From 037bc9922c4fd90e9833358e6392ade1bd1aa84a Mon Sep 17 00:00:00 2001
From: TomTriple <mail@tomhoefer.de>
Date: Sun, 24 Sep 2023 22:03:38 +0200
Subject: [PATCH] add flash scope (#2451)

---
 zio-http/src/main/scala/zio/http/Middleware.scala | 7 +++++++
 zio-http/src/main/scala/zio/http/Request.scala    | 7 +++++++
 zio-http/src/main/scala/zio/http/Response.scala   | 3 +++
 3 files changed, 17 insertions(+)

diff --git a/zio-http/src/main/scala/zio/http/Middleware.scala b/zio-http/src/main/scala/zio/http/Middleware.scala
index 335281b09f..a6daeec390 100644
--- a/zio-http/src/main/scala/zio/http/Middleware.scala
+++ b/zio-http/src/main/scala/zio/http/Middleware.scala
@@ -243,4 +243,11 @@ object Middleware extends HandlerAspects {
         )
     }
   }
+
+  /**
+   * Creates a middleware for managing the flash scope.
+   */
+  def flashScopeHandling: HandlerAspect[Any, Unit] = Middleware.intercept { (req, resp) =>
+    req.cookie("zio-http-flash").fold(resp)(flash => resp.addCookie(Cookie.clear(flash.name)))
+  }
 }
diff --git a/zio-http/src/main/scala/zio/http/Request.scala b/zio-http/src/main/scala/zio/http/Request.scala
index 397ccf87a9..8cc9ccfe09 100644
--- a/zio-http/src/main/scala/zio/http/Request.scala
+++ b/zio-http/src/main/scala/zio/http/Request.scala
@@ -106,6 +106,13 @@ final case class Request(
    */
   def unnest(prefix: Path): Request =
     copy(url = self.url.copy(path = self.url.path.unnest(prefix)))
+
+  def cookie(name: String): Option[Cookie] =
+    header(Header.Cookie).map(_.value).flatMap(_.filter(_.name == name).headOption)
+
+  def flashMessage: Option[String] =
+    cookie("zio-http-flash").map(_.content)
+
 }
 
 object Request {
diff --git a/zio-http/src/main/scala/zio/http/Response.scala b/zio-http/src/main/scala/zio/http/Response.scala
index 75c33ed68b..4a630f4d54 100644
--- a/zio-http/src/main/scala/zio/http/Response.scala
+++ b/zio-http/src/main/scala/zio/http/Response.scala
@@ -40,6 +40,9 @@ final case class Response(
   def addCookie(cookie: Cookie.Response): Response =
     self.copy(headers = self.headers ++ Headers(Header.SetCookie(cookie)))
 
+  def addFlashMessage(message: String): Response =
+    addCookie(Cookie.Response("zio-http-flash", message))
+
   /**
    * Collects the potentially streaming body of the response into a single
    * chunk.