From 24de28fe0e9b4b4ce0212beea5f1590f8a315613 Mon Sep 17 00:00:00 2001
From: Benedikt Reinartz <filmor@gmail.com>
Date: Wed, 16 Oct 2024 00:14:49 +0200
Subject: [PATCH] PoC to allow NIFs to be loaded from escripts

---
 rustler_mix/lib/rustler.ex | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/rustler_mix/lib/rustler.ex b/rustler_mix/lib/rustler.ex
index 487d8b4d..c5d7e336 100644
--- a/rustler_mix/lib/rustler.ex
+++ b/rustler_mix/lib/rustler.ex
@@ -158,13 +158,29 @@ defmodule Rustler do
         :code.purge(__MODULE__)
 
         {otp_app, path} = @load_from
+        app_dir = Application.app_dir(otp_app, path)
 
         load_path =
-          otp_app
-          |> Application.app_dir(path)
-          |> to_charlist()
+          case System.get_env("ESCRIPT_NAME") do
+            nil ->
+              app_dir
+
+            escript_path ->
+              if String.starts_with?(app_dir, escript_path) do
+                tmp = System.tmp_dir!()
+
+                :zip.extract(escript_path,
+                  file_list: [Path.join(otp_app |> Atom.to_string(), path)],
+                  cwd: tmp
+                )
+
+                Path.join(tmp, path)
+              else
+                app_dir
+              end
+          end
 
-        :erlang.load_nif(load_path, _construct_load_data())
+        :erlang.load_nif(load_path |> to_charlist(), _construct_load_data())
       end
     end
   end