allow get-based reverse searching

lib/philomena_web/controllers/search/reverse_controller.ex

@@ -3,17 +3,39 @@ defmodule PhilomenaWeb.Search.ReverseController do
 
   alias PhilomenaWeb.ImageReverse
 
-  plug PhilomenaWeb.ScraperPlug,
-       [params_key: "image", params_name: "image"] when action in [:create]
+  plug :set_scraper_cache
+  plug PhilomenaWeb.ScraperPlug, params_key: "image", params_name: "image"
 
-  def index(conn, _params) do
+  def index(conn, params) do
+    create(conn, params)
+  end
+
+  def create(conn, %{"image" => image_params}) when is_map(image_params) do
+    images = ImageReverse.images(image_params)
+
+    render(conn, "index.html", title: "Reverse Search", images: images)
+  end
+
+  def create(conn, _params) do
     render(conn, "index.html", title: "Reverse Search", images: nil)
   end
 
-  def create(conn, %{"image" => image_params}) do
-    images = ImageReverse.images(image_params)
+  defp set_scraper_cache(conn, _opts) do
+    params =
+      conn.params
+      |> Map.put_new("image", %{})
+      |> Map.put_new("scraper_cache", conn.params["url"])
+      |> Map.put("distance", normalize_dist(conn.params))
 
-    conn
-    |> render("index.html", title: "Reverse Search", images: images)
+    %{conn | params: params}
   end
+
+  defp normalize_dist(%{"distance" => distance}) do
+    ("0" <> distance)
+    |> Float.parse()
+    |> elem(0)
+    |> Float.to_string()
+  end
+
+  defp normalize_dist(_dist), do: "0.25"
 end

lib/philomena_web/plugs/scraper_plug.ex

@@ -9,7 +9,7 @@ defmodule PhilomenaWeb.ScraperPlug do
       %{^params_name => %{^params_key => %Plug.Upload{}}} ->
         conn
 
-      %{"scraper_cache" => url} ->
+      %{"scraper_cache" => url} when not is_nil(url) ->
         Philomena.Http.get!(url, [], max_body_length: 30_000_000)
         |> maybe_fixup_params(opts, conn)
 

lib/philomena_web/templates/search/reverse/index.html.slime

@@ -3,10 +3,10 @@ h1 Reverse Search
 = form_for :image, Routes.search_reverse_path(@conn, :create), [multipart: true], fn f ->
   p
     ' Basic image similarity search. Finds uploaded images similar to the one
-    ' provided based on simple intensities and uses the median frame of GIFs;
-    ' very low contrast images (such as sketches) will produce poor results
-    ' and, regardless of contrast, results may include seemingly random images
-    ' that look very different.
+    ' provided based on simple intensities and uses the median frame of
+    ' animations; very low contrast images (such as sketches) will produce
+    ' poor results and, regardless of contrast, results may include seemingly
+    ' random images that look very different.
 
   .image-other
     #js-image-upload-previews
@@ -15,7 +15,7 @@ h1 Reverse Search
       = file_input f, :image, class: "input js-scraper"
 
     .field.field--inline
-      = url_input f, :scraper_url, class: "input input--wide js-scraper", placeholder: "Link a deviantART page, a Tumblr post, or the image directly"
+      = url_input f, :url, name: "url", class: "input input--wide js-scraper", placeholder: "Link a deviantART page, a Tumblr post, or the image directly"
       button.button.button--separate-left#js-scraper-preview type="button" title="Fetch the image at the specified URL" data-disable-with="Fetch"
         ' Fetch
 
@@ -26,7 +26,7 @@ h1 Reverse Search
   .field
     = label f, :distance, "Match distance (suggested values: between 0.2 and 0.5)"
     br
-    = number_input f, :distance, value: 0.25, min: 0, max: 1, step: 0.01, class: "input"
+    = number_input f, :distance, name: "distance", value: 0.25, min: 0, max: 1, step: 0.01, class: "input"
 
   .field
     = submit "Reverse Search", class: "button"