better 404 embeds

app/controllers/RelayRound.scala

@@ -124,13 +124,13 @@ final class RelayRound(
   def embedShow(ts: String, rs: String, id: RelayRoundId): EssentialAction =
     Anon:
       InEmbedContext:
-        Found(env.relay.api.byIdWithTour(id))(embedShow)
+        FoundEmbed(env.relay.api.byIdWithTour(id))(embedShow)
 
   def embedShow(rt: RoundModel.WithTour)(using EmbedContext): Fu[Result] =
     env.study.preview
       .firstId(rt.round.studyId)
       .flatMapz(env.study.api.byIdWithChapterOrFallback(rt.round.studyId, _))
-      .orNotFound: oldSc =>
+      .orNotFoundEmbed: oldSc =>
         studyC.CanView(oldSc.study)(
           for
             (sc, studyData) <- studyC.getJsonData(oldSc)

app/controllers/RelayTour.scala

@@ -173,7 +173,7 @@ final class RelayTour(env: Env, apiC: => Api, roundC: => RelayRound) extends Lil
 
   def embedShow(slug: String, id: RelayTourId) = Anon:
     InEmbedContext:
-      Found(env.relay.api.tourById(id)): tour =>
+      FoundEmbed(env.relay.api.tourById(id)): tour =>
         env.relay.listing.defaultRoundToShow
           .get(tour.id)
           .flatMap:

app/http/KeyPages.scala

@@ -41,6 +41,9 @@ final class KeyPages(val env: Env)(using Executor)
   def notFound(msg: Option[String])(using Context): Fu[Result] =
     NotFound.page(views.base.notFound(msg))
 
+  def notFoundEmbed(msg: Option[String])(using EmbedContext): Result =
+    NotFound.snip(views.base.notFoundEmbed(msg))
+
   def blacklisted(using ctx: Context): Result =
     if lila.security.Mobile.Api.requested(ctx.req) then
       Results.Unauthorized:

app/http/ResponseBuilder.scala

@@ -23,6 +23,9 @@ trait ResponseBuilder(using Executor)
   def Found[A](a: Fu[Option[A]])(f: A => Fu[Result])(using Context): Fu[Result] =
     a.flatMap(_.fold(notFound)(f))
 
+  def FoundEmbed[A](a: Fu[Option[A]])(f: A => Fu[Result])(using EmbedContext): Fu[Result] =
+    a.flatMap(_.fold(notFoundEmbed)(f))
+
   def Found[A](a: Option[A])(f: A => Fu[Result])(using Context): Fu[Result] =
     a.fold(notFound)(f)
 
@@ -41,6 +44,8 @@ trait ResponseBuilder(using Executor)
   extension [A](fua: Fu[Option[A]])
     def orNotFound(f: A => Fu[Result])(using Context): Fu[Result] =
       fua.flatMap { _.fold(notFound)(f) }
+    def orNotFoundEmbed(f: A => Fu[Result])(using EmbedContext): Fu[Result] =
+      fua.flatMap { _.fold(notFoundEmbed)(f) }
   extension [A](fua: Fu[Boolean])
     def elseNotFound(f: => Fu[Result])(using Context): Fu[Result] =
       fua.flatMap { if _ then f else notFound }
@@ -82,6 +87,10 @@ trait ResponseBuilder(using Executor)
       json = msg.fold(notFoundJson())(notFoundJson)
     )
 
+  def notFoundEmbed(using ctx: EmbedContext): Fu[Result] = notFoundEmbed(none)
+  def notFoundEmbed(msg: Option[String])(using ctx: EmbedContext): Fu[Result] =
+    keyPages.notFoundEmbed(msg)
+
   def authenticationFailed(using ctx: Context): Fu[Result] =
     negotiate(
       html = Redirect(

app/views/base/embed.scala

@@ -50,9 +50,7 @@ object embed:
       modules: EsmList = Nil,
       pageModule: Option[PageModule] = None,
       csp: Update[ContentSecurityPolicy] = identity
-  )(body: Modifier*)(using
-      ctx: EmbedContext
-  ) = lila.ui.Snippet:
+  )(body: Modifier*)(using ctx: EmbedContext) = lila.ui.Snippet:
     val allModules = modules ++ pageModule.so(module => jsPageModule(module.name))
     frag(
       page.ui.doctype,

app/views/base/notFound.scala

@@ -32,3 +32,16 @@ def notFound(msg: Option[String])(using Context) =
         )
       )
     )
+
+def notFoundEmbed(msg: Option[String])(using EmbedContext) =
+  views.base.embed.site(title = msg | "Page not found", cssKeys = List("bits.embed-not-found"))(
+    main(cls := "not-found page-small box box-pad")(
+      header(
+        h1("404"),
+        div(
+          strong("Page not found!"),
+          msg.map(em(_))
+        )
+      )
+    )
+  )

ui/bits/css/build/bits.not-found-embed.scss

@@ -0,0 +1,5 @@
+@import '../../../common/css/embed';
+@import '../../../common/css/base/util';
+@import '../../../common/css/component/box';
+
+@import '../not-found';