Persist settings to disk

src/main/kotlin/de/lobbenmeier/stefan/settings/business/SettingsViewModel.kt

@@ -0,0 +1,41 @@
+package de.lobbenmeier.stefan.settings.business
+
+import de.lobbenmeier.stefan.common.business.SettingsJson
+import de.lobbenmeier.stefan.updater.business.getPlatform
+import io.github.oshai.kotlinlogging.KotlinLogging
+import kotlin.io.path.exists
+import kotlin.io.path.readText
+import kotlin.io.path.writeText
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.serialization.encodeToString
+
+class SettingsViewModel {
+    private val logger = KotlinLogging.logger {}
+    private val platform = getPlatform()
+    private val settingsFile = platform.settingsFile
+
+    private val _settings = MutableStateFlow(loadSettings())
+    val settings: StateFlow<Settings>
+        get() = _settings
+
+    private fun loadSettings(): Settings {
+        if (settingsFile.exists()) {
+            logger.info { """Loading settings "$settingsFile" from $platform""" }
+            val settingsJson = settingsFile.readText()
+            return SettingsJson.decodeFromString<Settings>(settingsJson)
+        } else {
+            logger.warn { """Settings file $settingsFile not found for $platform""" }
+            return createEmptySettings()
+        }
+    }
+
+    fun saveSettings(settings: Settings) {
+        val settingsJson = SettingsJson.encodeToString(settings)
+        settingsFile.writeText(settingsJson)
+
+        _settings.value = settings
+    }
+
+    private fun createEmptySettings(): Settings = SettingsJson.decodeFromString("""{}""")
+}

src/main/kotlin/de/lobbenmeier/stefan/ui/App.kt

@@ -15,22 +15,23 @@ import de.lobbenmeier.stefan.downloadlist.model.DownloadQueue
 import de.lobbenmeier.stefan.downloadlist.ui.DownloadList
 import de.lobbenmeier.stefan.downloadlist.ui.Header
 import de.lobbenmeier.stefan.settings.business.Settings
-import de.lobbenmeier.stefan.settings.business.loadSettings
+import de.lobbenmeier.stefan.settings.business.SettingsViewModel
 import de.lobbenmeier.stefan.settings.ui.SettingsUI
 import de.lobbenmeier.stefan.updater.business.BinariesUpdater
 import de.lobbenmeier.stefan.updater.model.Binaries
 import de.lobbenmeier.stefan.updater.ui.Updater
 
 @Composable
 fun App() {
-    var settings by remember { mutableStateOf(loadSettings()) }
+    val settingsViewModel = remember { SettingsViewModel() }
+    val settings by settingsViewModel.settings.collectAsState()
     val binariesUpdater = remember { BinariesUpdater() }
     val binaries = binariesUpdater.binaries.collectAsState().value
 
     if (binaries == null) {
         Updater(binariesUpdater.downloads)
     } else {
-        MainView(settings, { settings = it }, binaries)
+        MainView(settings, settingsViewModel::saveSettings, binaries)
     }
 }