Add Prune History Option

app/src/main/java/org/cssnr/parking/MainActivity.kt

@@ -1,6 +1,7 @@
 package org.cssnr.parking
 
 import android.os.Bundle
+import android.util.Log
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
@@ -9,13 +10,20 @@ import androidx.compose.material3.Surface
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.tooling.preview.Preview
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.launch
+import org.cssnr.parking.data.HistoryRepository
+import org.cssnr.parking.data.SettingsRepository
+import org.cssnr.parking.data.db.AppDatabase
 import org.cssnr.parking.ui.ParKingApp
 import org.cssnr.parking.ui.theme.ParKingTheme
 
 class MainActivity : ComponentActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        pruneExpiredHistory()
         enableEdgeToEdge()
         setContent {
             ParKingTheme {
@@ -25,6 +33,31 @@ class MainActivity : ComponentActivity() {
             }
         }
     }
+
+    /**
+     * Deletes history older than the retention setting, once per cold start.
+     *
+     * Fire-and-forget on purpose: pruning is housekeeping nobody waits on, and
+     * a failure only leaves stale rows until the next launch, so it is logged
+     * and dropped. Disabled (null retention) skips the query entirely.
+     */
+    private fun pruneExpiredHistory() {
+        lifecycleScope.launch {
+            runCatching {
+                val context = applicationContext
+                val retention = SettingsRepository.retentionMillis(
+                    SettingsRepository(context).historyDuration.first(),
+                ) ?: return@launch
+                val removed = HistoryRepository(AppDatabase.getDatabase(context))
+                    .prune(System.currentTimeMillis() - retention)
+                Log.d(TAG, "Pruned $removed expired history items")
+            }.onFailure { Log.w(TAG, "history prune failed: ${it.message}") }
+        }
+    }
+
+    private companion object {
+        const val TAG = "MainActivity"
+    }
 }
 
 @Preview(showBackground = true)

app/src/main/java/org/cssnr/parking/data/HistoryRepository.kt

@@ -22,4 +22,11 @@ class HistoryRepository(database: AppDatabase) {
     suspend fun delete(id: Long) {
         historyDao.deleteById(id)
     }
+
+    /**
+     * Deletes every record older than [cutoff] (epoch millis) and returns how
+     * many rows went away. The caller derives [cutoff] from the retention
+     * setting; null retention (Disabled) means don't call this at all.
+     */
+    suspend fun prune(cutoff: Long): Int = historyDao.deleteOlderThan(cutoff)
 }

app/src/main/java/org/cssnr/parking/data/SettingsRepository.kt

@@ -3,11 +3,22 @@ package org.cssnr.parking.data
 import android.content.Context
 import androidx.datastore.preferences.core.booleanPreferencesKey
 import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.intPreferencesKey
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
 
 class SettingsRepository(private val context: Context) {
 
+    val historyDuration: Flow<Int> = context.parkingDataStore.data.map { preferences ->
+        preferences[HISTORY] ?: DEFAULT_HISTORY
+    }
+
+    suspend fun setHistoryDuration(index: Int) {
+        context.parkingDataStore.edit { preferences ->
+            preferences[HISTORY] = index.coerceIn(0, HISTORY_STEPS)
+        }
+    }
+
     val crashReporting: Flow<Boolean> = context.parkingDataStore.data.map { preferences ->
         preferences[CRASH_REPORTING] ?: true
     }
@@ -18,7 +29,28 @@ class SettingsRepository(private val context: Context) {
         }
     }
 
