Featured image API route (#18)

* Add route

`/api/v1/json/features`

Shows current featured image

* Add route

`/api/v1/json/features`

Shows current featured image.

* Removed binding

* Moving this file to a more appropriate name.

* Correctly named and placed

Correctly named and placed to match its module name

* Updated per review

* Changed as per review

Renamed to `PhilomenaWeb.Api.Json.FeaturedController`
Moved to `lib/philomena_web/controllers/api/json/featured_controller.ex`

* Updated route

Route `/api/v1/json/images/featured` now uses `PhilomenaWeb.Api.Json.FeaturedController`

* like this

Co-authored-by: liamwhite <liamwhite@users.noreply.github.com>

lib/philomena_web/controllers/api/json/image/featured_controller.ex

@@ -0,0 +1,29 @@
+defmodule PhilomenaWeb.Api.Json.Image.FeaturedController do
+  use PhilomenaWeb, :controller
+
+  alias PhilomenaWeb.ImageJson
+  alias Philomena.ImageFeatures.ImageFeature
+  alias Philomena.Images.Image
+  alias Philomena.Repo
+  import Ecto.Query
+
+  def show(conn, _params) do
+    featured_image =
+      Image
+      |> join(:inner, [i], f in ImageFeature, on: [image_id: i.id])
+      |> order_by([_i, f], desc: f.created_at)
+      |> limit(1)
+      |> preload([:tags, :user, :intensity])
+      |> Repo.one()
+
+    case featured_image do
+      nil ->
+        conn
+        |> put_status(:not_found)
+        |> text("")
+
+      _ ->
+        json(conn, %{image: ImageJson.as_json(conn, featured_image)})
+    end
+  end
+end

lib/philomena_web/router.ex

@@ -95,6 +95,9 @@ defmodule PhilomenaWeb.Router do
 
   scope "/api/v1/json", PhilomenaWeb.Api.Json, as: :api_json do
     pipe_through [:accepts_json, :api, :ensure_tor_authorized]
+    scope "/images", Image, as: :image do
+      resources "/featured", FeaturedController, only: [:show], singleton: true
+    end
     resources "/images", ImageController, only: [:show]
 
     scope "/search", Search, as: :search do