feat: LoTW confirmed-grids sync card — fetch confirmed QSO grids directly from ARRL LoTW (lotwreport.adi) and merge with Wavelog grids; credentials stored locally

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsDialog.kt

@@ -219,6 +219,69 @@ fun WavelogDialog(
     }
 }
 
+@Composable
+fun LoTWDialog(
+    initialSettings: com.rtbishop.look4sat.core.domain.model.LoTWSettings,
+    workedGridsCount: Int,
+    isSyncing: Boolean,
+    message: String?,
+    dismiss: () -> Unit,
+    onSave: (com.rtbishop.look4sat.core.domain.model.LoTWSettings) -> Unit,
+    onSync: () -> Unit
+) {
+    val call = rememberSaveable { mutableStateOf(initialSettings.callsign) }
+    val pass = rememberSaveable { mutableStateOf(initialSettings.password) }
+    SharedDialog(
+        title = stringResource(R.string.prefs_lotw_title),
+        onCancel = dismiss,
+        onAccept = {
+            onSave(com.rtbishop.look4sat.core.domain.model.LoTWSettings(call.value, pass.value))
+            dismiss()
+        }
+    ) {
+        OutlinedTextField(
+            value = call.value,
+            onValueChange = { call.value = it.uppercase() },
+            label = { Text(text = stringResource(id = R.string.prefs_lotw_callsign)) },
+            placeholder = { Text(text = "BA7OPF") },
+            singleLine = true,
+            modifier = Modifier.fillMaxWidth().padding(horizontal = LocalSpacing.current.large),
+        )
+        OutlinedTextField(
+            value = pass.value,
+            onValueChange = { pass.value = it },
+            label = { Text(text = stringResource(id = R.string.prefs_lotw_password)) },
+            placeholder = { Text(text = "********") },
+            visualTransformation = androidx.compose.ui.text.input.PasswordVisualTransformation(),
+            singleLine = true,
+            modifier = Modifier.fillMaxWidth().padding(horizontal = LocalSpacing.current.large),
+        )
+        Text(
+            text = stringResource(R.string.prefs_lotw_hint, workedGridsCount),
+            style = MaterialTheme.typography.bodySmall,
+            modifier = Modifier.padding(horizontal = LocalSpacing.current.large)
+        )
+        if (message != null) {
+            Text(
+                text = message,
+                color = MaterialTheme.colorScheme.error,
+                style = MaterialTheme.typography.bodySmall,
+                modifier = Modifier.padding(horizontal = LocalSpacing.current.large)
+            )
+        }
+        Row(
+            horizontalArrangement = Arrangement.End,
+            modifier = Modifier.fillMaxWidth().padding(horizontal = LocalSpacing.current.large)
+        ) {
+            TextButton(onClick = onSync, enabled = !isSyncing) {
+                Text(text = if (isSyncing) stringResource(R.string.prefs_lotw_syncing)
+                else stringResource(R.string.prefs_lotw_sync))
+            }
+        }
+        Spacer(modifier = Modifier.height(0.dp))
+    }
+}
+
 @Preview(showBackground = true)
 @Composable
 private fun TransceiversDialogPreview() {

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsScreen.kt

@@ -215,6 +215,18 @@ private fun SettingsScreen(uiState: SettingsState, onAction: (SettingsAction) ->
         )
     }
 
+    if (dialogs.lotw) {
+        LoTWDialog(
+            initialSettings = uiState.lotwSettings,
+            workedGridsCount = uiState.workedGridsCount,
+            isSyncing = uiState.lotwSyncing,
+            message = uiState.lotwMessage,
+            dismiss = { dialogs.lotw = false },
+            onSave = { onAction(SettingsAction.UpdateLoTW(it)) },
+            onSync = { onAction(SettingsAction.SyncLoTWGrids) }
+        )
+    }
+
     // URLs for top bar
     val uriHandler = LocalUriHandler.current
     val appUrl = stringResource(R.string.prefs_app_url)
@@ -325,6 +337,13 @@ private fun SettingsScreen(uiState: SettingsState, onAction: (SettingsAction) ->
                     showWavelogDialog = { dialogs.wavelog = true }
                 )
             }
+            item {
+                LoTWCard(
+                    settings = uiState.lotwSettings,
+                    workedGridsCount = uiState.workedGridsCount,
+                    showLoTWDialog = { dialogs.lotw = true }
+                )
+            }
             item { OtherCard(uiState.otherSettings, onAction) }
             item { CardCredits() }
             item(span = { GridItemSpan(maxLineSpan) }) {
@@ -600,6 +619,38 @@ private fun WavelogCard(
     }
 }
 
+@Composable
+private fun LoTWCard(
+    settings: com.rtbishop.look4sat.core.domain.model.LoTWSettings,
+    workedGridsCount: Int,
+    showLoTWDialog: () -> Unit
+) {
+    ElevatedCard(modifier = Modifier.fillMaxWidth()) {
+        Column(modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp)) {
+            Text(
+                text = stringResource(id = R.string.prefs_lotw_title),
+                color = MaterialTheme.colorScheme.primary
+            )
+            Spacer(modifier = Modifier.height(2.dp))
+            Text(
+                text = if (settings.isConfigured) {
+                    stringResource(R.string.prefs_wavelog_configured, workedGridsCount)
+                } else {
+                    stringResource(R.string.prefs_lotw_not_configured)
+                },
+                style = MaterialTheme.typography.bodySmall,
+                maxLines = 2
+            )
+            Spacer(modifier = Modifier.height(4.dp))
+            CardButton(
+                onClick = showLoTWDialog,
+                text = stringResource(id = R.string.prefs_wavelog_configure),
+                modifier = Modifier.fillMaxWidth()
+            )
+        }
+    }
+}
+
 @Composable
 private fun formatUpdateTime(updateTime: Long): String {
     val timePattern = stringResource(id = R.string.prefs_updated_time)
@@ -720,6 +771,7 @@ private class DialogVisibility {
     var bluetooth by mutableStateOf(false)
     var radioControl by mutableStateOf(false)
     var wavelog by mutableStateOf(false)
+    var lotw by mutableStateOf(false)
 }
 
