Kotlin Script that get Linux System Theme based on Dbus appearance color-schema from Gnome 42, KDE and Elementary

get-theme.main.kts

@file:DependsOn("com.github.hypfvieh:dbus-java-core:4.0.0")
@file:DependsOn("com.github.hypfvieh:dbus-java-transport-jnr-unixsocket:4.0.0")
@file:DependsOn("org.jetbrains.kotlinx:kotlinx-coroutines-core-jvm:1.6.0")

import org.freedesktop.dbus.annotations.DBusInterfaceName
import org.freedesktop.dbus.connections.impl.DBusConnection
import org.freedesktop.dbus.interfaces.DBusInterface
import org.freedesktop.dbus.types.Variant

val connection = DBusConnection.getConnection(DBusConnection.DBusBusType.SESSION)

@DBusInterfaceName("org.freedesktop.portal.Settings")
interface SettingsInterface : DBusInterface {
    fun Read(namespace: String, key: String): Variant<*>
}

val settingsInterface = connection.getRemoteObject(
    "org.freedesktop.portal.Desktop",
    "/org/freedesktop/portal/desktop",
    SettingsInterface::class.java
)

val theme = settingsInterface.Read("org.freedesktop.appearance", "color-scheme")

fun recursiveVariantValue(variant: Variant<*>): Any {
    val value = variant.value
    if(value !is Variant<*>) return value
    else return recursiveVariantValue(value)
}

println(recursiveVariantValue(theme))