-    private companion object {
+    companion object {
+        // 0=Disabled | 1=1 week | 2=2 weeks | 3=1 month | 4=3 months | 5=6 months | 6=1 year
+        const val HISTORY_STEPS = 6
+        const val DEFAULT_HISTORY = 4
+        val HISTORY = intPreferencesKey("history")
         val CRASH_REPORTING = booleanPreferencesKey("acra.enable")
+
+        /**
+         * Retention in millis for a history index, or null to keep everything
+         * (Disabled). Months are 30-day approximations: history pruning is
+         * housekeeping, not billing, so calendar exactness buys nothing here.
+         */
+        fun retentionMillis(index: Int): Long? = when (index.coerceIn(0, HISTORY_STEPS)) {
+            1 -> 7L * DAY_MILLIS
+            2 -> 14L * DAY_MILLIS
+            3 -> 30L * DAY_MILLIS
+            4 -> 90L * DAY_MILLIS
+            5 -> 180L * DAY_MILLIS
+            6 -> 365L * DAY_MILLIS
+            else -> null
+        }
+
+        private const val DAY_MILLIS = 24L * 60 * 60 * 1000
     }
 }

app/src/main/java/org/cssnr/parking/data/db/HistoryDao.kt

@@ -22,4 +22,7 @@ interface HistoryDao {
 
     @Query("DELETE FROM history WHERE id = :id")
     suspend fun deleteById(id: Long)
+
+    @Query("DELETE FROM history WHERE timestamp < :cutoff")
+    suspend fun deleteOlderThan(cutoff: Long): Int
 }

app/src/main/java/org/cssnr/parking/ui/screens/SettingsScreen.kt

@@ -5,23 +5,29 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.BugReport
+import androidx.compose.material.icons.filled.History
 import androidx.compose.material.icons.filled.Info
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Slider
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
@@ -41,6 +47,7 @@ import org.cssnr.parking.ui.components.SettingsGroup
 import org.cssnr.parking.ui.components.SettingsTile
 import org.cssnr.parking.ui.theme.ParKingTheme
 import org.cssnr.parking.ui.viewmodel.SettingsViewModel
+import kotlin.math.roundToInt
 
 @Composable
 fun SettingsRoute(
@@ -51,9 +58,12 @@ fun SettingsRoute(
 ) {
     val context = LocalContext.current
     val acraInfoLink = stringResource(R.string.acra_info_link)
+    val historyDuration by viewModel.historyDuration.collectAsStateWithLifecycle()
     val crashReporting by viewModel.crashReporting.collectAsStateWithLifecycle()
 
     SettingsScreen(
+        historyDuration = historyDuration,
+        onHistoryDurationChange = viewModel::setHistoryDuration,
         crashReporting = crashReporting,
         onCrashReportingChange = viewModel::setCrashReporting,
         onCrashReportingMoreInfo = {
@@ -70,6 +80,8 @@ fun SettingsRoute(
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun SettingsScreen(
+    historyDuration: Int,
+    onHistoryDurationChange: (Int) -> Unit,
     crashReporting: Boolean,
     onCrashReportingChange: (Boolean) -> Unit,
     onCrashReportingMoreInfo: () -> Unit,
@@ -100,6 +112,32 @@ fun SettingsScreen(
                 .padding(innerPadding)
                 .verticalScroll(rememberScrollState()),
         ) {
+            val historyLabels = listOf(
+                stringResource(R.string.history_disabled),
+                stringResource(R.string.history_1_week),
+                stringResource(R.string.history_2_weeks),
+                stringResource(R.string.history_1_month),
+                stringResource(R.string.history_3_months),
+                stringResource(R.string.history_6_months),
+                stringResource(R.string.history_1_year),
+            )
+            SettingsGroup(
+                title = stringResource(R.string.settings_group_application),
+                tiles = listOf(
+                    SettingsTile.Custom(
+                        icon = rememberVectorPainter(Icons.Filled.History),
+                        title = stringResource(R.string.settings_history),
+                        summary = stringResource(R.string.settings_history_summary),
+                        content = {
+                            HistoryDurationSlider(
+                                value = historyDuration,
+                                labels = historyLabels,
+                                onSelect = onHistoryDurationChange,
+                            )
+                        },
+                    ),
+                ),
+            )
             SettingsGroup(
                 title = stringResource(R.string.settings_group_debug),
                 tiles = listOf(
@@ -171,9 +209,50 @@ fun SettingsScreen(
 fun SettingsScreenPreview() {
     ParKingTheme {
         SettingsScreen(
+            historyDuration = 4,
+            onHistoryDurationChange = {},
             crashReporting = true,
             onCrashReportingChange = {},
             onCrashReportingMoreInfo = {},
         )
     }
+}
+
+/**
+ * Discrete M3 slider with 7 stops:
+ * Disabled | 1 week | 2 weeks | 1 month | 3 months | 6 months | 1 year.
+ *
+ * 7 stops on 0f..6f means 5 intermediate steps, which draws the notch/tick at
+ * each stop. Persists only onValueChangeFinished to avoid DataStore writes
+ * on every drag frame.
+ */
+@Composable
+private fun HistoryDurationSlider(
+    value: Int,
+    labels: List<String>,
+    onSelect: (Int) -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val coerced = value.coerceIn(0, labels.lastIndex)
+    val valueRange = 0f..labels.lastIndex.toFloat()
+    var sliderValue by remember { mutableFloatStateOf(coerced.toFloat()) }
+    LaunchedEffect(coerced) {
+        sliderValue = coerced.toFloat()
+    }
+    Column(modifier = modifier.fillMaxWidth()) {
+        Slider(
+            value = sliderValue,
+            onValueChange = { sliderValue = it },
+            valueRange = valueRange,
+            steps = labels.size - 2,
+            onValueChangeFinished = {
+                onSelect(sliderValue.roundToInt().coerceIn(0, labels.lastIndex))
+            },
+        )
+        Text(
+            text = labels[sliderValue.roundToInt().coerceIn(0, labels.lastIndex)],
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.primary,
+        )
+    }
 }

