Bill Sync

app/src/main/java/net/helcel/cowspent/android/bill_edit/EditBillActivity.kt

@@ -331,7 +331,7 @@ class EditBillActivity : AppCompatActivity() {
                 bill.amount == viewModel.getFinalAmount() &&
                 bill.payerId == viewModel.payerId &&
                 bill.comment == viewModel.getFinalComment() &&
-                bill.repeat == viewModel.repeat &&
+                (bill.repeat ?: DBBill.NON_REPEATED) == viewModel.repeat &&
                 bill.categoryId == viewModel.categoryId &&
                 bill.paymentModeId == viewModel.paymentModeId &&
                 !owersChanged)

app/src/main/java/net/helcel/cowspent/android/main/BillsListViewActivity.kt

@@ -18,6 +18,7 @@ import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.activity.viewModels
+import androidx.annotation.VisibleForTesting
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.view.ActionMode
 import androidx.compose.material.icons.Icons
@@ -53,7 +54,9 @@ import net.helcel.cowspent.util.CospendClientUtil
 import net.helcel.cowspent.util.ExportUtil
 import net.helcel.cowspent.util.ICallback
 import net.helcel.cowspent.util.IRefreshBillsListCallback
+import net.helcel.cowspent.util.SyncSettings
 import net.helcel.cowspent.util.SupportUtil
+import net.helcel.cowspent.util.VersatileProjectSyncClient
 import java.io.IOException
 import java.text.SimpleDateFormat
 import java.util.Calendar
@@ -70,6 +73,9 @@ class BillsListViewActivity :
 
         private val TAG = BillsListViewActivity::class.java.simpleName
 
+        // Opening a project only re-syncs it if it has not synced within this window.
+        private const val SELECTED_PROJECT_SYNC_INTERVAL_MS = 60 * 1000L
+
         private const val SAVED_STATE_NAVIGATION_SELECTION = "navigationSelection"
         private const val SAVED_STATE_NAVIGATION_OPEN = "navigationOpen"
 
@@ -276,7 +282,7 @@ class BillsListViewActivity :
                             labelBillsLauncher.launch(LabelBillsActivity.createIntent(this, selectedProjectId))
                         }
                     },
-                    onRefresh = { synchronize(true) }
+                    onRefresh = { synchronize(SyncTrigger.MANUAL) }
                 )
             }
         }
@@ -330,10 +336,7 @@ class BillsListViewActivity :
         }
         viewModel.isRefreshing = false
 
-        if (db.cowspentServerSyncHelper.isSyncPossible) {
+        synchronize(SyncTrigger.APP_OPEN)
-            db.cowspentServerSyncHelper.addCallbackPull(syncCallBack)
-            synchronize()
-        }
 
         registerBroadcastReceiver()
         updateAvatarInDrawer(CowspentServerSyncHelper.isNextcloudAccountConfigured(this))
@@ -347,6 +350,9 @@ class BillsListViewActivity :
         } catch (_: RuntimeException) {
             if (DEBUG) Log.d(TAG, "RECEIVER PROBLEM, let's ignore it...")
         }
+        // The helper outlives the activity, and it only drains its pull callbacks when a task
+        // starts; drop ours so a paused activity is not retained by it.
+        db.cowspentServerSyncHelper.removeCallbackPull(syncCallBack)
         isActivityVisible = false
     }
 
@@ -373,7 +379,7 @@ class BillsListViewActivity :
         navigationSelection = Category(null, null)
         refreshLists(true)
 
