feat(onboarding): Netzwerkrollen und automatisches Discovery im Onboarding hinzugefügt

- Unterstützung für Master- und Client-Rollen mit angepasster Konfiguration.
- Automatische Dienstsuche (Discovery) für Clients implementiert.
- Erweiterte UI für Drucker-, Backup- und Rollenspezifische Einstellungen.

Signed-off-by: Stefan Mogeritsch <stefan.mo.co@gmail.com>

frontend/shells/meldestelle-desktop/src/jvmMain/kotlin/at/mocode/desktop/v2/Screens.kt

@@ -10,6 +10,7 @@ import androidx.compose.foundation.text.KeyboardActions
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.automirrored.filled.ArrowForward
 import androidx.compose.material.icons.filled.*
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
@@ -29,15 +30,27 @@ import at.mocode.desktop.screens.onboarding.NetworkRole
 import at.mocode.desktop.screens.onboarding.OnboardingSettings
 import at.mocode.desktop.screens.onboarding.OnboardingValidator
 import at.mocode.frontend.core.designsystem.components.MsTextField
+import at.mocode.frontend.core.network.discovery.NetworkDiscoveryService
+import org.koin.compose.koinInject
 import javax.print.PrintServiceLookup
 import javax.swing.JFileChooser
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun OnboardingScreen(
   settings: OnboardingSettings,
   onSettingsChange: (OnboardingSettings) -> Unit,
   onContinue: (OnboardingSettings) -> Unit,
 ) {
+  var currentStep by remember { mutableStateOf(0) }
+  val discoveryService: NetworkDiscoveryService = koinInject()
+  val discoveredServices by remember { mutableStateOf(discoveryService.getDiscoveredServices()) }
+
+  // Automatische Discovery starten, wenn wir auf Schritt 0 sind
+  LaunchedEffect(currentStep) {
+    if (currentStep == 0) discoveryService.startDiscovery()
+  }
+
   DesktopThemeV2 {
     Surface(color = MaterialTheme.colorScheme.background) {
       Column(
@@ -50,27 +63,136 @@ fun OnboardingScreen(
           fontWeight = FontWeight.SemiBold
         )
         Text(
-          "Bitte konfiguriere deine lokale Instanz (Geburtsurkunde).",
+          if (currentStep == 0) "Schritt 1: Netzwerk-Rolle festlegen" else "Schritt 2: Rollenspezifische Konfiguration",
           style = MaterialTheme.typography.bodyMedium,
           color = MaterialTheme.colorScheme.onSurfaceVariant
         )
 
+        if (currentStep == 0) {
+          // PHASE 1: NETZWERK-ROLLE
+          Card(modifier = Modifier.fillMaxWidth()) {
+            Column(Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(16.dp)) {
+              Text("🌐 Netzwerk-Rolle wählen", style = MaterialTheme.typography.titleMedium)
+              Text(
+                "Wähle aus, ob dieses Gerät als Master (zentrale Datenbank) oder als Client fungiert.",
+                style = MaterialTheme.typography.bodySmall
+              )
+
+              Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                Surface(
+                  onClick = { onSettingsChange(settings.copy(networkRole = NetworkRole.MASTER)) },
+                  shape = MaterialTheme.shapes.medium,
+                  color = if (settings.networkRole == NetworkRole.MASTER) MaterialTheme.colorScheme.primaryContainer else MaterialTheme.colorScheme.surfaceVariant,
+                  modifier = Modifier.fillMaxWidth()
+                ) {
+                  Row(Modifier.padding(16.dp), verticalAlignment = Alignment.CenterVertically) {
+                    RadioButton(
+                      selected = settings.networkRole == NetworkRole.MASTER,
+                      onClick = { onSettingsChange(settings.copy(networkRole = NetworkRole.MASTER)) }
+                    )
+                    Column {
+                      Text("Master (Host)", style = MaterialTheme.typography.labelLarge)
+                      Text(
+                        "Verwaltet die zentrale Datenbank und koordiniert den Sync.",
+                        style = MaterialTheme.typography.bodySmall
+                      )
+                    }
+                  }
+                }
+
+                Surface(
+                  onClick = { onSettingsChange(settings.copy(networkRole = NetworkRole.CLIENT)) },
+                  shape = MaterialTheme.shapes.medium,
+                  color = if (settings.networkRole == NetworkRole.CLIENT) MaterialTheme.colorScheme.primaryContainer else MaterialTheme.colorScheme.surfaceVariant,
+                  modifier = Modifier.fillMaxWidth()
+                ) {
+                  Row(Modifier.padding(16.dp), verticalAlignment = Alignment.CenterVertically) {
+                    RadioButton(
+                      selected = settings.networkRole == NetworkRole.CLIENT,
+                      onClick = { onSettingsChange(settings.copy(networkRole = NetworkRole.CLIENT)) }
+                    )
+                    Column {
+                      Text("Client", style = MaterialTheme.typography.labelLarge)
+                      Text(
+                        "Verbindet sich mit einem Master und synchronisiert Daten.",
+                        style = MaterialTheme.typography.bodySmall
+                      )
+                    }
+                  }
+                }
+              }
+
+              Button(
+                onClick = { currentStep = 1 },
+                modifier = Modifier.align(Alignment.End)
+              ) {
+                Text("Weiter")
+                Icon(Icons.AutoMirrored.Filled.ArrowForward, null, Modifier.padding(start = 8.dp))
+              }
+            }
+          }
+        } else {
+          // PHASE 2: ROLLENSPEZIFISCH
           var showPw by remember { mutableStateOf(false) }
           val focusManager = LocalFocusManager.current
 
