Support variants in Android Extensions (compiler plugin)

libraries/tools/kotlin-android-extensions/src/main/kotlin/org/jetbrains/kotlin/android/AndroidSubplugin.kt

@@ -19,8 +19,12 @@ package org.jetbrains.kotlin.android
 import org.jetbrains.kotlin.gradle.plugin.KotlinGradleSubplugin
 import org.gradle.api.Project
 import com.android.build.gradle.BaseExtension
+import com.android.build.gradle.api.AndroidSourceSet
 import org.gradle.api.tasks.compile.AbstractCompile
 import org.jetbrains.kotlin.gradle.plugin.SubpluginOption
+import org.w3c.dom.Document
+import java.io.File
+import javax.xml.parsers.DocumentBuilderFactory
 
 public class AndroidSubplugin : KotlinGradleSubplugin {
 
@@ -28,20 +32,37 @@ public class AndroidSubplugin : KotlinGradleSubplugin {
         val androidExtension = project.extensions.getByName("android") as? BaseExtension ?: return null
 
         val sourceSets = androidExtension.sourceSets
+
+        val pluginOptions = arrayListOf<SubpluginOption>()
+
         val mainSourceSet = sourceSets.getByName("main")
-
-        val resourceDirs = mainSourceSet.res.srcDirs
         val manifestFile = mainSourceSet.manifest.srcFile
+        val applicationPackage = androidExtension.defaultConfig.applicationId
+                ?: getApplicationPackageFromManifest(manifestFile) ?: ""
+        pluginOptions += SubpluginOption("package", applicationPackage)
 
-        if (resourceDirs.isNotEmpty()) {
-            val resourceDirOptions = resourceDirs.map { resourceDir ->
-                resourceDir.listFiles { it.isDirectory && it.name.startsWith("layout") }?.forEach { task.source(it) }
-                SubpluginOption("androidRes", resourceDir.absolutePath)
-            }
-            return listOf(SubpluginOption("androidManifest", manifestFile.absolutePath)) + resourceDirOptions
+        fun addVariant(sourceSet: AndroidSourceSet) {
+            pluginOptions += SubpluginOption("variant", sourceSet.name + ';' +
+                    mainSourceSet.res.srcDirs.joinToString(";") { it.absolutePath })
         }
 
-        return null
+        addVariant(mainSourceSet)
+
+        val flavorSourceSets = androidExtension.productFlavors.map { sourceSets.findByName(it.name) }.filterNotNull()
+        for (sourceSet in flavorSourceSets) {
+            addVariant(sourceSet)
+        }
+
+        return pluginOptions
+    }
+
+    private fun getApplicationPackageFromManifest(manifestFile: File): String? {
+        try {
+            return manifestFile.parseXml().documentElement.getAttribute("package")
+        }
+        catch (e: Exception) {
+            return null
+        }
     }
 
     override fun getPluginName() = "org.jetbrains.kotlin.android"
@@ -49,4 +70,10 @@ public class AndroidSubplugin : KotlinGradleSubplugin {
     override fun getGroupName() = "org.jetbrains.kotlin"
 
     override fun getArtifactName() = "kotlin-android-extensions"
+
+    fun File.parseXml(): Document {
+        val factory = DocumentBuilderFactory.newInstance()
+        val builder = factory.newDocumentBuilder()
+        return builder.parse(this)
+    }
 }