add health check button to settings screen

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

android/app/src/main/kotlin/me/hgsky/synq/ui/settings/SettingsScreen.kt

@@ -2,15 +2,20 @@ package me.hgsky.synq.ui.settings
 
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material3.Button
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
@@ -21,7 +26,9 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.viewmodel.compose.viewModel
 import androidx.navigation.NavController
@@ -31,6 +38,7 @@ import me.hgsky.synq.data.SynqSettings
 @Composable
 fun SettingsScreen(nav: NavController, vm: SettingsViewModel = viewModel()) {
     val saved by vm.settings.collectAsState()
+    val ping by vm.ping.collectAsState()
 
     var url by remember(saved.serverUrl) { mutableStateOf(saved.serverUrl) }
     var token by remember(saved.token) { mutableStateOf(saved.token) }
@@ -81,10 +89,46 @@ fun SettingsScreen(nav: NavController, vm: SettingsViewModel = viewModel()) {
                 label = { Text("device label") },
                 singleLine = true,
             )
-            Button(
-                onClick = ::saveAndBack,
+
+            Row(
                 modifier = Modifier.fillMaxWidth(),
-            ) { Text("save") }
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                OutlinedButton(
+                    onClick = {
+                        vm.save(SynqSettings(url.trim(), token.trim(), device.trim().ifEmpty { "android" }))
+                        vm.checkConnection(url.trim())
+                    },
+                    modifier = Modifier.weight(1f),
+                    enabled = ping !is PingState.Checking,
+                ) {
+                    if (ping is PingState.Checking) {
+                        CircularProgressIndicator(modifier = Modifier.size(16.dp), strokeWidth = 2.dp)
+                    } else {
+                        Text("check connection")
+                    }
+                }
+
+                Button(
+                    onClick = ::saveAndBack,
+                    modifier = Modifier.weight(1f),
+                ) { Text("save") }
+            }
+
+            when (val p = ping) {
+                is PingState.Ok -> Text(
+                    "✓ reachable",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = Color(0xFF2E7D32),
+                )
+                is PingState.Failed -> Text(
+                    "✗ unreachable — check URL and that server is running",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.error,
+                )
+                else -> {}
+            }
         }
     }
 }

android/app/src/main/kotlin/me/hgsky/synq/ui/settings/SettingsViewModel.kt

@@ -3,11 +3,23 @@ package me.hgsky.synq.ui.settings
 import android.app.Application
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import me.hgsky.synq.SynqApp
 import me.hgsky.synq.data.SynqSettings
+import me.hgsky.synq.data.api.SynqApiClient
+
+sealed class PingState {
+    object Idle : PingState()
+    object Checking : PingState()
+    data class Ok(val url: String) : PingState()
+    data class Failed(val url: String) : PingState()
+}
 
 class SettingsViewModel(app: Application) : AndroidViewModel(app) {
 
@@ -19,7 +31,19 @@ class SettingsViewModel(app: Application) : AndroidViewModel(app) {
         SynqSettings(),
     )
 
+    private val _ping = MutableStateFlow<PingState>(PingState.Idle)
+    val ping: StateFlow<PingState> = _ping.asStateFlow()
+
     fun save(settings: SynqSettings) {
         viewModelScope.launch { repo.save(settings) }
     }
+
+    fun checkConnection(url: String) {
+        if (_ping.value is PingState.Checking) return
+        viewModelScope.launch(Dispatchers.IO) {
+            _ping.value = PingState.Checking
+            val ok = SynqApiClient().checkHealth(url.trim())
+            _ping.value = if (ok) PingState.Ok(url) else PingState.Failed(url)
+        }
+    }
 }