embedded dynamodb with kotlin.kt

package com.schibsted.mp.ads.sales

import com.amazonaws.services.dynamodbv2.AmazonDynamoDB
import com.amazonaws.services.dynamodbv2.local.embedded.DynamoDBEmbedded
import org.jetbrains.spek.api.dsl.Spec
import org.jetbrains.spek.api.lifecycle.CachingMode
import org.jetbrains.spek.api.lifecycle.LifecycleAware
import java.io.File
import java.nio.file.Files
import java.nio.file.Paths
import java.util.*
import java.util.Locale


fun Spec.embeddedDynamodb(): LifecycleAware<AmazonDynamoDB> {
    return memoized(CachingMode.GROUP) {
        copyNativeLibraries()
        addLibraryPath("build/nativelibs")
        val amazonDynamoDb = DynamoDBEmbedded.create().amazonDynamoDB()
        afterGroup {
            amazonDynamoDb.shutdown()
        }
        amazonDynamoDb
    }
}

fun addLibraryPath(pathToAdd: String) {
    val usrPathsField = ClassLoader::class.java.getDeclaredField("usr_paths")
    usrPathsField.isAccessible = true

    //get array of paths
    @Suppress("UNCHECKED_CAST")
    val paths = usrPathsField.get(null) as Array<String>

    //check if the path to add is already present
    paths.filter { it == pathToAdd }.forEach { return }

    //add the new path
    val newPaths = Arrays.copyOf(paths, paths.size + 1)
    newPaths[newPaths.size - 1] = pathToAdd
    usrPathsField.set(null, newPaths)
}

private fun copyNativeLibraries() {
    val classPath = System.getProperty("java.class.path", ".")
    val classPathElements = classPath
            .split(System.getProperty("path.separator")
                    .toRegex())
            .dropLastWhile { it.isEmpty() }.toTypedArray()

    File("build/nativelibs").mkdirs()

    for (element in classPathElements) {
        val filename = element.toLowerCase(Locale.UK)
        if (filename.contains("sqlite4java") && (filename.endsWith("dll") || filename.endsWith("so") || filename.endsWith("dylib"))) {
            val input = Paths.get(File(element).toURI())
            val output = Paths.get(File("build/nativelibs", File(element).name).toURI())
            Files.copy(input, output)
        }
    }
}