updates

lib/cobblemon_ui_web/sprite_static.ex

@@ -0,0 +1,37 @@
+defmodule CobblemonUiWeb.Plugs.SpriteStatic do
+  @moduledoc """
+  Serves cached Pokémon sprite images from the sprites cache directory.
+
+  Matches requests to `/sprites/<name>.png` and serves the corresponding
+  file from `CobblemonUi.SpriteCache.sprites_dir()`. If the file doesn't
+  exist locally, triggers an on-demand download before responding.
+  """
+
+  import Plug.Conn
+
+  def init(opts), do: opts
+
+  def call(%Plug.Conn{request_path: "/sprites/" <> filename} = conn, _opts) do
+    if String.ends_with?(filename, ".png") do
+      species = String.trim_trailing(filename, ".png")
+      CobblemonUi.SpriteCache.ensure_sprite(species)
+      path = CobblemonUi.SpriteCache.sprite_path(species)
+
+      if File.exists?(path) do
+        conn
+        |> put_resp_content_type("image/png")
+        |> put_resp_header("cache-control", "public, max-age=604800, immutable")
+        |> send_file(200, path)
+        |> halt()
+      else
+        conn
+        |> send_resp(404, "Not found")
+        |> halt()
+      end
+    else
+      conn
+    end
+  end
+
+  def call(conn, _opts), do: conn
+end