Caching and user data endpoint

app/controllers/caching/caching.scala

@@ -0,0 +1,26 @@
+package controllers.caching
+
+import play.api.mvc.Results.NotModified
+import play.api.mvc.{Request, Result}
+
+import scala.concurrent.{ExecutionContext, Future}
+
+trait Etagable[A]:
+  extension (a: A) def etag: String
+
+
+extension [A, R[X] <: Request[X], E: Etagable](request: R[A]) {
+  def checkFreshAsync(entity: E)(onStale: => Future[Result])(using ec: ExecutionContext): Future[Result] = {
+    compareEtag(entity).fold(onStale)(
+      etag => Future.successful(NotModified.withHeaders("ETag" -> etag))
+    )
+  }
+
+  def checkFresh(entity: E)(onStale: => Result): Result = {
+    compareEtag(entity).fold(onStale)(
+      etag => NotModified.withHeaders("ETag" -> etag)
+    )
+  }
+
+  private def compareEtag(entity: E) = request.headers.get("If-None-Match").filter(e => e == entity.etag)
+}