-        synchronize()
+        synchronize(SyncTrigger.PROJECT_OPEN)
     }
 
     fun onManageProjectClick(projectId: Long) {
@@ -406,7 +412,7 @@ class BillsListViewActivity :
                         }
                         setupDrawerProjects()
                         refreshLists()
-                        synchronize()
+                        synchronize(SyncTrigger.PROJECT_OPEN)
                         val projectNameString = proj.name.ifEmpty { proj.remoteId }
                         showToast(this@BillsListViewActivity, getString(R.string.remove_project_confirmation, projectNameString))
                     }
@@ -421,20 +427,25 @@ class BillsListViewActivity :
         lifecycleScope.launch {
             val proj = withContext(Dispatchers.IO) { db.getProject(projectId) } ?: return@launch
             val isArchiving = !proj.isArchived
-            
+
-            val newArchivedTs = if (isArchiving) System.currentTimeMillis() / 1000 else 0L
+            val localArchivedTs = if (isArchiving) System.currentTimeMillis() / 1000 else 0L
-            
+            val remoteArchivedTs = if (isArchiving) {
+               localArchivedTs
+            } else {
+                VersatileProjectSyncClient.REMOTE_ARCHIVED_TS_UNSET
+            }
+
             withContext(Dispatchers.IO) {
                 db.updateProject(
                     projId = projectId,
-                    newArchivedTs = newArchivedTs
+                    newArchivedTs = localArchivedTs
                 )
             }
             
             if (!proj.isLocal) {
                 db.cowspentServerSyncHelper.editRemoteProject(
                     projId = projectId,
-                    newArchivedTs = newArchivedTs,
+                    newArchivedTs = remoteArchivedTs,
                     callback = object : ICallback {
                         override fun onFinish() {}
                         override fun onFinish(result: String, message: String) {
@@ -746,28 +757,60 @@ class BillsListViewActivity :
         }
     }
 
-    private fun synchronize(manual: Boolean = false) {
+    /**
+     * What prompted a sync. Only [APP_OPEN] may refresh the account and every project, and only
+     * then when the SyncOnOpen interval has elapsed; the other triggers touch the selected
+     * project alone.
+     */
+    @VisibleForTesting
+    internal enum class SyncTrigger { APP_OPEN, PROJECT_OPEN, MANUAL }
+
+    @VisibleForTesting
+    internal fun synchronize(trigger: SyncTrigger) {
         val preferences = PreferenceManager.getDefaultSharedPreferences(applicationContext)
-        val offlineMode = preferences.getBoolean(getString(R.string.pref_key_offline_mode), false)
+        // isSyncPossible is networkConnected && !offlineMode, so offline mode is already covered
-        if (offlineMode && !manual) {
+        // here - including for a manual refresh, which cannot currently override it.
-            return
+        if (!db.cowspentServerSyncHelper.isSyncPossible) return
-        }
+
+        val selectedProjectId = preferences.getLong("selected_project", 0)
+        val now = System.currentTimeMillis()
+
+        // The account and all-projects refresh belongs to opening the app, throttled by the
+        // SyncOnOpen interval so that resuming within the interval does not repeat it.
+        val intervalMinutes = SyncSettings.intervalMinutes(applicationContext)
+        val lastAccountSync = preferences.getLong(getString(R.string.pref_key_last_account_sync_timestamp), 0L)
+        val accountSyncDue = trigger == SyncTrigger.APP_OPEN &&
+            now - lastAccountSync > intervalMinutes * 60 * 1000L
+
+        lifecycleScope.launch {
+            val remoteProjects = withContext(Dispatchers.IO) { db.projects }
+                .filter { !it.isLocal && !it.isArchived }
 
