Improve device logout confirmation flow

app/src/main/java/net/novagamestudios/kaffeekasse/ui/login/LoginDevice.kt

@@ -335,19 +335,112 @@ private fun ConfirmLogoutDeviceDialog(
     onDismiss: () -> Unit,
     onConfirm: () -> Unit,
     modifier: Modifier = Modifier
-) = AlertDialog(
-    onDismissRequest = onDismiss,
-    confirmButton = {
-        Button(onClick = onConfirm) { Text("Ausloggen") }
-    },
-    modifier,
-    dismissButton = {
-        TextButton(onClick = onDismiss) { Text("Abbrechen") }
-    },
-    text = {
-        Text("Möchtest du das Gerät wirklich ausloggen?")
+) {
+    val toasts = remember { ToastsState() }
+    Toasts(toasts)
+
+    val target = 42
+    val minSolution = -10
+    val maxSolution = 10
+
+    fun newRandomEquation() = randomEquation(
+        target = target,
+        minSolution = minSolution,
+        maxSolution = maxSolution
+    )
+
+    var equationAndSolution by remember {
+        mutableStateOf(newRandomEquation())
     }
-)
+    val (equation, solution) = equationAndSolution
+
+    var userAnswer by remember { mutableStateOf<Float?>(null) }
+    var userAnswerIncorrect by remember { mutableStateOf(false) }
+
+    fun submitUserAnswer() {
+        if (userAnswer?.toInt() == solution) {
+            onConfirm()
+        } else {
+            userAnswerIncorrect = true
+        }
+    }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        confirmButton = {
+            Button(
+                onClick = { submitUserAnswer() },
+                enabled = userAnswer != null
+            ) { Text("Ausloggen") }
+        },
+        modifier,
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text("Abbrechen") }
+        },
+        icon = {
+            Icon(Icons.Rounded.Warning, "Achtung")
+        },
+        title = {
+            Text("Gerät wirklich ausloggen?")
+        },
+        text = {
+            ColumnCenter(Modifier.width(IntrinsicSize.Max)) {
+                Text("Bitte löse die folgende Gleichung, um fortzufahren:")
 
+                Box(Modifier.fillMaxWidth()) {
+                    Text(
+                        text = equation,
+                        modifier = Modifier.padding(24.dp).align(Alignment.Center),
+                        style = MaterialTheme.typography.titleMedium.copy(
+                            fontFamily = FontFamily.Serif
+                        )
+                    )
 
+                    IconButton(
+                        onClick = {
+                            equationAndSolution = newRandomEquation()
+                            userAnswer = null
+                            userAnswerIncorrect = false
+                        },
+                        modifier = Modifier.align(Alignment.CenterEnd)
+                    ) {
+                        Icon(Icons.Default.Refresh, "Neue Gleichung")
+                    }
+                }
 
+                var currentInput by remember { mutableStateOf("") }
+
+                LaunchedEffect(userAnswer) {
+                    if (currentInput.toIntOrNull() != userAnswer?.toInt()) {
+                        currentInput = "${userAnswer?.toInt() ?: ""}"
+                    }
+                }
+
+                OutlinedTextField(
+                    value = currentInput,
+                    onValueChange = {
+                        val sanitized = it.filter { c -> c.isDigit() || c in setOf('-', '+', '.', ',') }
+                        currentInput = sanitized
+                        userAnswer = sanitized.toIntOrNull()?.toFloat()
+                        userAnswerIncorrect = false
+                    },
+                    modifier = Modifier.defaultMinSize(minWidth = 1.dp),
+                    textStyle = LocalTextStyle.current.copy(
+                        fontFamily = FontFamily.Serif
+                    ),
+                    placeholder = { Text("?") },
+                    prefix = {
+                        Text("x = ", fontFamily = FontFamily.Serif)
+                    },
+                    isError = userAnswerIncorrect || (currentInput.isNotEmpty() && userAnswer == null),
+                    keyboardOptions = KeyboardOptions(
+                        keyboardType = KeyboardType.Number,
+                        imeAction = ImeAction.Done
+                    ),
+                    keyboardActions = KeyboardActions(onDone = { submitUserAnswer() })
+                )
+            }
+        },
+        iconContentColor = MaterialTheme.colorScheme.error
+    )
+}