...DEFAULT_CACHE_OPTIONS, ...options, }; this.cache = new Map<string, CacheEntry<any>>(); // Start the cleanup interval setInterval(() => this.cleanup(), 60 * 1000); // Run cleanup every minute } /** * Get a value from the cache * @param key The cache key * @returns The cached value, or undefined if not found or expired */ public get<T>(key: string): T | undefined { const entry = this.cache.get(key); // If the entry doesn't exist, return undefined if (!entry) { if (this.options.debug) { logger.debug(`Cache miss: ${key}`); } return undefined; } // If the entry has expired, delete it and return undefined if (this.isExpired(entry)) { this.cache.delete(key); if (this.options.debug) { logger.debug(`Cache expired: ${key}`); } return undefined; } // Return the cached data if (this.options.debug) { logger.debug(`Cache hit: ${key}`); } return entry.data; } /** * Set a value in the cache * @param key The cache key * @param data The data to cache * @param expiresIn The expiration time in milliseconds (optional, defaults to defaultExpiresIn) */ public set<T>(key: string, data: T, expiresIn?: number): void { // If the cache is full, remove the oldest entry if (this.cache.size >= this.options.maxEntries) { this.removeOldest(); } // Set the cache entry this.cache.set(key, { data, timestamp: Date.now(), expiresIn: expiresIn || this.options.defaultExpiresIn, }); if (this.options.debug) { logger.debug(`Cache set: ${key}`, { expiresIn: expiresIn || this.options.defaultExpiresIn, size: this.cache.size, }); } } /** * Delete a value from the cache * @param key The cache key * @returns Whether the key was found and deleted */ public delete(key: string): boolean { const result = this.cache.delete(key); if (this.options.debug && result) { logger.debug(`Cache delete: ${key}`); } return result; } /** * Clear the entire cache */ public clear(): void { this.cache.clear(); if (this.options.debug) { logger.debug('Cache cleared'); } } /** * Get the number of entries in the cache * @returns The number of entries */ public size(): number { return this.cache.size; } /** * Get all cache keys * @returns An array of cache keys */ public keys(): string[] { return Array.from(this.cache.keys()); } /** * Get cache statistics * @returns Cache statistics */ public stats(): { size: number; maxEntries: number; oldestEntry: { key: string; age: number } | null; newestEntry: { key: string; age: number } | null; } { let oldestKey: string | null = null; let oldestTimestamp = Infinity; let newestKey: string | null = null; let newestTimestamp = 0; // Find the oldest and newest entries for (const [key, entry] of this.cache.entries()) { if (entry.timestamp < oldestTimestamp) { oldestKey = key; oldestTimestamp = entry.timestamp; } if (entry.timestamp > newestTimestamp) { newestKey = key; newestTimestamp = entry.timestamp; } } const now = Date.now(); return { size: this.cache.size, maxEntries: this.options.maxEntries, oldestEntry: oldestKey ? { key: oldestKey, age: now - oldestTimestamp } : null, newestEntry: newestKey ? { key: newestKey, age: now - newestTimestamp } : null, }; } /** * Check if a cache entry has expired * @param entry The cache entry * @returns Whether the entry has expired */ private isExpired(entry: CacheEntry<any>): boolean { return Date.now() > entry.timestamp + entry.expiresIn; } /** * Remove the oldest entry from the cache */ private removeOldest(): void { let oldestKey: string | null = null; let oldestTimestamp = Infinity; // Find the oldest entry for (const [key, entry] of this.cache.entries()) { if (entry.timestamp < oldestTimestamp) { oldestKey = key; oldestTimestamp = entry.timestamp; } } // Delete the oldest entry if (oldestKey) { this.cache.delete(oldestKey); if (this.options.debug) { logger.debug(`Cache evicted oldest entry: ${oldestKey}`); } } } /** * Clean up expired entries */ private cleanup(): void { const now = Date.now(); let expiredCount = 0; // Delete expired entries for (const [key, entry] of this.cache.entries()) { if (now > entry.timestamp + entry.expiresIn) { this.cache.delete(key); expiredCount++; } } if (this.options.debug && expiredCount > 0) { logger.debug(`Cache cleanup: removed ${expiredCount} expired entries`); } } /** * Get or set a value in the cache with a callback function * @param key The cache key * @param callback The callback function to get the data if not cached * @param expiresIn The expiration time in milliseconds (optional) * @returns The cached or fetched data */ public async getOrSet<T>( key: string, callback: () => Promise<T>, expiresIn?: number ): Promise<T> { // Try to get the value from the cache const cachedValue = this.get<T>(key); if (cachedValue !== undefined) { return cachedValue; } // If not in cache, call the callback to get the data try { const data = await callback(); // Cache the data this.set(key, data, expiresIn); return data; } catch (error) { // If the callback fails, log the error and rethrow logger.error(`Error fetching data for cache key: ${key}`, { error: error instanceof Error ? error.message : String(error), }); throw error; } } } // Export a singleton instance with default options export const cacheManager = new CacheManager(); // Export default export default cacheManager;