+          // 2.1 / 2.2 IDENTITÄT & SICHERHEIT
           Card(modifier = Modifier.fillMaxWidth()) {
             Column(Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(12.dp)) {
               Text("🛡️ Identität & Sicherheit", style = MaterialTheme.typography.titleMedium)
 
+              if (settings.networkRole == NetworkRole.MASTER) {
                 MsTextField(
                   value = settings.geraetName,
                   onValueChange = { onSettingsChange(settings.copy(geraetName = it)) },
                   label = "Gerätename (Pflicht)",
-              placeholder = "z. B. Meldestelle-PC-1",
+                  placeholder = "z. B. Haupt-PC",
                   modifier = Modifier.fillMaxWidth(),
                   imeAction = ImeAction.Next,
                   keyboardActions = KeyboardActions(onNext = { focusManager.moveFocus(FocusDirection.Next) })
                 )
+              } else {
+                // Client: Auswahlbox
+                var expanded by remember { mutableStateOf(false) }
+                val availableSlots =
+                  discoveredServices.flatMap { it.metadata["availableSlots"]?.split(",") ?: emptyList() }
+                    .filter { it.isNotBlank() }
+
+                ExposedDropdownMenuBox(
+                  expanded = expanded,
+                  onExpandedChange = { expanded = !expanded }
+                ) {
+                  MsTextField(
+                    value = settings.geraetName,
+                    onValueChange = {},
+                    readOnly = true,
+                    label = "Gerätename (Vom Master freigegeben)",
+                    trailingIcon = Icons.Default.ArrowDropDown,
+                    modifier = Modifier.fillMaxWidth().menuAnchor(ExposedDropdownMenuAnchorType.PrimaryNotEditable)
+                  )
+                  ExposedDropdownMenu(
+                    expanded = expanded,
+                    onDismissRequest = { expanded = false }
+                  ) {
+                    if (availableSlots.isEmpty()) {
+                      DropdownMenuItem(
+                        text = { Text("Suche nach verfügbaren Slots...") },
+                        onClick = { expanded = false }
+                      )
+                    } else {
+                      availableSlots.forEach { slot ->
+                        DropdownMenuItem(
+                          text = { Text(slot) },
+                          onClick = {
+                            onSettingsChange(settings.copy(geraetName = slot))
+                            expanded = false
+                          }
+                        )
+                      }
+                    }
+                  }
+                }
+              }
 
               MsTextField(
                 value = settings.sharedKey,
@@ -87,65 +209,11 @@ fun OnboardingScreen(
             }
           }
 
