feat: Enhance CLI and GUI to support configurable game data directory persistence

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

apps/wolf_3d_cli/bin/main.dart

@@ -6,6 +6,7 @@ library;
 
 import 'dart:io';
 
+import 'package:args/args.dart';
 import 'package:wolf_3d_cli/cli_game_loop.dart';
 import 'package:wolf_3d_dart/wolf_3d_audio.dart';
 import 'package:wolf_3d_dart/wolf_3d_data.dart';
@@ -21,28 +22,66 @@ void exitCleanly(int code) {
   exit(code);
 }
 
-/// Launches the CLI renderer against the bundled retail asset set.
-void main() async {
-  stdout.write("Discovering game data...");
-  // Resolve the asset package relative to this executable so the CLI can run
-  // from the repo without additional configuration.
-  final scriptUri = Platform.script;
+/// Launches the CLI renderer using discoverable or user-provided game data.
+void main(List<String> arguments) async {
+  final argParser = ArgParser()
+    ..addOption(
+      'data-directory',
+      abbr: 'd',
+      valueHelp: 'path',
+      help: 'Directory containing Wolf3D data files.',
+    )
+    ..addFlag(
+      'help',
+      abbr: 'h',
+      negatable: false,
+      help: 'Show usage information.',
+    );
 
-  final targetUri = scriptUri.resolve(
-    '../../../packages/wolf_3d_assets/assets/retail',
-  );
-  final targetPath = targetUri.toFilePath();
+  late final ArgResults parsedArgs;
+  try {
+    parsedArgs = argParser.parse(arguments);
+  } on FormatException catch (e) {
+    stderr.writeln(e.message);
+    stderr.writeln('Usage: wolf_3d_cli [options]');
+    stderr.writeln(argParser.usage);
+    exitCleanly(64);
+  }
+
+  if (parsedArgs.flag('help')) {
+    stdout.writeln('Usage: wolf_3d_cli [options]');
+    stdout.writeln(argParser.usage);
+    exitCleanly(0);
+  }
+
+  final String? rawPath = parsedArgs.option('data-directory');
+  final String? dataDirectory = rawPath != null && rawPath.trim().isNotEmpty
+      ? rawPath.trim()
+      : null;
+
+  if (dataDirectory != null) {
+    stdout.write('Discovering game data in "$dataDirectory"...');
+  } else {
+    stdout.write('Discovering game data...');
+  }
 
   final availableGames = await WolfensteinLoader.discover(
-    directoryPath: targetPath,
+    directoryPath: dataDirectory,
     recursive: true,
   );
 
   if (availableGames.isEmpty) {
-    stderr.writeln('\nNo Wolf3D game files were found at: $targetPath');
-    stderr.writeln(
-      'Please provide valid game data files before starting the CLI host.',
-    );
+    if (dataDirectory == null) {
+      stderr.writeln('\nNo Wolf3D game data was discovered.');
+      stderr.writeln('Provide a game-data directory with one of these flags:');
+      stderr.writeln('  --data-directory <path>');
+      stderr.writeln('  -d <path>');
+    } else {
+      stderr.writeln('\nNo Wolf3D game files were found at: $dataDirectory');
+      stderr.writeln(
+        'Please provide valid game data files before starting the CLI host.',
+      );
+    }
     exitCleanly(1);
   }