Migrate native code to use Java FFM API

app/desktop/build.gradle.kts

@@ -3,6 +3,7 @@ import org.jetbrains.kotlin.org.jline.utils.OSUtils
 
 plugins {
     kotlin("jvm")
+    kotlin("plugin.serialization")
     id("org.jetbrains.compose")
 }
 
@@ -18,6 +19,7 @@ compose.desktop {
     application {
         mainClass = "dev.schlaubi.tonbrett.app.desktop.MainKt"
 
+        jvmArgs("--enable-native-access=ALL-UNNAMED", "--enable-preview")
         nativeDistributions {
             modules(
                 "java.naming" // required by logback
@@ -93,7 +95,7 @@ tasks {
             }
         }
         from(file("uwp_helper/target/release")) {
-            include("*.exe")
+            include("*.dll")
         }
         from(file("msix"))
         into(buildDir.resolve("msix-workspace"))
@@ -115,6 +117,10 @@ tasks {
         delete(buildDir.resolve("msix-workspace").resolve("update_msix_version.ps1"))
     }
 
+    withType<JavaCompile> {
+        options.compilerArgs.add("--enable-preview")
+    }
+
     afterEvaluate {
         "packageReleaseDistributionForCurrentOS" {
             if (OSUtils.IS_WINDOWS) {

app/desktop/rules.pro

@@ -19,6 +19,7 @@
 -dontwarn ch.qos.logback.**
 -dontwarn okhttp3.**
 -dontwarn io.ktor.**
+-dontwarn dev.schlaubi.tonbrett.app.desktop.NativeUtil
 
 # kmongo
 -keep class org.litote.kmongo.id.UUIDStringIdGeneratorProvider

app/desktop/src/main/java/dev/schlaubi/tonbrett/app/desktop/NativeUtil.java

@@ -0,0 +1,72 @@
+package dev.schlaubi.tonbrett.app.desktop;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.lang.foreign.*;
+import java.lang.invoke.MethodHandle;
+import java.net.URI;
+
+/**
+ * Utility class for calling {@code uwp_helper} functions.
+ * <p>
+ * Implemented in Java because {@code @PolymorphicSignature} doesn't seem to work in Kotlin
+ */
+public class NativeUtil {
+
+    private static final NativeUtil instance = new NativeUtil();
+    private final Linker linker = Linker.nativeLinker();
+    private final SymbolLookup uwpHelper = SymbolLookup.libraryLookup("uwp_helper", SegmentScope.global());
+
+    private final MethodHandle launchUriMethod = linker.downcallHandle(
+            uwpHelper.find("launch_uri").orElseThrow(),
+            FunctionDescriptor.ofVoid(ValueLayout.ADDRESS)
+    );
+
+    private final MethodHandle getAppdataFolder = linker.downcallHandle(
+            uwpHelper.find("get_appdata_folder").orElseThrow(),
+            FunctionDescriptor.ofVoid(ValueLayout.ADDRESS)
+    );
+
+    private final MethodHandle getAppdataFolderPathLength = linker.downcallHandle(
+            uwpHelper.find("get_appdata_folder_path_length").orElseThrow(),
+            FunctionDescriptor.of(ValueLayout.JAVA_LONG)
+    );
+
+    /**
+     * Tries to launch the URI using the UWP {@code Launcher}.
+     *
+     * @param uri the {@link URI} to launch
+     * @throws Throwable if an error occurs
+     */
+    public static void launchUri(@NotNull URI uri) throws Throwable {
+        try (var arena = Arena.openConfined()) {
+            var url = arena.allocateUtf8String(uri.toString());
+
+            instance.launchUriMethod.invoke(url);
+        }
+    }
+
+    private static long getAppdataFolderLength() throws Throwable{
+        return (long) instance.getAppdataFolderPathLength.invoke();
+    }
+
+    /**
+     * Tries to retrieve the current UWP app data folder.
+     *
+     * @return the absolute path to the folder
+     * @throws Throwable if an error occurrs
+     */
+    @Nullable
+    public static String getAppdataFolder() throws Throwable {
+        var length = getAppdataFolderLength();
+        if (length == 0) {
+            return null;
+        }
+        try(var arena = Arena.openConfined()) {
+            var buffer = arena.allocateArray(ValueLayout.JAVA_CHAR, length);
+            instance.getAppdataFolder.invoke(buffer);
+            return new String(buffer.toArray(ValueLayout.JAVA_CHAR));
+        }
+    }
+}

