Skolverket MCP Server

/** * Simple in-memory cache with TTL support * Improves performance by caching API responses */ interface CacheEntry<T> { data: T; timestamp: number; ttl: number; } class SimpleCache { private cache: Map<string, CacheEntry<any>> = new Map(); /** * Get cached value if still valid * @param key Cache key * @returns Cached value or undefined if expired/missing */ get<T>(key: string): T | undefined { const entry = this.cache.get(key); if (!entry) { return undefined; } const now = Date.now(); const age = now - entry.timestamp; // Check if cache entry has expired if (age > entry.ttl) { this.cache.delete(key); return undefined; } return entry.data as T; } /** * Set cache value with TTL * @param key Cache key * @param data Data to cache * @param ttl Time to live in milliseconds */ set<T>(key: string, data: T, ttl: number): void { this.cache.set(key, { data, timestamp: Date.now(), ttl }); } /** * Clear specific cache entry * @param key Cache key to clear */ delete(key: string): void { this.cache.delete(key); } /** * Clear all cache entries */ clear(): void { this.cache.clear(); } /** * Get cache statistics */ getStats(): { size: number; keys: string[] } { return { size: this.cache.size, keys: Array.from(this.cache.keys()) }; } /** * Clean up expired entries */ cleanup(): number { const now = Date.now(); let removed = 0; for (const [key, entry] of this.cache.entries()) { const age = now - entry.timestamp; if (age > entry.ttl) { this.cache.delete(key); removed++; } } return removed; } } // Create singleton cache instance export const cache = new SimpleCache(); // Cache TTL constants (in milliseconds) export const CacheTTL = { // Support data changes rarely - cache for 24 hours SUPPORT_DATA: 24 * 60 * 60 * 1000, // 24h // Statistics updates periodically - cache for 1 hour STATISTICS: 60 * 60 * 1000, // 1h // School units can change - cache for 30 minutes SCHOOL_UNITS: 30 * 60 * 1000, // 30min // Surveys update less frequently - cache for 4 hours SURVEYS: 4 * 60 * 60 * 1000, // 4h // Education events can change - cache for 1 hour EDUCATION_EVENTS: 60 * 60 * 1000, // 1h // Läroplan API data is very stable - cache for 24 hours SYLLABUS: 24 * 60 * 60 * 1000 // 24h }; /** * Generate cache key from function name and parameters */ export function generateCacheKey(prefix: string, params: any): string { // Sort and stringify parameters for consistent keys const sortedParams = Object.keys(params || {}) .sort() .reduce((obj: any, key) => { obj[key] = params[key]; return obj; }, {}); return `${prefix}:${JSON.stringify(sortedParams)}`; } /** * Wrapper function to add caching to async functions */ export async function withCache<T>( cacheKey: string, ttl: number, fn: () => Promise<T> ): Promise<T> { // Try to get from cache first const cached = cache.get<T>(cacheKey); if (cached !== undefined) { return cached; } // Execute function and cache result const result = await fn(); cache.set(cacheKey, result, ttl); return result; } // Auto-cleanup expired entries every 5 minutes setInterval(() => { const removed = cache.cleanup(); if (removed > 0) { console.log(`[Cache] Cleaned up ${removed} expired entries`); } }, 5 * 60 * 1000);