feat(api): expose cache config snapshot

Co-Authored-By: Virgil <virgil@lethean.io>

api.go

@@ -37,6 +37,9 @@ type Engine struct {
 	addr                           string
 	groups                         []RouteGroup
 	middlewares                    []gin.HandlerFunc
+	cacheTTL                       time.Duration
+	cacheMaxEntries                int
+	cacheMaxBytes                  int
 	wsHandler                      http.Handler
 	wsPath                         string
 	sseBroker                      *SSEBroker

cache_config.go

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: EUPL-1.2
+
+package api
+
+import "time"
+
+// CacheConfig captures the configured response cache settings for an Engine.
+//
+// It is intentionally small and serialisable so callers can inspect the active
+// cache policy without needing to rebuild middleware state.
+//
+// Example:
+//
+//	cfg := api.CacheConfig{Enabled: true, TTL: 5 * time.Minute}
+type CacheConfig struct {
+	Enabled    bool
+	TTL        time.Duration
+	MaxEntries int
+	MaxBytes   int
+}
+
+// CacheConfig returns the currently configured response cache settings for the engine.
+//
+// The result snapshots the Engine state at call time.
+//
+// Example:
+//
+//	cfg := engine.CacheConfig()
+func (e *Engine) CacheConfig() CacheConfig {
+	if e == nil {
+		return CacheConfig{}
+	}
+
+	cfg := CacheConfig{
+		TTL:        e.cacheTTL,
+		MaxEntries: e.cacheMaxEntries,
+		MaxBytes:   e.cacheMaxBytes,
+	}
+	if e.cacheTTL > 0 {
+		cfg.Enabled = true
+	}
+	return cfg
+}

modernization_test.go

@@ -5,6 +5,7 @@ package api_test
 import (
 	"slices"
 	"testing"
+	"time"
 
 	api "dappco.re/go/core/api"
 )
@@ -94,6 +95,25 @@ func TestEngine_ChannelsIter_Good_SnapshotsCurrentChannels(t *testing.T) {
 	}
 }
 
+func TestEngine_CacheConfig_Good_SnapshotsCurrentSettings(t *testing.T) {
+	e, _ := api.New(api.WithCacheLimits(5*time.Minute, 10, 1024))
+
+	cfg := e.CacheConfig()
+
+	if !cfg.Enabled {
+		t.Fatal("expected cache config to be enabled")
+	}
+	if cfg.TTL != 5*time.Minute {
+		t.Fatalf("expected TTL %v, got %v", 5*time.Minute, cfg.TTL)
+	}
+	if cfg.MaxEntries != 10 {
+		t.Fatalf("expected MaxEntries 10, got %d", cfg.MaxEntries)
+	}
+	if cfg.MaxBytes != 1024 {
+		t.Fatalf("expected MaxBytes 1024, got %d", cfg.MaxBytes)
+	}
+}
+
 func TestEngine_Register_Good_IgnoresNilGroups(t *testing.T) {
 	e, _ := api.New()
 

options.go

@@ -529,6 +529,9 @@ func WithCacheLimits(ttl time.Duration, maxEntries, maxBytes int) Option {
 		if ttl <= 0 {
 			return
 		}
+		e.cacheTTL = ttl
+		e.cacheMaxEntries = maxEntries
+		e.cacheMaxBytes = maxBytes
 		store := newCacheStore(maxEntries, maxBytes)
 		e.middlewares = append(e.middlewares, cacheMiddleware(store, ttl))
 	}