Add login next url parameter for auth redirects

lib/sso_bsn_web/live/user_login_live.ex

@@ -40,8 +40,8 @@ defmodule SsoBsnWeb.UserLoginLive do
     """
   end
 
-  def mount(_params, _session, socket) do
-    {:ok, socket |> assign(form: to_form(%{"username" => "", "remember_me" => false}), authenticating: false)}
+  def mount(params, _session, socket) do
+    {:ok, socket |> assign(form: to_form(%{"username" => "", "remember_me" => false}), authenticating: false, next: params["next"])}
   end
 
   def handle_event("login", %{"username" => username}, socket) do
@@ -57,7 +57,7 @@ defmodule SsoBsnWeb.UserLoginLive do
     case Accounts.authenticate_user(socket.assigns.challenge, params) do
       {:ok, user} -> 
         login_token = Accounts.generate_user_login_token(user)
-        {:noreply, socket |> redirect(to: ~p"/users/log_in/#{login_token}")}
+        {:noreply, socket |> redirect(to: if next = socket.assigns.next do ~p"/users/log_in/#{login_token}?next=#{next}" else ~p"/users/log_in/#{login_token}" end)}
       {:error, error} ->
         {:noreply, socket |> put_flash(:error, inspect(error))}
     end