package helps import (	"sync"	"time") type CodexCache struct {	ID     string	Expire time.Time} // codexCacheMap stores prompt cache IDs keyed by model+user_id.// Protected by codexCacheMu. Entries expire after 1 hour.var (	codexCacheMap = make(map[string]CodexCache)	codexCacheMu  sync.RWMutex) // codexCacheCleanupInterval controls how often expired entries are purged.const codexCacheCleanupInterval = 15 * time.Minute // codexCacheCleanupOnce ensures the background cleanup goroutine starts only once.var codexCacheCleanupOnce sync.Once // startCodexCacheCleanup launches a background goroutine that periodically// removes expired entries from codexCacheMap to prevent memory leaks.func startCodexCacheCleanup() {	go func() {		ticker := time.NewTicker(codexCacheCleanupInterval)		defer ticker.Stop()		for range ticker.C {			purgeExpiredCodexCache()		}	}()} // purgeExpiredCodexCache removes entries that have expired.func purgeExpiredCodexCache() {	now := time.Now()	codexCacheMu.Lock()	defer codexCacheMu.Unlock()	for key, cache := range codexCacheMap {		if cache.Expire.Before(now) {			delete(codexCacheMap, key)		}	}} // GetCodexCache retrieves a cached entry, returning ok=false if not found or expired.func GetCodexCache(key string) (CodexCache, bool) {	codexCacheCleanupOnce.Do(startCodexCacheCleanup)	codexCacheMu.RLock()	cache, ok := codexCacheMap[key]	codexCacheMu.RUnlock()	if !ok || cache.Expire.Before(time.Now()) {		return CodexCache{}, false	}	return cache, true} // SetCodexCache stores a cache entry.func SetCodexCache(key string, cache CodexCache) {	codexCacheCleanupOnce.Do(startCodexCacheCleanup)	codexCacheMu.Lock()	codexCacheMap[key] = cache	codexCacheMu.Unlock()}