app/src/main/java/org/cssnr/parking/ui/viewmodel/SettingsViewModel.kt

@@ -13,6 +13,19 @@ class SettingsViewModel(application: Application) : AndroidViewModel(application
 
     private val settingsRepository = SettingsRepository(application)
 
+    val historyDuration: StateFlow<Int> = settingsRepository.historyDuration
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.Eagerly,
+            initialValue = SettingsRepository.DEFAULT_HISTORY,
+        )
+
+    fun setHistoryDuration(index: Int) {
+        viewModelScope.launch {
+            settingsRepository.setHistoryDuration(index)
+        }
+    }
+
     val crashReporting: StateFlow<Boolean> = settingsRepository.crashReporting
         .stateIn(
             scope = viewModelScope,

app/src/main/res/values/strings.xml

@@ -2,9 +2,20 @@
     <string name="app_name">ParKing</string>
     <string name="settings">Settings</string>
 
+    <string name="settings_group_application">Application</string>
+    <string name="settings_history">Prune History</string>
+    <string name="settings_history_summary">How long to keep history.</string>
+    <string name="history_disabled">Disabled</string>
+    <string name="history_1_week">1 week</string>
+    <string name="history_2_weeks">2 weeks</string>
+    <string name="history_1_month">1 month</string>
+    <string name="history_3_months">3 months</string>
+    <string name="history_6_months">6 months</string>
+    <string name="history_1_year">1 year</string>
+
     <string name="settings_group_debug">Debug</string>
     <string name="settings_crash_reporting">Enable Crash Reporting</string>
-    <string name="settings_crash_reporting_summary">Send Crash Reports</string>
+    <string name="settings_crash_reporting_summary">Send crash reports.</string>
 
     <!-- About -->
     <string name="settings_group_about">About</string>
@@ -17,7 +28,7 @@
     <string name="about_visit_website">Visit Website</string>
     <string name="about_visit_website_summary">View Developer\'s Website</string>
     <string name="about_discord">Join Discord</string>
-    <string name="about_discord_summary">Chat with us on Discord</string>
+    <string name="about_discord_summary">Chat with Us on Discord</string>
     <string name="about_support_development">Support Development</string>
     <string name="about_support_development_summary">Donate on Ko-fi</string>
     <string name="acra_disable_title">Please Reconsider</string>