From 3d863b5fe6e415351ce646ff06f47914fff1bb52 Mon Sep 17 00:00:00 2001
From: Local Dev <dev@localhost>
Date: Sun, 4 Oct 2026 22:41:10 +0200
Subject: [PATCH] Pithos on Linux desktops: per-user s3d paths

s3d's Linux defaults (/etc/s3d/s3d.yml, /var/lib/s3d) are for a system
service; a desktop user cannot write them, so the desktop app could
never create its config. When no system config exists and those places
are not writable, Pithos uses ~/.config/s3d/s3d.yml and
~/.local/share/s3d (XDG), and writes the directory into the new config
so s3d itself, started with S3D_CONFIG_FILE, uses the same place.
---
 core/config.js |  4 +++-
 core/paths.js  | 28 ++++++++++++++++++++++++++--
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/core/config.js b/core/config.js
index 472917c..da76676 100644
--- a/core/config.js
+++ b/core/config.js
@@ -5,7 +5,7 @@ import fs from 'node:fs';
 import path from 'node:path';
 import crypto from 'node:crypto';
 import YAML from 'yaml';
-import { defaultDataDir } from './paths.js';
+import { defaultDataDir, linuxUserMode } from './paths.js';
 
 // Fields the settings form exposes, as dotted yaml paths. Anything else in the
 // file is left untouched.
@@ -71,6 +71,8 @@ export function ensureConfig(file) {
     apiAddress: DEFAULTS.apiAddress,
     adminAddress: DEFAULTS.adminAddress,
     adminPassword: randomPassword(),
+    // s3d itself would fall back to /var/lib/s3d, which this user cannot write
+    ...(linuxUserMode() ? { directory: defaultDataDir() } : {}),
   });
 }
 
diff --git a/core/paths.js b/core/paths.js
index f9fa995..2717072 100644
--- a/core/paths.js
+++ b/core/paths.js
@@ -6,11 +6,33 @@ import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
 
+// s3d's Linux defaults (/etc/s3d, /var/lib/s3d) suit a system service. A
+// desktop user who cannot write there, and has no system config, gets the
+// XDG per-user places instead; new configs then name that directory
+// explicitly, so a hand-run s3d with S3D_CONFIG_FILE agrees.
+const xdg = (envName, fallback) => process.env[envName] || path.join(os.homedir(), ...fallback);
+const userConfigFile = () => path.join(xdg('XDG_CONFIG_HOME', ['.config']), 's3d', 's3d.yml');
+const userDataDir = () => path.join(xdg('XDG_DATA_HOME', ['.local', 'share']), 's3d');
+
+function writable(p) {
+  // the nearest existing folder decides whether p could be created
+  for (let d = p; ; d = path.dirname(d)) {
+    if (fs.existsSync(d)) { try { fs.accessSync(d, fs.constants.W_OK); return true; } catch { return false; } }
+    if (path.dirname(d) === d) return false;
+  }
+}
+
+export function linuxUserMode() {
+  if (process.platform === 'win32' || process.platform === 'darwin') return false;
+  if (['/etc/s3d/s3d.yml', '/var/lib/s3d/s3d.yml'].some((p) => fs.existsSync(p))) return false;
+  return !(writable('/etc/s3d') && writable('/var/lib/s3d'));
+}
+
 export function defaultDataDir() {
   switch (process.platform) {
     case 'win32': return path.join(process.env.APPDATA || path.join(os.homedir(), 'AppData', 'Roaming'), 's3d');
     case 'darwin': return path.join(os.homedir(), 'Library', 'Application Support', 's3d');
-    default: return '/var/lib/s3d';
+    default: return linuxUserMode() ? userDataDir() : '/var/lib/s3d';
   }
 }
 
@@ -20,7 +42,9 @@ export function configSearchPaths() {
   switch (process.platform) {
     case 'win32': paths.push(path.join(defaultDataDir(), 's3d.yml')); break;
     case 'darwin': paths.push(path.join(defaultDataDir(), 's3d.yml')); break;
-    default: paths.push('/etc/s3d/s3d.yml', '/var/lib/s3d/s3d.yml');
+    default:
+      if (linuxUserMode()) paths.push(userConfigFile());
+      paths.push('/etc/s3d/s3d.yml', '/var/lib/s3d/s3d.yml');
   }
   return paths;
 }