refactor pages

frontend/app/Page.hs

@@ -0,0 +1,43 @@
+module Page
+  ( Page (..),
+    Action,
+    initialPage,
+    updatePage,
+    viewPage,
+  )
+where
+
+import Data.Bifunctor
+import Data.Default
+import Data.Function
+import Miso
+import Page.ListCollection qualified as ListCollection
+import Route (Route)
+import Route qualified as Route
+
+data Page
+  = Home
+  | ListCollection ListCollection.Model
+  deriving (Show, Eq)
+
+instance Default Page where
+  def = Home
+
+data Action
+  = HandleListCollection ListCollection.Action
+  deriving (Show, Eq)
+
+initialPage :: Route -> JSM (Either String Page)
+initialPage Route.Home = pure (Right Home)
+initialPage (Route.ListCollection c) =
+  fmap ListCollection <$> ListCollection.initialModel c
+
+updatePage :: Action -> Page -> Effect Action Page
+updatePage (HandleListCollection action) (ListCollection m) =
+  ListCollection.updateModel action m
+    & bimap HandleListCollection ListCollection
+updatePage (HandleListCollection _) p = noEff p
+
+viewPage :: Page -> View Action
+viewPage Home = text "home"
+viewPage (ListCollection m) = HandleListCollection <$> ListCollection.viewModel m