-        if (db.cowspentServerSyncHelper.isSyncPossible) {
             viewModel.isRefreshing = true
-            val selectedProjectId = PreferenceManager.getDefaultSharedPreferences(applicationContext).getLong("selected_project", 0)
+            db.cowspentServerSyncHelper.addCallbackPull(syncCallBack)
-            if (selectedProjectId != 0L) {
+
-                lifecycleScope.launch {
+            val started = if (accountSyncDue) {
-                    val proj = withContext(Dispatchers.IO) { db.getProject(selectedProjectId) }
+                if (CowspentServerSyncHelper.isNextcloudAccountConfigured(applicationContext)) {
-                    if (proj != null && !proj.isLocal) {
+                    db.cowspentServerSyncHelper.runAccountProjectsSync()
-                        db.cowspentServerSyncHelper.addCallbackPull(syncCallBack)
-                        db.cowspentServerSyncHelper.scheduleSync(false, selectedProjectId, manual)
-                    } else viewModel.isRefreshing = false
                 }
-            } else viewModel.isRefreshing = false
+                remoteProjects.count {
-            if (CowspentServerSyncHelper.isNextcloudAccountConfigured(applicationContext)) {
+                    db.cowspentServerSyncHelper.scheduleSync(false, it, false) != null
-                db.cowspentServerSyncHelper.runAccountProjectsSync()
+                }
+            } else {
+                val selectedProj = remoteProjects.find { it.id == selectedProjectId }
+                val lastSync = (selectedProj?.lastSyncedTimestamp ?: 0L) * 1000L
+                val due = trigger == SyncTrigger.MANUAL ||
+                    now - lastSync > SELECTED_PROJECT_SYNC_INTERVAL_MS
+                if (selectedProj != null && due &&
+                    db.cowspentServerSyncHelper.scheduleSync(
+                        false, selectedProj, trigger == SyncTrigger.MANUAL
+                    ) != null
+                ) 1 else 0
             }
+
+            // Only a task that actually started reports back through syncCallBack, so clear
+            // the indicator here when none did - nothing else would.
+            if (started == 0) viewModel.isRefreshing = false
         }
     }
 
@@ -810,7 +853,7 @@ class BillsListViewActivity :
                     refreshLists()
                 }
                 MainConstants.BROADCAST_SYNC_PROJECT -> {
-                    synchronize()
+                    synchronize(SyncTrigger.PROJECT_OPEN)
                 }
                 MainConstants.BROADCAST_NETWORK_AVAILABLE -> {
                 }
@@ -838,7 +881,7 @@ class BillsListViewActivity :
                             refreshLists()
                             if (db.cowspentServerSyncHelper.isSyncPossible) {
                                 db.cowspentServerSyncHelper.addCallbackPull(syncCallBack)
-                                synchronize()
+                                synchronize(SyncTrigger.PROJECT_OPEN)
                             }
                         }
                     }

app/src/main/java/net/helcel/cowspent/android/settings/SettingsScreen.kt

@@ -20,6 +20,7 @@ import androidx.compose.material.IconButton
 import androidx.compose.material.MaterialTheme
 import androidx.compose.material.RadioButton
 import androidx.compose.material.Scaffold
+import androidx.compose.material.Slider
 import androidx.compose.material.Switch
 import androidx.compose.material.SwitchDefaults
 import androidx.compose.material.Text
@@ -49,6 +50,7 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
+import kotlin.math.roundToInt
 import androidx.core.content.edit
 import androidx.preference.PreferenceManager
 import net.helcel.cowspent.R
@@ -57,6 +59,7 @@ import net.helcel.cowspent.persistence.CowspentSQLiteOpenHelper
 import net.helcel.cowspent.persistence.CowspentServerSyncHelper
 import net.helcel.cowspent.util.ColorUtils
 import net.helcel.cowspent.util.Cowspent
+import net.helcel.cowspent.util.SyncSettings
 
 @Composable
 fun SettingsScreen(
@@ -81,7 +84,9 @@ fun SettingsScreen(
     val keyOfflineMode = stringResource(R.string.pref_key_offline_mode)
     val keyShowArchived = stringResource(R.string.pref_key_show_archived)
     val keyBetaFeatures = stringResource(R.string.pref_key_beta_features)
+    val keyAutoSyncOnOpen = stringResource(R.string.pref_key_auto_sync_on_open)
     val keyFillNewBillFromLast = stringResource(R.string.pref_key_fill_new_bill_from_last)
+    val keyLastAccountSync = stringResource(R.string.pref_key_last_account_sync_timestamp)
 
     val isNextcloudConfigured = CowspentServerSyncHelper.isNextcloudAccountConfigured(context)
 
