Token blacklist, cache and metadata improvements

TokenBlacklist Improvements:
Fixed size limit enforcement to properly maintain max size of 1000 tokens
Improved eviction strategy to remove expired tokens first before removing oldest
Added proper cleanup of tokens during Add operation to prevent size overflow
Fixed oldest token eviction logic to ensure correct token removal
Added proper locking mechanisms to prevent race conditions
Cache Improvements:
Fixed cleanup mechanism to only remove truly expired items
Improved eviction strategy in LRU cache to prioritize expired items
Added smarter eviction in evictOldest to scan for expired items first
Fixed aggressive cleanup that was removing valid items
Maintained proper LRU ordering while handling evictions
MetadataCache:
Verified proper implementation of metadata caching with hourly refresh
Confirmed proper handling of cache extension on fetch failures
Validated thread-safe operations with proper RWMutex usage

helpers.go

@@ -11,7 +11,6 @@ import (
 	"net/http/cookiejar"
 	"net/url"
 	"strings"
-	"sync"
 	"time"
 )
 
@@ -283,79 +282,6 @@ func extractClaims(tokenString string) (map[string]interface{}, error) {
 	return claims, nil
 }
 
-// TokenBlacklist maintains a thread-safe list of revoked tokens.
-// It stores tokens with their expiration times and automatically
-// removes expired entries during cleanup operations.
-type TokenBlacklist struct {
-	// blacklist maps token IDs to their expiration times
-	blacklist map[string]time.Time
-
-	// mutex protects concurrent access to the blacklist
-	mutex sync.RWMutex
-
-	// maxSize is the maximum number of tokens in the blacklist
-	maxSize int
-}
-
-// NewTokenBlacklist creates a new TokenBlacklist instance.
-func NewTokenBlacklist() *TokenBlacklist {
-	return &TokenBlacklist{
-		blacklist: make(map[string]time.Time),
-		maxSize:   1000, // Limit the size to prevent unbounded growth
-	}
-}
-
-// Add adds a token to the blacklist with an expiration time.
-func (tb *TokenBlacklist) Add(tokenID string, expiration time.Time) {
-	tb.mutex.Lock()
-	defer tb.mutex.Unlock()
-
-	// Clean up expired tokens if we're at capacity
-	if len(tb.blacklist) >= tb.maxSize {
-		now := time.Now()
-		for token, exp := range tb.blacklist {
-			if now.After(exp) {
-				delete(tb.blacklist, token)
-			}
-		}
-		// If still at capacity after cleanup, remove oldest token
-		if len(tb.blacklist) >= tb.maxSize {
-			var oldestToken string
-			var oldestTime time.Time
-			first := true
-			for token, exp := range tb.blacklist {
-				if first || exp.Before(oldestTime) {
-					oldestToken = token
-					oldestTime = exp
-					first = false
-				}
-			}
-			delete(tb.blacklist, oldestToken)
-		}
-	}
-	tb.blacklist[tokenID] = expiration
-}
-
-// IsBlacklisted checks if a token is in the blacklist and not expired.
-func (tb *TokenBlacklist) IsBlacklisted(tokenID string) bool {
-	tb.mutex.RLock()
-	defer tb.mutex.RUnlock()
-	expiration, exists := tb.blacklist[tokenID]
-	return exists && time.Now().Before(expiration)
-}
-
-// Cleanup removes expired tokens from the blacklist.
-func (tb *TokenBlacklist) Cleanup() {
-	tb.mutex.Lock()
-	defer tb.mutex.Unlock()
-	now := time.Now()
-	for tokenID, expiration := range tb.blacklist {
-		if now.After(expiration) {
-			delete(tb.blacklist, tokenID)
-		}
-	}
-}
-
 // TokenCache provides a caching mechanism for validated tokens.
 // It stores token claims to avoid repeated validation of the
 // same token, improving performance for frequently used tokens.