app/desktop/src/main/kotlin/AuthorizationServer.kt

@@ -1,8 +1,6 @@
 package dev.schlaubi.tonbrett.app.desktop
 
-import dev.schlaubi.tonbrett.app.api.Config
 import dev.schlaubi.tonbrett.app.api.getUrl
-import dev.schlaubi.tonbrett.app.api.saveConfig
 import dev.schlaubi.tonbrett.common.authServerPort
 import io.ktor.http.*
 import io.ktor.server.application.*

app/desktop/src/main/kotlin/ConfigBasedAppContext.kt

@@ -0,0 +1,9 @@
+package dev.schlaubi.tonbrett.app.desktop
+
+import dev.schlaubi.tonbrett.app.api.AppContext
+
+abstract class ConfigBasedAppContext : AppContext() {
+    override var token: String
+        get() = getConfig().sessionToken ?: error("Please sign in")
+        set(value) = saveConfig(Config(sessionToken = value))
+}

app/shared/src/desktopMain/kotlin/dev/schlaubi/tonbrett/app/api/ConfigFile.kt → app/desktop/src/main/kotlin/ConfigFile.kt

@@ -1,6 +1,6 @@
 @file:OptIn(ExperimentalSerializationApi::class)
 
-package dev.schlaubi.tonbrett.app.api
+package dev.schlaubi.tonbrett.app.desktop
 
 import kotlinx.serialization.EncodeDefault
 import kotlinx.serialization.ExperimentalSerializationApi
@@ -15,21 +15,16 @@ import kotlin.io.path.*
 
 private val LOG = KotlinLogging.logger { }
 
-val windowsAppDataFolder by lazy {
-    runCatching {
-        val process = ProcessBuilder()
-            .command("get_appdata_folder.exe")
-            .redirectError(ProcessBuilder.Redirect.INHERIT)
-            .start()
-        process.waitFor()
+val windowsAppDataFolder: String? by lazy {
+    val result = runCatching {
+        NativeUtil.getAppdataFolder()
+    }
 
-        // If opening this in Android Studio this is a false positive, since Android doesn't
-        // actually call this
-        @Suppress("NewApi")
-        process.inputStream.bufferedReader().readText().also {
-            LOG.debug { "AppData determined to be $it" }
-        }
-    }.getOrNull()
+    if (result.isFailure) {
+        result.exceptionOrNull()!!.printStackTrace()
+    }
+
+    result.getOrNull()
 }
 
 @Serializable

app/desktop/src/main/kotlin/Main.kt

@@ -23,7 +23,8 @@ import cafe.adriel.lyricist.LocalStrings
 import dev.schlaubi.tonbrett.app.ColorScheme
 import dev.schlaubi.tonbrett.app.ProvideImageLoader
 import dev.schlaubi.tonbrett.app.TonbrettApp
-import dev.schlaubi.tonbrett.app.api.*
+import dev.schlaubi.tonbrett.app.api.ProvideContext
+import dev.schlaubi.tonbrett.app.api.getUrl
 import dev.schlaubi.tonbrett.app.title
 import dev.schlaubi.tonbrett.client.href
 import dev.schlaubi.tonbrett.common.Route
@@ -116,7 +117,7 @@ private fun ApplicationScope.startActualApplication(
     CompositionLocalProvider(LocalWindowExceptionHandlerFactory provides exceptionHandler) {
         TonbrettWindow {
             val context = remember {
-                object : AppContext() {
+                object : ConfigBasedAppContext() {
                     override fun reAuthorize() {
                         window.isMinimized = true
                         main(reAuthorize = true, uwp = uwp) {

app/desktop/src/main/kotlin/URIUtil.kt

@@ -1,17 +1,11 @@
 package dev.schlaubi.tonbrett.app.desktop
 
-import dev.schlaubi.tonbrett.app.api.windowsAppDataFolder
 import java.awt.Desktop
 import java.net.URI
 
 fun browseUrl(url: URI) {
-    // Desktop#browse() internally uses ShellExecute, which doesn't work in UWP apps, therefore,
-    // We use a Rust binary, which calls:
-    // https://learn.microsoft.com/de-de/uwp/api/windows.system.launcher.launchuriasync?view=winrt-22621
-    if (System.getProperty("os.name").contains("windows", ignoreCase = true) && windowsAppDataFolder != null) {
-        check(Runtime.getRuntime().exec(arrayOf("url_launcher.exe", "-u", url.toString())).waitFor() == 0) {
-            "url_launcher.exe failed"
-        }
+    if (System.getProperty("os.name").contains("windows", ignoreCase = true)) {
+        NativeUtil.launchUri(url)
     } else {
         val desktop = Desktop.getDesktop()
         if (desktop.isSupported(Desktop.Action.BROWSE)) {