feat: support limit param in reverse search

lib/philomena/duplicate_reports.ex

@@ -25,7 +25,7 @@ defmodule Philomena.DuplicateReports do
     end)
   end
 
-  def duplicates_of(intensities, aspect_ratio, dist \\ 0.25, aspect_dist \\ 0.05) do
+  def duplicates_of(intensities, aspect_ratio, dist \\ 0.25, aspect_dist \\ 0.05, limit \\ 10) do
     # for each color channel
     dist = dist * 3
 
@@ -39,7 +39,7 @@ defmodule Philomena.DuplicateReports do
       where:
         i.image_aspect_ratio >= ^(aspect_ratio - aspect_dist) and
           i.image_aspect_ratio <= ^(aspect_ratio + aspect_dist),
-      limit: 10
+      limit: ^limit
   end
 
   @doc """

lib/philomena_web/controllers/api/json/search/reverse_controller.ex

@@ -13,6 +13,7 @@ defmodule PhilomenaWeb.Api.Json.Search.ReverseController do
     images =
       image_params
       |> Map.put("distance", conn.params["distance"])
+      |> Map.put("limit", conn.params["limit"])
       |> ImageReverse.images()
 
     interactions = Interactions.user_interactions(images, user)

lib/philomena_web/image_reverse.ex

@@ -18,8 +18,9 @@ defmodule PhilomenaWeb.ImageReverse do
         {width, height} = analysis.dimensions
         aspect = width / height
         dist = normalize_dist(image_params)
+        limit = parse_limit(image_params)
 
-        DuplicateReports.duplicates_of(intensities, aspect, dist, dist)
+        DuplicateReports.duplicates_of(intensities, aspect, dist, dist, limit)
         |> preload([:user, :intensity, [:sources, tags: :aliases]])
         |> Repo.all()
     end
@@ -60,4 +61,17 @@ defmodule PhilomenaWeb.ImageReverse do
         0.0
     end
   end
+
+  defp parse_limit(%{"limit" => limit}) do
+    limit
+    |> Integer.parse()
+    |> case do
+      {limit, _rest} -> limit
+      _ -> 10
+    end
+    |> max(1)
+    |> min(50)
+  end
+
+  defp parse_limit(_), do: 10
 end