@@ -127,6 +132,18 @@ fun SettingsScreen(
     var fillNewBillFromLast by remember(keyFillNewBillFromLast) {
         mutableStateOf(sharedPreferences.getBoolean(keyFillNewBillFromLast, false))
     }
+    
+    val syncIntervals = SyncSettings.INTERVAL_CHOICES_MINUTES
+    val syncIntervalLabels = listOf(
+        stringResource(R.string.pref_value_sync_1m),
+        stringResource(R.string.pref_value_sync_10m),
+        stringResource(R.string.pref_value_sync_1h),
+        stringResource(R.string.pref_value_sync_1d)
+    )
+    
+    var syncInterval by remember(keyAutoSyncOnOpen) {
+        mutableIntStateOf(SyncSettings.intervalMinutes(context))
+    }
 
     Scaffold(
         topBar = {
@@ -286,6 +303,24 @@ fun SettingsScreen(
                         }
                     }
                 )
+
+                SettingsSliderPreference(
+                    title = stringResource(R.string.settings_auto_sync_on_open),
+                    summary = stringResource(R.string.settings_auto_sync_on_open_summary),
+                    icon = Icons.Default.Sync,
+                    value = syncInterval,
+                    values = syncIntervals,
+                    labels = syncIntervalLabels,
+                    onValueChange = { newInterval ->
+                        // Slider reports every drag delta, not just the snapped steps.
+                        if (newInterval != syncInterval) {
+                            syncInterval = newInterval
+                            sharedPreferences.edit {
+                                putInt(keyAutoSyncOnOpen, newInterval)
+                            }
+                        }
+                    }
+                )
             }
 
             SettingsPreference(
@@ -464,6 +499,47 @@ fun SettingsColorPreference(
     }
 }
 
+@Composable
+fun SettingsSliderPreference(
+    title: String,
+    summary: String? = null,
+    icon: Any? = null,
+    value: Int,
+    values: List<Int>,
+    labels: List<String>,
+    onValueChange: (Int) -> Unit
+) {
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(16.dp, 8.dp)
+    ) {
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            SettingsIcon(icon)
+            Spacer(modifier = Modifier.width(32.dp))
+            Column(modifier = Modifier.weight(1f)) {
+                Text(text = title, style = MaterialTheme.typography.subtitle1)
+                if (summary != null) {
+                    Text(text = summary, style = MaterialTheme.typography.caption)
+                }
+            }
+        }
+        
+        val currentIndex = values.indexOf(value).coerceAtLeast(0)
+        val steps = (values.size - 2).coerceAtLeast(0)
+        
+        Column(modifier = Modifier.padding(start = 56.dp, top = 8.dp)) {
+            Slider(
+                value = currentIndex.toFloat(),
+                onValueChange = { onValueChange(values[it.roundToInt()]) },
+                valueRange = 0f..(values.size - 1).toFloat(),
+                steps = steps
+            )
+            Text(text = labels[currentIndex], style = MaterialTheme.typography.caption, fontWeight = FontWeight.Bold, color = MaterialTheme.colors.primary)
+        }
+    }
+}
+
 @Composable
 fun SettingsIcon(icon: Any?) {
     Box(modifier = Modifier.size(24.dp), contentAlignment = Alignment.Center) {

app/src/main/java/net/helcel/cowspent/persistence/CowspentSQLiteOpenHelper.kt

@@ -7,6 +7,7 @@ import android.database.Cursor
 import android.database.sqlite.SQLiteDatabase
 import android.database.sqlite.SQLiteOpenHelper
 import android.text.TextUtils
+import androidx.annotation.VisibleForTesting
 import androidx.annotation.WorkerThread
 import androidx.preference.PreferenceManager
 import net.helcel.cowspent.R
@@ -390,8 +391,8 @@ class CowspentSQLiteOpenHelper private constructor(val context: Context) :
 
