import "dart:io";
import "package:hooks/hooks.dart";
import "package:code_assets/code_assets.dart";

Future<void> main(List<String> args) => build(args, (input, output) async {
  final buildDir = input.packageRoot.resolve("src/");
  if (await File(buildDir.resolve("lock").toFilePath()).exists()) return;

  final codeConfig = input.config.code;
  final targetOS = codeConfig.targetOS;
  final targetArch = codeConfig.targetArchitecture;

  String libFileName;
  Map<String, String> env = {};
  switch (targetOS) {
    case OS.linux:
      libFileName = "libgomuks.so";
      break;
    case OS.macOS:
      libFileName = "libgomuks.dylib";
      final sdkRoot = await _macSdkRoot();
      final goArch = targetArch == Architecture.arm64 ? "arm64" : "amd64";
      env = {
        "GOARCH": goArch,
        "CGO_ENABLED": "1",
        "CGO_CFLAGS": "-isysroot $sdkRoot",
        "CGO_CXXFLAGS": "-isysroot $sdkRoot",
        "CGO_LDFLAGS": "-isysroot $sdkRoot",
      };
      break;
    case OS.windows:
      libFileName = "libgomuks.dll";
      break;
    case OS.android:
      libFileName = "libgomuks.so";

      if (targetArch != Architecture.arm64) {
        throw UnsupportedError(
          "only arm64 for now... got: $targetArch",
        );
      }

      final targetNdkApi = codeConfig.android.targetNdkApi;

      final ndkHome = Platform.environment["ANDROID_NDK_HOME"]
          ?? Platform.environment["ANDROID_NDK_ROOT"]
          ?? Platform.environment["NDK_HOME"];
      if (ndkHome == null) {
        throw Exception(
          "ANDROID_NDK_HOME, ANDROID_NDK_ROOT, or NDK_HOME must be set for Android builds",
        );
      }

      final hostTag = _ndkHostTag();
      final cc = "$ndkHome/toolchains/llvm/prebuilt/$hostTag/bin/aarch64-linux-android$targetNdkApi-clang";

      env = {
        "CGO_ENABLED": "1",
        "GOOS": "android",
        "GOARCH": "arm64",
        "CC": cc,
      };
      break;
    default:
      throw UnsupportedError("Unsupported OS: $targetOS");
  }

  final gomuksBuildDir = buildDir.resolve("gomuks/");
  final libFile = gomuksBuildDir.resolve("${targetArch.name}/$libFileName");

  print("Building Gomuks shared library $libFileName (${targetOS.name}/${targetArch.name}) from source...");
  final result = await Process.run("go", [
    "build",
    "-tags", "goolm",
    "-o",
    libFile.path,
    "-buildmode=c-shared",
  ], workingDirectory: gomuksBuildDir.resolve("source/pkg/ffi/").toFilePath(),
     environment: env.isNotEmpty ? env : null);

  if (result.exitCode != 0) {
    throw Exception("Failed to build Gomuks shared library\n${result.stderr}");
  }

  final generatedFile = "src/third_party/gomuks.g.dart";
  print("Adding $libFileName as asset...");
  output
    ..assets.code.add(
      CodeAsset(
        package: "nexus",
        name: generatedFile,
        linkMode: DynamicLoadingBundled(),
        file: libFile,
      ),
    )
    ..dependencies.add(libFile)
    ..dependencies.add(gomuksBuildDir);
  print("Done!");
});

Future<String> _macSdkRoot() async {
  final result = await Process.run("xcrun", ["--show-sdk-path"]);
  if (result.exitCode != 0) {
    throw Exception("Failed to find macOS SDK: ${result.stderr}");
  }
  return (result.stdout as String).trim();
}

String _ndkHostTag() {
  if (Platform.isMacOS) {
    return "darwin-x86_64";
  } else if (Platform.isLinux) {
    return "linux-x86_64";
  } else if (Platform.isWindows) {
    return "windows-x86_64";
  }
  throw UnsupportedError("Unsupported host platform for Android NDK");
}