enhance utilisation of postgres features

server/middleware/cache.go

@@ -1,18 +1,38 @@
 package middleware
 
 import (
-	"vctp/version"
 	"net/http"
+	"strings"
+	"time"
+	"vctp/version"
 )
 
 // CacheMiddleware sets the Cache-Control header based on the version.
 func CacheMiddleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if version.Value == "dev" {
-			w.Header().Set("Cache-Control", "no-cache")
+			w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+			w.Header().Set("Pragma", "no-cache")
+			w.Header().Set("Expires", "0")
 		} else {
-			w.Header().Set("Cache-Control", "public, max-age=31536000")
+			cacheControl := "public, max-age=31536000"
+			if isVersionedAssetRequest(r) {
+				cacheControl += ", immutable"
+			}
+			w.Header().Set("Cache-Control", cacheControl)
+			w.Header().Set("Expires", time.Now().UTC().Add(365*24*time.Hour).Format(http.TimeFormat))
 		}
+		w.Header().Set("Vary", "Accept-Encoding")
 		next.ServeHTTP(w, r)
 	})
 }
+
+func isVersionedAssetRequest(r *http.Request) bool {
+	if r == nil {
+		return false
+	}
+	if r.URL.Query().Get("v") != "" {
+		return true
+	}
+	return strings.Contains(r.URL.Path, "@")
+}