     fun getActivatedMembersOfProject(projId: Long): List<DBMember> {
         return getMembersCustom(
-            "$key_projectid = ? AND $key_activated = 1",
+            "$key_projectid = ? AND $key_activated = 1 AND $key_state != ?",
-            arrayOf(projId.toString()),
+            arrayOf(projId.toString(), DBBill.STATE_DELETED.toString()),
             "$key_name ASC"
         )
     }
@@ -570,70 +571,54 @@ class CowspentSQLiteOpenHelper private constructor(val context: Context) :
     fun searchBills(query: CharSequence?, projectId: Long): List<DBBill> {
         val andWhere: MutableList<String> = ArrayList()
         val args: MutableList<String> = ArrayList()
-        andWhere.add("($key_projectid = $projectId)")
+        andWhere.add("($key_projectid = ?)")
+        args.add(projectId.toString())
         andWhere.add("($key_state != ${DBBill.STATE_DELETED})")
-        if (query != null) {
+
-            args.add("%$query%")
+        val terms = query?.toString()?.split("\\s+".toRegex())?.filter { it.isNotEmpty() }.orEmpty()
-            var whereStr = "($key_what LIKE ?"
+        if (terms.isNotEmpty()) {
-            if (SupportUtil.isDouble(query.toString())) {
+            val memberIdsByName = getMembersOfProject(projectId, null)
-                whereStr += " OR ($key_amount <= (? + 10) AND $key_amount >= (? - 10))"
+                .associateBy({ it.name.lowercase(Locale.ROOT) }, { it.id })
-                args.add(query.toString())
+            // Every clause appends its arguments as it is built, so args stay in the same order
-                args.add(query.toString())
+            // as the placeholders they bind to.
+            for (term in terms) {
+                andWhere.add(memberClause(term, memberIdsByName, args) ?: textClause(term, args))
             }
-            val members = getMembersOfProject(projectId, null)
-            val memberNames: MutableList<String> = ArrayList()
-            val memberIds: MutableList<Long> = ArrayList()
-            for (m in members) {
-                memberNames.add(m.name.lowercase(Locale.ROOT))
-                memberIds.add(m.id)
-            }
-            val queryStr = query.toString()
-            val words = queryStr.split("\\s+".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()
-            var nameSql = ""
-            for (word in words) {
-                if (word.startsWith("+")) {
-                    val nameQuery = word.replace("^\\+".toRegex(), "")
-                    val memberIndex = memberNames.indexOf(nameQuery.lowercase(Locale.ROOT))
-                    if (memberIndex != -1) {
-                        val searchMemberId = memberIds[memberIndex]
-                        nameSql += "($key_payer_id=?) AND "
-                        args.add(searchMemberId.toString())
-                    }
-                }
-                if (word.startsWith("-")) {
-                    val nameQuery = word.replace("^-".toRegex(), "")
-                    val memberIndex = memberNames.indexOf(nameQuery.lowercase(Locale.ROOT))
-                    if (memberIndex != -1) {
-                        val searchMemberId = memberIds[memberIndex]
-                        val joinOwer = "select $table_bills.$key_id from $table_bills inner join $table_billowers " +
-                                "where $key_member_id=? and $table_bills.$key_id=$table_billowers.$key_billId"
-                        nameSql += "($key_id IN ($joinOwer)) AND "
-                        args.add(searchMemberId.toString())
-                    }
-                }
-                if (word.startsWith("@")) {
-                    val nameQuery = word.replace("^@".toRegex(), "")
-                    val memberIndex = memberNames.indexOf(nameQuery.lowercase(Locale.ROOT))
-                    if (memberIndex != -1) {
-                        val searchMemberId = memberIds[memberIndex]
-                        nameSql += "( ($key_payer_id=?) OR "
-                        args.add(searchMemberId.toString())
-                        val joinOwer = "select $table_bills.$key_id from $table_bills inner join $table_billowers " +
-                                "where $key_member_id=? and $table_bills.$key_id=$table_billowers.$key_billId"
-                        nameSql += "($key_id IN ($joinOwer)) ) AND "
-                        args.add(searchMemberId.toString())
-                    }
-                }
-            }
-            if (nameSql != "") {
-                nameSql = nameSql.replace(" AND $".toRegex(), "")
-                whereStr += " OR ($nameSql)"
-            }
-            whereStr += ")"
-            andWhere.add(whereStr)
         }
-        val order = "$key_timestamp DESC"
+        return getBillsCustom(TextUtils.join(" AND ", andWhere), args.toTypedArray(), "$key_timestamp DESC")
-        return getBillsCustom(TextUtils.join(" AND ", andWhere), args.toTypedArray(), order)
+    }
+
+    /** Clause for a `+name`/`-name`/`@name` term, or null when the term names no member. */
+    private fun memberClause(term: String, memberIdsByName: Map<String, Long>, args: MutableList<String>): String? {
+        val prefix = term.first()
+        if (prefix != '+' && prefix != '-' && prefix != '@') return null
+        val memberId = memberIdsByName[term.substring(1).lowercase(Locale.ROOT)] ?: return null
+        val owedByMember = "SELECT $table_bills.$key_id FROM $table_bills INNER JOIN $table_billowers " +
+                "WHERE $key_member_id = ? AND $table_bills.$key_id = $table_billowers.$key_billId"
+        args.add(memberId.toString())
+        return when (prefix) {
+            '+' -> "($key_payer_id = ?)"
+            '-' -> "($key_id IN ($owedByMember))"
+            else -> {
+                args.add(memberId.toString())
+                "(($key_payer_id = ?) OR ($key_id IN ($owedByMember)))"
+            }
+        }
+    }
+
+    /** Clause matching a free text term against the description, the comment and the amount. */
+    private fun textClause(term: String, args: MutableList<String>): String {
+        val needle = "%" + term.replace("\\", "\\\\").replace("%", "\\%").replace("_", "\\_") + "%"
+        args.add(needle)
+        args.add(needle)
+        var clause = "(($key_what LIKE ? ESCAPE '\\') OR ($key_comment LIKE ? ESCAPE '\\')"
+        if (SupportUtil.isDouble(term)) {
+            clause += " OR ($key_amount <= (? + $AMOUNT_SEARCH_TOLERANCE) AND " +
+                    "$key_amount >= (? - $AMOUNT_SEARCH_TOLERANCE))"
+            args.add(term)
+            args.add(term)
+        }
+        return "$clause)"
     }
 
