scoped random navigation

lib/philomena_web/controllers/image/random_controller.ex

@@ -0,0 +1,54 @@
+defmodule PhilomenaWeb.Image.RandomController do
+  use PhilomenaWeb, :controller
+
+  alias Philomena.Images.Query
+  alias Philomena.Images.Image
+  alias Philomena.ImageSorter
+
+  def index(conn, params) do
+    user = conn.assigns.current_user
+    filter = conn.assigns.compiled_filter
+
+    scope = Philomena.ImageScope.scope(conn)
+    query = query(user, params)
+    random_id = random_image_id(query, filter)
+
+    if random_id do
+      redirect(conn, to: Routes.image_path(conn, :show, random_id, scope))
+    else
+      redirect(conn, external: conn.assigns.referrer)
+    end
+  end
+
+  defp query(user, %{"q" => q}) do
+    {:ok, query} = Query.compile(user, q)
+
+    query
+  end
+  defp query(_user, _), do: %{match_all: %{}}
+
+  defp random_image_id(query, filter) do
+    sort = ImageSorter.parse_sort(%{"sf" => "random"})
+
+    Image.search_records(
+      %{
+        query: %{
+          bool: %{
+            must: List.flatten([sort.queries, query]),
+            must_not: [
+              filter,
+              %{term: %{hidden_from_users: true}}
+            ]
+          }
+        },
+        sort: sort.sorts
+      },
+      %{page_size: 1}
+    )
+    |> Enum.to_list()
+    |> unwrap()
+  end
+
+  defp unwrap([image]), do: image.id
+  defp unwrap([]), do: nil
+end

lib/philomena_web/router.ex

@@ -91,6 +91,7 @@ defmodule PhilomenaWeb.Router do
     resources "/activity", ActivityController, only: [:index]
     scope "/images", Image, as: :image do
       resources "/scrape", ScrapeController, only: [:create]
+      resources "/random", RandomController, only: [:index]
     end
     resources "/images", ImageController, only: [:index, :show, :new, :create] do
       resources "/comments", Image.CommentController, only: [:index, :show, :create]

lib/philomena_web/templates/image/_image_meta.html.slime

@@ -7,7 +7,7 @@
         i.fa.fa-chevron-up
       a.js-next href=Routes.image_navigate_path(@conn, :index, @image, [rel: "next"] ++ scope(@conn)) title="Next Image (k)"
         i.fa.fa-chevron-right
-      a.js-rand href="/" title="Random (r)"
+      a.js-rand href=Routes.image_random_path(@conn, :index, scope(@conn)) title="Random (r)"
         i.fa.fa-random
     .stretched-mobile-links
       a.interaction--fave href="#" rel="nofollow" data-image-id=@image.id

lib/philomena_web/templates/layout/_header_navigation.html.slime

@@ -1,6 +1,12 @@
 .hide-mobile
-  a.header__link href="/images"
+  .dropdown.header__dropdown
-    | Images
+    a.header__link href="/images"
+      | Images
+      span data-click-preventdefault="true"
+        i.fa.fa-caret-down<
+    .dropdown__content
+      a.header__link href="/images/random"
+        | Random
   .dropdown.header__dropdown
     a.header__link href="/activity"
       | Activity