fix: switch to kotlin

android/build.gradle

@@ -1,21 +1,32 @@
 // Generated by uniffi-bindgen-react-native
 
 buildscript {
+  // Buildscript is evaluated before everything else so we can't use getExtOrDefault
+  def kotlin_version = rootProject.ext.has("kotlinVersion") ? rootProject.ext.get("kotlinVersion") : project.properties["DummyLibForAndroid_kotlinVersion"]
+
   repositories {
     google()
     mavenCentral()
   }
 
   dependencies {
     classpath "com.android.tools.build:gradle:7.2.1"
+    // noinspection DifferentKotlinGradleVersion
+    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
   }
 }
 
+def reactNativeArchitectures() {
+  def value = rootProject.getProperties().get("reactNativeArchitectures")
+  return value ? value.split(",") : ["armeabi-v7a", "x86", "x86_64", "arm64-v8a"]
+}
+
 def isNewArchitectureEnabled() {
   return rootProject.hasProperty("newArchEnabled") && rootProject.getProperty("newArchEnabled") == "true"
 }
 
 apply plugin: "com.android.library"
+apply plugin: "kotlin-android"
 
 if (isNewArchitectureEnabled()) {
   apply plugin: "com.facebook.react"
@@ -63,6 +74,7 @@ android {
     externalNativeBuild {
       cmake {
         arguments '-DANDROID_STL=c++_shared'
+        abiFilters (*reactNativeArchitectures())
       }
     }
     ndk {
@@ -99,8 +111,8 @@ android {
     main {
       if (isNewArchitectureEnabled()) {
           java.srcDirs += [
-            // This is needed to build Kotlin project with NewArch enabled
-            "${project.buildDir}/../generated/java"
+            "generated/java",
+            "generated/jni"
           ]
       }
     }
@@ -112,11 +124,14 @@ repositories {
   google()
 }
 
+def kotlin_version = getExtOrDefault("kotlinVersion")
+
 dependencies {
   // For < 0.71, this will be from the local maven repo
   // For > 0.71, this will be replaced by `com.facebook.react:react-android:$version` by react gradle plugin
   //noinspection GradleDynamicVersion
   implementation "com.facebook.react:react-native:+"
+  implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
 }
 
 if (isNewArchitectureEnabled()) {

android/src/main/java/com/unomed/reactnativematrixsdk/ReactNativeMatrixSdkModule.kt

@@ -0,0 +1,43 @@
+// Generated by uniffi-bindgen-react-native
+package com.unomed.reactnativematrixsdk
+
+import com.facebook.react.bridge.ReactApplicationContext
+import com.facebook.react.module.annotations.ReactModule
+import com.facebook.react.turbomodule.core.interfaces.CallInvokerHolder
+
+@ReactModule(name = ReactNativeMatrixSdkModule.NAME)
+class ReactNativeMatrixSdkModule(reactContext: ReactApplicationContext) :
+  NativeReactNativeMatrixSdkSpec(reactContext) {
+
+  override fun getName(): String {
+    return NAME
+  }
+
+  // Two native methods implemented in cpp-adapter.cpp, and ultimately
+  // unomed-react-native-matrix-sdk.cpp
+
+  external fun nativeInstallRustCrate(runtimePointer: Long, callInvoker: CallInvokerHolder): Boolean
+  external fun nativeCleanupRustCrate(runtimePointer: Long): Boolean
+
+  override fun installRustCrate(): Boolean {
+    val context = this.reactApplicationContext
+    return nativeInstallRustCrate(
+      context.javaScriptContextHolder!!.get(),
+      context.jsCallInvokerHolder!!
+    )
+  }
+
+  override fun cleanupRustCrate(): Boolean {
+    return nativeCleanupRustCrate(
+      this.reactApplicationContext.javaScriptContextHolder!!.get()
+    )
+  }
+
+  companion object {
+    const val NAME = "ReactNativeMatrixSdk"
+
+    init {
+      System.loadLibrary("unomed-react-native-matrix-sdk")
+    }
+  }
+}

android/src/main/java/com/unomed/reactnativematrixsdk/ReactNativeMatrixSdkPackage.kt

@@ -0,0 +1,34 @@
+// Generated by uniffi-bindgen-react-native
+package com.unomed.reactnativematrixsdk
+
+import com.facebook.react.TurboReactPackage
+import com.facebook.react.bridge.NativeModule
+import com.facebook.react.bridge.ReactApplicationContext
+import com.facebook.react.module.model.ReactModuleInfo
+import com.facebook.react.module.model.ReactModuleInfoProvider
+import java.util.HashMap
+
+class ReactNativeMatrixSdkPackage : TurboReactPackage() {
+  override fun getModule(name: String, reactContext: ReactApplicationContext): NativeModule? {
+    return if (name == ReactNativeMatrixSdkModule.NAME) {
+      ReactNativeMatrixSdkModule(reactContext)
+    } else {
+      null
+    }
+  }
+
+  override fun getReactModuleInfoProvider(): ReactModuleInfoProvider {
+    return ReactModuleInfoProvider {
+      val moduleInfos: MutableMap<String, ReactModuleInfo> = HashMap()
+      moduleInfos[ReactNativeMatrixSdkModule.NAME] = ReactModuleInfo(
+        ReactNativeMatrixSdkModule.NAME,
+        ReactNativeMatrixSdkModule.NAME,
+        false,  // canOverrideExistingModule
+        false,  // needsEagerInit
+        false,  // isCxxModule
+        true // isTurboModule
+      )
+      moduleInfos
+    }
+  }
+}

package.json

@@ -37,8 +37,7 @@
     "!**/.*"
   ],
   "scripts": {
-    "ubrn:android": "yarn ubrn:android:build --and-generate && yarn ubrn:android:fix-build-gradle",
-    "ubrn:android:fix-build-gradle": "sed 's|generated/source/codegen/java|../generated/java|' android/build.gradle > android/build.gradle.new && mv android/build.gradle.new android/build.gradle",
+    "ubrn:android": "yarn ubrn:android:build --and-generate",
     "ubrn:android:build": "ubrn build android --config ubrn.yaml",
     "ubrn:android:build:release": "yarn ubrn:android:build --release",
     "ubrn:ios": "yarn ubrn:ios:build --and-generate && (cd example/ios && pod install)",