     @WorkerThread
@@ -1240,6 +1225,9 @@ class CowspentSQLiteOpenHelper private constructor(val context: Context) :
         )
         private const val default_order = "$key_id DESC"
 
+        /** Half width of the window a numeric search term matches, in project currency. */
+        private const val AMOUNT_SEARCH_TOLERANCE = 10
+
         @Volatile
         private var instance: CowspentSQLiteOpenHelper? = null
 
@@ -1249,5 +1237,15 @@ class CowspentSQLiteOpenHelper private constructor(val context: Context) :
                 instance ?: CowspentSQLiteOpenHelper(context.applicationContext).also { instance = it }
             }
         }
+
+        @VisibleForTesting
+        fun setInstance(helper: CowspentSQLiteOpenHelper?) {
+            instance = helper
+        }
+
+        @VisibleForTesting
+        fun resetInstance() {
+            instance = null
+        }
     }
 }

app/src/main/java/net/helcel/cowspent/persistence/CowspentServerSyncHelper.kt

@@ -8,6 +8,7 @@ import android.content.SharedPreferences
 import android.net.ConnectivityManager
 import android.os.IBinder
 import android.util.Log
+import androidx.annotation.VisibleForTesting
 import androidx.core.content.edit
 import androidx.core.graphics.toColorInt
 import androidx.preference.PreferenceManager
@@ -90,14 +91,38 @@ class CowspentServerSyncHelper private constructor(private val dbHelper: Cowspen
         }
 
     fun addCallbackPull(callback: ICallback) {
-        callbacksPull.add(callback)
+        // Callers register on every resume but the list is only drained when a task actually
+        // starts, so refuse duplicates rather than letting the same callback pile up.
+        if (!callbacksPull.contains(callback)) {
+            callbacksPull.add(callback)
+        }
     }
 