 @Composable
@@ -727,12 +779,13 @@ private fun rememberDialogVisibility(): DialogVisibility {
     return rememberSaveable(saver = run {
         androidx.compose.runtime.saveable.Saver(
             save = {
-                listOf(it.position, it.locator, it.dataSources, it.network, it.bluetooth, it.radioControl, it.wavelog)
+                listOf(it.position, it.locator, it.dataSources, it.network, it.bluetooth, it.radioControl, it.wavelog, it.lotw)
             },
             restore = {
                 DialogVisibility().apply {
                     position = it[0]; locator = it[1]; dataSources = it[2]
                     network = it[3]; bluetooth = it[4]; radioControl = it[5]; wavelog = it[6]
+                    lotw = it.getOrElse(7) { false }
                 }
             }
         )

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsState.kt

@@ -59,6 +59,9 @@ data class SettingsState(
     val workedGridsCount: Int = 0,
     val wavelogSyncing: Boolean = false,
     val wavelogMessage: String? = null,
+    val lotwSettings: com.rtbishop.look4sat.core.domain.model.LoTWSettings = com.rtbishop.look4sat.core.domain.model.LoTWSettings(),
+    val lotwSyncing: Boolean = false,
+    val lotwMessage: String? = null,
     val updateChecker: UpdateCheckerState = UpdateCheckerState()
 )
 
@@ -95,6 +98,10 @@ sealed interface SettingsAction {
     data class UpdateWavelog(val settings: WavelogSettings) : SettingsAction
     data object SyncWorkedGrids : SettingsAction
 
+    // LoTW confirmed grids
+    data class UpdateLoTW(val settings: com.rtbishop.look4sat.core.domain.model.LoTWSettings) : SettingsAction
+    data object SyncLoTWGrids : SettingsAction
+
     // Update checker
     data object CheckForUpdate : SettingsAction
     data object DownloadUpdate : SettingsAction

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsViewModel.kt

@@ -41,6 +41,7 @@ class SettingsViewModel(
     private val settingsRepo: ISettingsRepo,
     private val updateRepo: IUpdateRepository,
     private val wavelogRepo: IWavelogRepository,
+    private val lotwRepo: com.rtbishop.look4sat.core.domain.repository.ILoTWRepository,
     private val apkFile: File,
     private val showToast: IShowToast
 ) : ViewModel() {
@@ -116,6 +117,11 @@ class SettingsViewModel(
                 _uiState.update { it.copy(wavelogSettings = settings) }
             }
         }
+        viewModelScope.launch {
+            settingsRepo.lotwSettings.collect { settings ->
+                _uiState.update { it.copy(lotwSettings = settings) }
+            }
+        }
     }
 
 
@@ -150,6 +156,9 @@ class SettingsViewModel(
             // Wavelog worked grids
             is SettingsAction.UpdateWavelog -> settingsRepo.updateWavelogSettings(action.settings)
             SettingsAction.SyncWorkedGrids -> syncWorkedGrids()
+            // LoTW confirmed grids
+            is SettingsAction.UpdateLoTW -> settingsRepo.updateLoTWSettings(action.settings)
+            SettingsAction.SyncLoTWGrids -> syncLoTWGrids()
             // Update checker
             SettingsAction.CheckForUpdate -> checkForUpdate()
             SettingsAction.DownloadUpdate -> downloadUpdate()
@@ -181,6 +190,28 @@ class SettingsViewModel(
         }
     }
 
+    private fun syncLoTWGrids() {
+        val settings = _uiState.value.lotwSettings
+        if (!settings.isConfigured) {
+            _uiState.update { it.copy(lotwMessage = "LoTW callsign/password not configured") }
+            return
+        }
+        _uiState.update { it.copy(lotwSyncing = true, lotwMessage = null) }
+        viewModelScope.launch {
+            val lotwGrids = lotwRepo.fetchConfirmedGrids(settings.callsign, settings.password)
+            _uiState.update { state ->
+                if (lotwGrids == null) {
+                    state.copy(lotwSyncing = false, lotwMessage = "LoTW sync failed — check callsign/password/network")
+                } else {
+                    // Merge with Wavelog grids: union of both sources, all confirmed/worked
+                    val merged = settingsRepo.getWorkedGrids() + lotwGrids
+                    settingsRepo.setWorkedGrids(merged)
+                    state.copy(lotwSyncing = false, workedGridsCount = merged.size, lotwMessage = null)
+                }
+            }
+        }
+    }
+
     // endregion
 
     // region Update checker
@@ -305,6 +336,7 @@ class SettingsViewModel(
                     settingsRepo = container.settingsRepo,
                     updateRepo = container.updateRepo,
                     wavelogRepo = container.wavelogRepo,
+                    lotwRepo = container.lotwRepo,
                     apkFile = File(context.cacheDir, "look4sat-update.apk"),
                     showToast = container.provideShowToast()
                 )