+          // 3.1 ERWARTETE GERÄTE (NUR MASTER)
+          if (settings.networkRole == NetworkRole.MASTER) {
             Card(modifier = Modifier.fillMaxWidth()) {
               Column(Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(12.dp)) {
-            Text("⚙️ Lokale Einstellungen", style = MaterialTheme.typography.titleMedium)
+                Text("📋 Erwartete Geräte (Clients)", style = MaterialTheme.typography.titleMedium)
-
-            MsTextField(
-              value = settings.backupPath,
-              onValueChange = { onSettingsChange(settings.copy(backupPath = it)) },
-              label = "💾 Datenbank-Sicherungspfad (Backup)",
-              placeholder = "Pfad zum Backup-Verzeichnis",
-              modifier = Modifier.fillMaxWidth(),
-              trailingIcon = Icons.Default.FolderOpen,
-              onTrailingIconClick = {
-                val chooser = JFileChooser()
-                chooser.fileSelectionMode = JFileChooser.DIRECTORIES_ONLY
-                chooser.dialogTitle = "Backup-Verzeichnis auswählen"
-                if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {
-                  onSettingsChange(settings.copy(backupPath = chooser.selectedFile.absolutePath))
-                }
-              },
-              imeAction = ImeAction.Next,
-              keyboardActions = KeyboardActions(onNext = { focusManager.moveFocus(FocusDirection.Next) })
-            )
-
-            Text("🌐 Netzwerk-Rolle", style = MaterialTheme.typography.labelLarge)
-            Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(16.dp)) {
-              Row(verticalAlignment = Alignment.CenterVertically) {
-                RadioButton(
-                  selected = settings.networkRole == NetworkRole.MASTER,
-                  onClick = { onSettingsChange(settings.copy(networkRole = NetworkRole.MASTER)) }
-                )
-                Text(
-                  "Master (Hostet lokale DB)",
-                  modifier = Modifier.clickable { onSettingsChange(settings.copy(networkRole = NetworkRole.MASTER)) })
-              }
-              Row(verticalAlignment = Alignment.CenterVertically) {
-                RadioButton(
-                  selected = settings.networkRole == NetworkRole.CLIENT,
-                  onClick = { onSettingsChange(settings.copy(networkRole = NetworkRole.CLIENT)) }
-                )
-                Text(
-                  "Client",
-                  modifier = Modifier.clickable { onSettingsChange(settings.copy(networkRole = NetworkRole.CLIENT)) })
-              }
-            }
-
-            Column {
-              Text("📡 Sync-Intervall: ${settings.syncInterval} Minuten", style = MaterialTheme.typography.labelLarge)
-              Slider(
-                value = settings.syncInterval.toFloat(),
-                onValueChange = { onSettingsChange(settings.copy(syncInterval = it.toInt())) },
-                valueRange = 1f..60f,
-                steps = 59,
-                modifier = Modifier.fillMaxWidth()
-              )
-            }
-
-            if (settings.networkRole == NetworkRole.MASTER) {
-              HorizontalDivider(Modifier.padding(vertical = 8.dp))
-              Text("📋 Erwartete Geräte (Clients)", style = MaterialTheme.typography.titleSmall)
                 Text(
                   "Definiere hier, welche Geräte sich in diesem Netzwerk anmelden dürfen.",
                   style = MaterialTheme.typography.bodySmall,
@@ -195,7 +263,11 @@ fun OnboardingScreen(
                       newList.removeAt(index)
                       onSettingsChange(settings.copy(expectedClients = newList))
                     }) {
-                    Icon(Icons.Default.Delete, contentDescription = "Entfernen", tint = MaterialTheme.colorScheme.error)
+                      Icon(
+                        Icons.Default.Delete,
+                        contentDescription = "Entfernen",
+                        tint = MaterialTheme.colorScheme.error
+                      )
                     }
                   }
                 }
@@ -213,6 +285,59 @@ fun OnboardingScreen(
                   Text("Gerät hinzufügen")
                 }
               }
+            }
+          }
+
+          // 4.1 / 3.2 DATENBANK-SICHERHEITSPFAD
+          Card(modifier = Modifier.fillMaxWidth()) {
+            Column(Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(12.dp)) {
+              Text(
+                if (settings.networkRole == NetworkRole.MASTER) "💾 Datenbank-Sicherheitspfad" else "💾 Lokaler Cache-Sicherungspfad",
+                style = MaterialTheme.typography.titleMedium
+              )
+
+              MsTextField(
+                value = settings.backupPath,
+                onValueChange = { onSettingsChange(settings.copy(backupPath = it)) },
+                label = "Pfad auswählen",
+                placeholder = "Verzeichnis für Backups/Cache",
+                modifier = Modifier.fillMaxWidth(),
+                trailingIcon = Icons.Default.FolderOpen,
+                onTrailingIconClick = {
+                  val chooser = JFileChooser()
+                  chooser.fileSelectionMode = JFileChooser.DIRECTORIES_ONLY
+                  chooser.dialogTitle = "Verzeichnis auswählen"
+                  if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {
+                    onSettingsChange(settings.copy(backupPath = chooser.selectedFile.absolutePath))
+                  }
+                },
+                imeAction = ImeAction.Next,
+                keyboardActions = KeyboardActions(onNext = { focusManager.moveFocus(FocusDirection.Next) })
+              )
+            }
+          }
+
+          // 5.1 SYNC-INTERVALL (NUR MASTER)
+          if (settings.networkRole == NetworkRole.MASTER) {
+            Card(modifier = Modifier.fillMaxWidth()) {
+              Column(Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(12.dp)) {
+                Text("🔄 Sync-Intervall", style = MaterialTheme.typography.titleMedium)
+                Text("📡 Intervall: ${settings.syncInterval} Minuten", style = MaterialTheme.typography.labelLarge)
+                Slider(
+                  value = settings.syncInterval.toFloat(),
+                  onValueChange = { onSettingsChange(settings.copy(syncInterval = it.toInt())) },
+                  valueRange = 1f..60f,
+                  steps = 59,
+                  modifier = Modifier.fillMaxWidth()
+                )
+              }
+            }
+          }
+
+          // 6.1 / 4.2 DRUCKER
+          Card(modifier = Modifier.fillMaxWidth()) {
+            Column(Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(12.dp)) {
+              Text("🖨️ Drucker", style = MaterialTheme.typography.titleMedium)
 
