fix build hook

hook/build.dart

@@ -1,17 +1,34 @@
-import "dart:io";
 import "package:hooks/hooks.dart";
 import "package:code_assets/code_assets.dart";
 import "package:path/path.dart";
-import "package:ffigen/ffigen.dart";
 
 Future<void> main(List<String> args) => build(args, (input, output) async {
+  final targetOS = input.config.code.targetOS;
+  String libFileName;
+  switch (targetOS) {
+    case OS.linux:
+      libFileName = "libgomuks.so";
+      break;
+    case OS.macOS:
+      libFileName = "libgomuks.dylib";
+      break;
+    case OS.windows:
+      libFileName = "libgomuks.dll";
+      break;
+    default:
+      throw UnsupportedError("Unsupported OS: $targetOS");
+  }
+
+  final generatedFile = join("src", "third_party", "gomuks.g.dart");
   output.assets.code.add(
     CodeAsset(
       package: "nexus",
-      name: "src/third_party/gomuks.g.dart",
+      name: generatedFile,
       linkMode: DynamicLoadingBundled(),
-      file: libFile.uri,
+      file: input.packageRoot.resolve(join("build", "gomuks", libFileName)),
     ),
   );
-  output.dependencies.add(libFile.uri);
+  output.dependencies.add(
+    input.packageRoot.resolve(join("lib", generatedFile)),
+  );
 });