From 7707ebb05c6a021e730fdefdb41c2b7e8133251d Mon Sep 17 00:00:00 2001
From: YTG1234 <ytg1234@pm.me>
Date: Sat, 31 May 2025 22:16:04 +0300
Subject: [PATCH] jellyfin-mpv-shim: make sure the config file is read properly

jellyfin-mpv-shim has a bug, that causes it to not be able to read the
configuration file if it's not writeable (even though it never writes
anything).

This commit works around that by storing the actual link to the Nix
store in a different file, and making a writable copy in `conf.json`.

Ideally, this should be fixed either with a patch in nixpkgs or (even
better) upstream.
---
 modules/services/jellyfin-mpv-shim.nix | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/modules/services/jellyfin-mpv-shim.nix b/modules/services/jellyfin-mpv-shim.nix
index dd4fc5f1..037750d9 100644
--- a/modules/services/jellyfin-mpv-shim.nix
+++ b/modules/services/jellyfin-mpv-shim.nix
@@ -107,8 +107,20 @@ in
     ];
 
     xdg.configFile = {
+      # jellyfin-mpv-shim errors if the config file isn't writeable
+      # so, as a temporary workaround, we generate a hidden file (.conf.json)
+      # and make a writeable copy.
       "jellyfin-mpv-shim/conf.json" = lib.mkIf (cfg.settings != { }) {
         source = jsonFormat.generate "jellyfin-mpv-shim-conf" cfg.settings;
+        target = "jellyfin-mpv-shim/.conf.json";
+        onChange =
+          let
+            dir = "${config.xdg.configHome}/jellyfin-mpv-shim";
+          in
+          ''
+            cp --dereference ${dir}/.conf.json ${dir}/conf.json
+            chmod u+w ${dir}/conf.json
+          '';
       };
 
       "jellyfin-mpv-shim/mpv.conf" = lib.mkIf (cfg.mpvConfig != null) {