feat: use XDG_DATA_HOME for Flatpak data directory

flatpak/com.cypherstack.campfire.yaml

@@ -10,7 +10,6 @@ finish-args:
   - --socket=fallback-x11
   - --socket=wayland
   - --device=dri
-  - --filesystem=~/.campfire
   - --talk-name=org.freedesktop.secrets
   - --talk-name=org.freedesktop.Notifications
 

flatpak/com.cypherstack.stackduo.yaml

@@ -10,7 +10,6 @@ finish-args:
   - --socket=fallback-x11
   - --socket=wayland
   - --device=dri
-  - --filesystem=~/.stackduo
   - --talk-name=org.freedesktop.secrets
   - --talk-name=org.freedesktop.Notifications
 

flatpak/com.cypherstack.stackwallet.yaml

@@ -10,7 +10,6 @@ finish-args:
   - --socket=fallback-x11
   - --socket=wayland
   - --device=dri
-  - --filesystem=~/.stackwallet
   - --talk-name=org.freedesktop.secrets
   - --talk-name=org.freedesktop.Notifications
 

lib/main.dart

@@ -24,6 +24,7 @@ import 'package:google_fonts/google_fonts.dart';
 import 'package:keyboard_dismisser/keyboard_dismisser.dart';
 import 'package:logger/logger.dart';
 import 'package:mobile_app_privacy/mobile_app_privacy.dart';
+import 'package:path/path.dart' as path;
 import 'package:path_provider/path_provider.dart';
 import 'package:window_size/window_size.dart';
 
@@ -98,6 +99,47 @@ void main(List<String> args) async {
 
   if (Util.isDesktop && args.length == 2 && args.first == "-d") {
     StackFileSystem.setDesktopOverrideDir(args.last);
+  } else if (Platform.isLinux) {
+    // Flatpak detection: use XDG_DATA_HOME instead of ~/.stackwallet.
+    final flatpakId = Platform.environment['FLATPAK_ID'];
+    if (flatpakId != null || File('/.flatpak-info').existsSync()) {
+      // Resolve the persistent data root. Prefer XDG_DATA_HOME when set.
+      // Otherwise fall back to $HOME/.local/share, but only if HOME is
+      // available. If neither is set we leave the data dir unchanged and
+      // let StackFileSystem use its default, rather than crashing.
+      final home = Platform.environment['HOME'];
+      final xdgDataHome =
+          Platform.environment['XDG_DATA_HOME'] ??
+          (home != null ? path.join(home, '.local', 'share') : null);
+
+      if (xdgDataHome != null) {
+        final flatpakDataDir = path.join(
+          xdgDataHome,
+          AppConfig.appDefaultDataDirName,
+        );
+
+        // Migration: move legacy data from $HOME/.stackwallet into the new
+        // location, but only when the legacy dir exists and the new one does
+        // not. Best-effort: never crash if the move fails.
+        if (home != null) {
+          final legacyDir = Directory(
+            path.join(home, '.${AppConfig.appDefaultDataDirName}'),
+          );
+          final newDir = Directory(flatpakDataDir);
+          if (legacyDir.existsSync() && !newDir.existsSync()) {
+            try {
+              await Directory(xdgDataHome).create(recursive: true);
+              await legacyDir.rename(newDir.path);
+            } catch (_) {
+              // If rename fails (e.g. different filesystem), fall back to
+              // using the new path anyway. The user can manually move data.
+            }
+          }
+        }
+
+        StackFileSystem.setDesktopOverrideDir(flatpakDataDir);
+      }
+    }
   }
 
   final loadCoinlibFuture = loadCoinlib();

lib/utilities/stack_file_system.dart

@@ -213,23 +213,32 @@ abstract class StackFileSystem {
       }
     }
 
-    final appDocsDir = await getApplicationDocumentsDirectory();
-    const logsDirName = "${AppConfig.prefix}_Logs";
     final Directory logsDir;
 
-    if (Platform.isIOS) {
-      logsDir = Directory(path.join(appDocsDir.path, "logs"));
-    } else if (Platform.isMacOS || Platform.isLinux || Platform.isWindows) {
-      // TODO check this is correct for macos
-      logsDir = Directory(path.join(appDocsDir.path, logsDirName));
-    } else if (Platform.isAndroid) {
-      // final dir = await wtfAndroidDocumentsPath();
-      // final logsDirPath = path.join(dir.path, logsDirName);
-      // logsDir = Directory(logsDirPath);
-
-      logsDir = Directory(path.join(appDocsDir.path, "logs"));
+    // When a desktop override dir is set (e.g. the Flatpak XDG_DATA_HOME
+    // location or the -d launch flag) keep logs under that persistent root
+    // so they follow the data directory rather than landing in the
+    // application documents directory.
+    if (_overrideDesktopDirPath != null) {
+      logsDir = Directory(path.join(_overrideDesktopDirPath!, "logs"));
     } else {
-      throw Exception("Unsupported Platform");
+      final appDocsDir = await getApplicationDocumentsDirectory();
+      const logsDirName = "${AppConfig.prefix}_Logs";
+
+      if (Platform.isIOS) {
+        logsDir = Directory(path.join(appDocsDir.path, "logs"));
+      } else if (Platform.isMacOS || Platform.isLinux || Platform.isWindows) {
+        // TODO check this is correct for macos
+        logsDir = Directory(path.join(appDocsDir.path, logsDirName));
+      } else if (Platform.isAndroid) {
+        // final dir = await wtfAndroidDocumentsPath();
+        // final logsDirPath = path.join(dir.path, logsDirName);
+        // logsDir = Directory(logsDirPath);
+
+        logsDir = Directory(path.join(appDocsDir.path, "logs"));
+      } else {
+        throw Exception("Unsupported Platform");
+      }
     }
 
     if (!logsDir.existsSync()) {