-    fun scheduleSync(onlyLocalChanges: Boolean, projId: Long, forceFullSync: Boolean = false): SyncTask? {
+    fun removeCallbackPull(callback: ICallback) {
+        callbacksPull.remove(callback)
+    }
+
+    fun scheduleSync(onlyLocalChanges: Boolean, projId: Long, forceFullSync: Boolean = false): SyncTask? =
+        scheduleSync(onlyLocalChanges, projId, forceFullSync) { dbHelper.getProject(projId) }
+
+    /**
+     * Overload for callers that already hold the project. Resolving one by id costs a query plus
+     * a blocking DataStore read and an AEAD decrypt in getProjectFromCursor, which adds up when
+     * scheduling a sync for every project at app open.
+     */
+    fun scheduleSync(onlyLocalChanges: Boolean, project: DBProject, forceFullSync: Boolean = false): SyncTask? =
+        scheduleSync(onlyLocalChanges, project.id, forceFullSync) { project }
+
+    private fun scheduleSync(
+        onlyLocalChanges: Boolean,
+        projId: Long,
+        forceFullSync: Boolean,
+        resolveProject: () -> DBProject?
+    ): SyncTask? {
         Log.d(TAG, "Sync requested (${if (onlyLocalChanges) "onlyLocalChanges" else "full"}; ${if (syncActive) "sync active" else "sync NOT active"}; forceFullSync=$forceFullSync) ...")
         updateNetworkStatus()
         if (isSyncPossible && (!syncActive || onlyLocalChanges)) {
-            val project = dbHelper.getProject(projId)
+            val project = resolveProject()
             if (project != null) {
                 Log.d(TAG, "... starting now")
                 val syncTask = SyncTask(onlyLocalChanges, project, forceFullSync)
@@ -1027,8 +1052,21 @@ class CowspentServerSyncHelper private constructor(private val dbHelper: Cowspen
             }
             var status = LoginStatus.OK
             try {
+                // Pass current project values if the new ones are null to ensure a complete project object is sent to the server
+                val currentProj = project!!
+                val finalName = (newName ?: currentProj.name).let { if (it.isBlank() || it == "null") currentProj.remoteId else it }
+                // Stay null when the project has no main currency, so the PUT omits currencyName
+                // instead of silently setting the server-side currency.
+                val finalCurrency = (newMainCurrencyName ?: currentProj.currencyName)
+                    ?.takeUnless { it.isBlank() || it == "null" }
+                
                 val response = client!!.editRemoteProject(
-                    project!!, newName, newEmail, newPassword, newMainCurrencyName, newArchivedTs
+                    currentProj,
+                    finalName,
+                    newEmail ?: currentProj.email,
+                    newPassword,
+                    finalCurrency,
+                    newArchivedTs
                 )
                 if (BillsListViewActivity.DEBUG) {
                     Log.i(TAG, "RESPONSE edit remote project : ${response.stringContent}")
@@ -1418,6 +1456,11 @@ class CowspentServerSyncHelper private constructor(private val dbHelper: Cowspen
         }
 
         private fun onPostExecute(status: LoginStatus) {
+            if (status == LoginStatus.OK) {
+                preferences.edit {
+                    putLong(appContext.getString(R.string.pref_key_last_account_sync_timestamp), System.currentTimeMillis())
+                }
+            }
             if (status != LoginStatus.OK) {
                 var errorString = appContext.getString(R.string.error_sync, appContext.getString(status.str)) + "\n\n"
                 for (errorMessage in errorMessages) {
@@ -1673,6 +1716,12 @@ class CowspentServerSyncHelper private constructor(private val dbHelper: Cowspen
             return instance!!
         }
 
