Rewrite 'messages' to Kotlin

app/src/main/java/com/github/gotify/messages/MessagesModel.kt

@@ -0,0 +1,34 @@
+package com.github.gotify.messages
+
+import android.app.Activity
+import androidx.lifecycle.ViewModel
+import com.github.gotify.Settings
+import com.github.gotify.api.ClientFactory
+import com.github.gotify.client.ApiClient
+import com.github.gotify.client.api.MessageApi
+import com.github.gotify.messages.provider.ApplicationHolder
+import com.github.gotify.messages.provider.MessageFacade
+import com.github.gotify.messages.provider.MessageState
+import com.github.gotify.picasso.PicassoHandler
+import com.squareup.picasso.Target
+
+class MessagesModel(parentView: Activity) : ViewModel() {
+    val settings: Settings
+    val picassoHandler: PicassoHandler
+    val client: ApiClient
+    val appsHolder: ApplicationHolder
+    val messages: MessageFacade
+
+    // we need to keep the target references otherwise they get gc'ed before they can be called.
+    val targetReferences = mutableListOf<Target>()
+
+    var appId = MessageState.ALL_MESSAGES
+
+    init {
+        settings = Settings(parentView)
+        picassoHandler = PicassoHandler(parentView, settings)
+        client = ClientFactory.clientToken(settings.url(), settings.sslSettings(), settings.token())
+        appsHolder = ApplicationHolder(parentView, client)
+        messages = MessageFacade(client.createService(MessageApi::class.java), appsHolder)
+    }
+}