               var showPrinterDialog by remember { mutableStateOf(false) }
               val availablePrinters = remember {
@@ -222,7 +347,7 @@ fun OnboardingScreen(
               MsTextField(
                 value = settings.defaultPrinter,
                 onValueChange = { onSettingsChange(settings.copy(defaultPrinter = it)) },
-              label = "🖨️ Standard-Drucker",
+                label = "Standard-Drucker",
                 placeholder = "Name des Standard-Druckers",
                 modifier = Modifier.fillMaxWidth(),
                 trailingIcon = Icons.Default.Print,
@@ -253,10 +378,7 @@ fun OnboardingScreen(
                               .padding(vertical = 12.dp, horizontal = 8.dp),
                             verticalAlignment = Alignment.CenterVertically
                           ) {
-                          RadioButton(
+                            RadioButton(selected = settings.defaultPrinter == printer, onClick = null)
-                            selected = settings.defaultPrinter == printer,
-                            onClick = null
-                          )
                             Spacer(Modifier.width(8.dp))
                             Text(printer)
                           }
@@ -264,31 +386,31 @@ fun OnboardingScreen(
                       }
                     }
                   },
-                confirmButton = {
+                  confirmButton = { TextButton(onClick = { showPrinterDialog = false }) { Text("Schließen") } }
-                  TextButton(onClick = { showPrinterDialog = false }) {
-                    Text("Schließen")
-                  }
-                }
                 )
               }
             }
           }
 
-        val canContinue = OnboardingValidator.canContinue(settings)
+          Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.CenterVertically
+          ) {
+            TextButton(onClick = { currentStep = 0 }) {
+              Icon(Icons.AutoMirrored.Filled.ArrowBack, null)
+              Spacer(Modifier.width(8.dp))
+              Text("Zurück zur Rollenauswahl")
+            }
+
             Button(
               onClick = { onContinue(settings) },
-          enabled = canContinue,
+              enabled = OnboardingValidator.canContinue(settings)
-          modifier = Modifier.align(Alignment.End)
             ) {
-          Text("Konfiguration speichern & starten")
+              Text("Konfiguration abschließen")
+              Icon(Icons.Default.Check, null, Modifier.padding(start = 8.dp))
+            }
           }
-
-        if (!canContinue) {
-          Text(
-            "Bitte alle Pflichtfelder korrekt ausfüllen (Name min. 3, Key min. 8, Backup-Pfad gesetzt).",
-            color = MaterialTheme.colorScheme.error,
-            style = MaterialTheme.typography.labelSmall
-          )
         }
       }
     }