+        @VisibleForTesting
+        fun resetInstance() {
+            instance = null
+            projectIdsToSync.clear()
+        }
+
         fun isNextcloudAccountConfigured(context: Context): Boolean {
             val preferences = PreferenceManager.getDefaultSharedPreferences(context)
             return !preferences.getString(AccountActivity.SETTINGS_URL, AccountActivity.DEFAULT_SETTINGS).isNullOrEmpty() ||

app/src/main/java/net/helcel/cowspent/util/SyncSettings.kt

@@ -0,0 +1,33 @@
+package net.helcel.cowspent.util
+
+import android.content.Context
+import androidx.preference.PreferenceManager
+import net.helcel.cowspent.R
+
+/**
+ * The SyncOnOpen preference: how often opening the app refreshes the account and every project.
+ *
+ * The choices and the default live here rather than in the settings screen so that the screen and
+ * the sync trigger cannot disagree about what is in effect.
+ */
+object SyncSettings {
+
+    /** Steps offered by the slider, in minutes. */
+    val INTERVAL_CHOICES_MINUTES = listOf(1, 10, 60, 1440)
+
+    const val DEFAULT_INTERVAL_MINUTES = 10
+
+    /**
+     * The configured interval in minutes. A stored value that is not one of the offered steps —
+     * from a restored backup, or a build that changed the steps — falls back to the default
+     * rather than being displayed as the first step while a different value drives the sync.
+     */
+    fun intervalMinutes(context: Context): Int {
+        val prefs = PreferenceManager.getDefaultSharedPreferences(context)
+        val stored = prefs.getInt(
+            context.getString(R.string.pref_key_auto_sync_on_open),
+            DEFAULT_INTERVAL_MINUTES
+        )
+        return if (stored in INTERVAL_CHOICES_MINUTES) stored else DEFAULT_INTERVAL_MINUTES
+    }
+}

app/src/main/java/net/helcel/cowspent/util/VersatileProjectSyncClient.kt

@@ -1528,5 +1528,8 @@ class VersatileProjectSyncClient(
         const val METHOD_POST = "POST"
         const val METHOD_PUT = "PUT"
         const val METHOD_DELETE = "DELETE"
+
+        const val REMOTE_ARCHIVED_TS_NOW = 0L
+        const val REMOTE_ARCHIVED_TS_UNSET = -1L
     }
 }

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

@@ -142,6 +142,12 @@
     <string name="settings_beta_features_summary">Enable experimental features. Use at your own risk.</string>
     <string name="settings_fill_new_bill_from_last">Auto-fill from last bill</string>
     <string name="settings_fill_new_bill_from_last_summary">Pre-fill payer, category, mode and owers from the last bill created in the project.</string>
+    <string name="settings_auto_sync_on_open">Sync interval</string>
+    <string name="settings_auto_sync_on_open_summary">How often to refresh the account and all projects when opening the app.</string>
+    <string name="pref_value_sync_1m">1 minute</string>
+    <string name="pref_value_sync_10m">10 minutes</string>
+    <string name="pref_value_sync_1h">1 hour</string>
+    <string name="pref_value_sync_1d">1 day</string>
     <string name="settings_url_warn_http">WARNING: "http" is unsafe. Use "https".</string>
     <string name="settings_colorpicker_title">Choose Color</string>
 
@@ -163,6 +169,8 @@
     <string name="pref_key_offline_mode" translatable="false">offlineMode</string>
     <string name="pref_key_show_archived" translatable="false">showArchived</string>
     <string name="pref_key_beta_features" translatable="false">betaFeatures</string>
+    <string name="pref_key_auto_sync_on_open" translatable="false">autoSyncOnOpen</string>
+    <string name="pref_key_last_account_sync_timestamp" translatable="false">lastAccountSyncTimestamp</string>
     <string name="pref_key_fill_new_bill_from_last" translatable="false">fillNewBillFromLast</string>
     <string name="pref_value_night_mode_no" translatable="false">1</string>
     <string name="pref_value_night_mode_yes" translatable="false">2</string>