diff --git a/app/src/main/java/de/leongeorgi/pretixinfo/MainActivity.kt b/app/src/main/java/de/leongeorgi/pretixinfo/MainActivity.kt
index 3acda1f..b3c277a 100644
--- a/app/src/main/java/de/leongeorgi/pretixinfo/MainActivity.kt
+++ b/app/src/main/java/de/leongeorgi/pretixinfo/MainActivity.kt
@@ -2,26 +2,78 @@ package de.leongeorgi.pretixinfo
 
 import android.Manifest
 import android.content.Intent
+import android.graphics.Color
 import android.os.Bundle
 import android.util.Log
+import android.view.Menu
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import android.view.ViewManager
+import android.widget.Button
+import android.widget.TextView
 import com.fasterxml.jackson.core.JsonParseException
+import com.fasterxml.jackson.databind.exc.MismatchedInputException
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.module.kotlin.readValue
 import com.google.zxing.BarcodeFormat
 import com.google.zxing.Result
 import me.dm7.barcodescanner.zxing.ZXingScannerView
 import org.jetbrains.anko.*
 import org.jetbrains.anko.custom.ankoView
+import org.jetbrains.anko.sdk27.coroutines.onClick
 import java.io.BufferedReader
+import java.io.File
 import java.io.InputStreamReader
 
 class MainActivity : PermissionActivity(), ZXingScannerView.ResultHandler {
 
-    private val ui = MainActivityUI()
+    private val ui = MainActivityUI(this)
 
     private var eventData: Data? = null
 
+    private val paidFile by lazy {
+        File(filesDir, "paidSecrets.json").apply {
+            if (!exists()) {
+                val created = createNewFile()
+                if (created) {
+                    toast("created paidSecrets.json")
+                } else {
+                    toast("paidSecrets.json could not be created")
+                }
+            } else {
+                toast("found paidSecrets.json")
+            }
+        }
+    }
+
+
+    private fun addPaidSecret(secret: String) {
+        val newList = paidList + secret
+        dirtyList = true
+        jacksonObjectMapper().writeValue(paidFile, newList)
+    }
+    private fun removePaidSecret(secret: String) {
+        val newList = paidList - secret
+        dirtyList = true
+        jacksonObjectMapper().writeValue(paidFile, newList)
+    }
+
+    private var dirtyList: Boolean = true
+    private var cachedPaidList: Set<String> = emptySet()
+
+    val paidList: Set<String>
+        get() {
+            if (dirtyList) {
+                cachedPaidList = try {
+                    jacksonObjectMapper().readValue(paidFile)
+                } catch (e: MismatchedInputException) {
+                    emptySet()
+                }
+                dirtyList = false
+            }
+            return cachedPaidList
+        }
+
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         val intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
@@ -114,8 +166,63 @@ class MainActivity : PermissionActivity(), ZXingScannerView.ResultHandler {
         }
     }
 
+    private fun createAlertWithSecret(
+        title: String,
+        secret: String,
+        init: ViewManager.() -> Unit
+    ) = alert {
+        lateinit var titleTextView: TextView
+        lateinit var payButton: Button
+        fun isPaid() = secret in paidList
+
+        fun updateContent() {
+            titleTextView.apply {
+                text = "$title (${if (isPaid()) "bezahlt" else "ausstehend"})"
+                textColor = if (isPaid()) GREEN else YELLOW
+            }
+            payButton.text = if (isPaid()) "Auf \"ausstehend\" setzen" else "Auf \"bezahlt\" setzen"
+        }
+        customTitle {
+            titleTextView = textView {
+                textAppearance = android.R.style.TextAppearance_Material_Headline
+                horizontalPadding = dip(16)
+                topPadding = dip(8)
+            }
+        }
+        customView {
+            verticalLayout {
+                init(this)
+
+                payButton = button("Set paid") {
+                    onClick {
+                        if (isPaid()) {
+                            alert("Wirklich auf \"ausstehend\" setzen?") {
+                                yesButton {
+                                    removePaidSecret(secret)
+                                    updateContent()
+                                }
+                                noButton {  }
+                            }.show()
+                        } else {
+                            addPaidSecret(secret)
+                            updateContent()
+                        }
+                    }
+                }
+            }
+        }
+        updateContent()
+
+        okButton {
+            it.cancel()
+        }
+        onCancelled {
+            ui.scannerView.resumeCameraPreview(this@MainActivity)
+        }
+    }
+
     private fun createTextileAlert(event: Event, position: Position) = with(event) {
-        createAlert(position.item.name) {
+        createAlertWithSecret(position.item.name, position.secret) {
             verticalLayout {
                 textView("Größe: ${position.variation?.name}")
                 textView("Preis: ${"%.2f".format(position.price)} €")
@@ -127,7 +234,7 @@ class MainActivity : PermissionActivity(), ZXingScannerView.ResultHandler {
 
     private fun createTicketAlert(event: Event, position: Position) = with(event) {
         val inclusiveTextile = position.addons.find { it.item.category.name == "Inklusivtextil" }
-        createAlert(position.item.name) {
+        createAlertWithSecret(position.item.name, position.secret) {
             verticalLayout {
                 textView("Anzeigename: ${position.answers.first { it.question.question == "Anzeigename" }.answer}")
                 textView("Hochschule: ${position.answers.first { it.question.question == "Von welcher Hochschule kommst du?" }.answer}")
@@ -160,14 +267,12 @@ class MainActivity : PermissionActivity(), ZXingScannerView.ResultHandler {
         if (requestCode == CHOOSE_FILE_ID) {
 
             assert(data != null) { "The selected file is null" }
-            val t = toast("Parsing JSON…")
             val reader = BufferedReader(InputStreamReader(contentResolver.openInputStream(data?.data)))
             try {
                 val eventData = jacksonObjectMapper().readValue<Data>(reader, Data::class.java)
                 dataLoaded(eventData)
-                t.cancel()
+                toast("File imported successfully.")
             } catch (_: JsonParseException) {
-                t.cancel()
                 toast("File content is not valid JSON.")
                 finish()
             }
@@ -178,14 +283,21 @@ class MainActivity : PermissionActivity(), ZXingScannerView.ResultHandler {
 
     companion object {
         private const val CHOOSE_FILE_ID = 1337
+        private val GREEN = Color.parseColor("#43A047")
+        private val YELLOW = Color.parseColor("#F9A825")
     }
 }
 
-class MainActivityUI : AnkoComponent<MainActivity> {
+class MainActivityUI(val mainActivity: MainActivity) : AnkoComponent<MainActivity> {
     lateinit var scannerView: ZXingScannerView
 
     override fun createView(ui: AnkoContext<MainActivity>) = with(ui) {
         verticalLayout {
+            button("Bezahlte Secrets exportieren") {
+                onClick {
+                    share(mainActivity.paidList.joinToString(",\n"))
+                }
+            }
             scannerView = ankoView({ ZXingScannerView(it) }, 0) { }
             lparams(height = MATCH_PARENT)
         }