Make the recurrence window relative to today, and configurable

app/src/main/java/at/techbee/jtx/database/ICalDatabaseDao.kt

@@ -1229,6 +1229,16 @@ interface ICalDatabaseDao {
     suspend fun makeSeriesDirty(uid: String, lastModified: Long = System.currentTimeMillis())
 
 
+    @Query("SELECT * FROM $TABLE_NAME_ICALOBJECT WHERE $COLUMN_RRULE IS NOT NULL AND $COLUMN_RECURID IS NULL AND $COLUMN_DELETED = 0")
+    fun getAllSeriesSync(): List<ICalObject>
+
+    /**
+     * Rebuilds the instances of every series, needed when the recurrence window changes. Instances
+     * are inserted with dirty = false and changed ones are kept, so nothing is uploaded.
+     */
+    @Transaction
+    fun recreateAllRecurring() = getAllSeriesSync().forEach { recreateRecurring(it) }
+
     @Transaction
     fun recreateRecurring(iCalObject: ICalObject) {
 

app/src/main/java/at/techbee/jtx/database/ICalObject.kt

@@ -996,6 +996,14 @@ data class ICalObject(
     private fun buildPeriod(
         start: ZonedDateTime,
         frequency: Frequency
+    ): Period<ZonedDateTime> = when (val window = RecurrenceWindow.current) {
+        is RecurrenceWindow.Legacy -> legacyPeriod(start, frequency)
+        is RecurrenceWindow.AroundToday -> periodAroundToday(start, frequency, window)
+    }
+
+    private fun legacyPeriod(
+        start: ZonedDateTime,
+        frequency: Frequency
     ): Period<ZonedDateTime> {
 
         val from = when (frequency) {
@@ -1021,6 +1029,29 @@ data class ICalObject(
         return Period(from, to)
     }
 
+    private fun periodAroundToday(
+        start: ZonedDateTime,
+        frequency: Frequency,
+        window: RecurrenceWindow.AroundToday
+    ): Period<ZonedDateTime> {
+
+        // A series starting in the future would materialise nothing, and the list hides a series
+        // that has an RRULE and a DTSTART in favour of its instances - so it would vanish.
+        val now = ZonedDateTime.now(start.zone)
+        val reference = if (start.isAfter(now)) start else now
+
+        return when (frequency) {
+            // Three months of a SECONDLY rule is millions of rows wherever the window sits.
+            Frequency.SECONDLY -> Period(reference.minusHours(1), reference.plusHours(1))
+            Frequency.MINUTELY -> Period(reference.minusDays(1), reference.plusDays(1))
+            Frequency.HOURLY   -> Period(reference.minusDays(30), reference.plusDays(30))
+            else -> Period(
+                reference.minusMonths(window.monthsBack),
+                reference.plusMonths(window.monthsAhead)
+            )
+        }
+    }
+
     private fun normalizeRruleForAllDay() {
         if (rrule == null)
             return

app/src/main/java/at/techbee/jtx/database/RecurrenceWindow.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) Techbee e.U.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.techbee.jtx.database
+
+/**
+ * How far around its reference point recurrence instances are materialised.
+ *
+ * [Legacy] centres the window on DTSTART, and since nothing is generated before DTSTART that
+ * reaches forward from the start of the series: for a weekly series older than a year the window
+ * ends before today and no current occurrence is created at all.
+ */
+sealed interface RecurrenceWindow {
+
+    data object Legacy : RecurrenceWindow
+
+    data class AroundToday(val monthsBack: Long, val monthsAhead: Long) : RecurrenceWindow
+
+    companion object {
+        // Read from getInstancesFromRrule(), which is reached from Room DAO methods and from the
+        // sync content provider - neither carries a Context, so passing the value in would thread a
+        // parameter up into the ViewModels.
+        @Volatile
+        var current: RecurrenceWindow = Legacy
+    }
+}

app/src/main/java/at/techbee/jtx/ui/settings/DropdownSetting.kt

@@ -13,6 +13,7 @@ import android.os.Build
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.outlined.Alarm
 import androidx.compose.material.icons.outlined.EditCalendar
+import androidx.compose.material.icons.outlined.EventRepeat
 import androidx.compose.material.icons.outlined.Fingerprint
 import androidx.compose.material.icons.outlined.FontDownload
 import androidx.compose.material.icons.outlined.FormatPaint
@@ -34,6 +35,19 @@ enum class DropdownSetting(
     val options: List<DropdownSettingOption>,
     val default: DropdownSettingOption
 ) {
+    SETTING_RECUR_WINDOW(
+        key = "setting_recur_window",
+        icon = Icons.Outlined.EventRepeat,
+        title = R.string.settings_recur_window,
+        subtitle = R.string.settings_recur_window_sub,
+        options = listOf(
+            DropdownSettingOption.RECUR_WINDOW_LEGACY,
+            DropdownSettingOption.RECUR_WINDOW_1_MONTH,
+            DropdownSettingOption.RECUR_WINDOW_3_MONTHS,
+            DropdownSettingOption.RECUR_WINDOW_1_YEAR
+        ),
+        default = DropdownSettingOption.RECUR_WINDOW_LEGACY
+    ),
     SETTING_THEME(
         key = "settings_theme",
         icon = Icons.Outlined.FormatPaint,

app/src/main/java/at/techbee/jtx/ui/settings/DropdownSettingOption.kt

@@ -17,6 +17,10 @@ enum class DropdownSettingOption(
     val key: String,
     @StringRes val text: Int
 ) {
+    RECUR_WINDOW_LEGACY("recur_window_legacy", R.string.settings_recur_window_legacy),
+    RECUR_WINDOW_1_MONTH("recur_window_1_month", R.string.settings_recur_window_1_month),
+    RECUR_WINDOW_3_MONTHS("recur_window_3_months", R.string.settings_recur_window_3_months),
+    RECUR_WINDOW_1_YEAR("recur_window_1_year", R.string.settings_recur_window_1_year),
     THEME_SYSTEM("system", R.string.settings_select_theme_system),
     THEME_LIGHT("light", R.string.settings_select_theme_light),
     THEME_DARK("dark", R.string.settings_select_theme_dark),

app/src/main/java/at/techbee/jtx/ui/settings/SettingsScreen.kt

@@ -75,6 +75,8 @@ import at.techbee.jtx.ui.settings.DropdownSetting.SETTING_FONT
 import at.techbee.jtx.ui.settings.DropdownSetting.SETTING_MAPS_PROVIDER
 import at.techbee.jtx.ui.settings.DropdownSetting.SETTING_PROGRESS_STEP
 import at.techbee.jtx.ui.settings.DropdownSetting.SETTING_PROTECT_BIOMETRIC
+import at.techbee.jtx.database.ICalDatabase
+import at.techbee.jtx.ui.settings.DropdownSetting.SETTING_RECUR_WINDOW
 import at.techbee.jtx.ui.settings.DropdownSetting.SETTING_THEME
 import at.techbee.jtx.ui.settings.SwitchSetting.SETTING_ACCESSIBILITY_MODE
 import at.techbee.jtx.ui.settings.SwitchSetting.SETTING_AUTO_EXPAND_ATTACHMENTS
@@ -703,6 +705,19 @@ fun SettingsScreen(
                         onToggle = { expandOrCollapse(SettingsScreenSection.ITEM_LIST) },
                         modifier = Modifier.fillMaxWidth()
                     ) {
+                        DropdownSettingElement(
+                            setting = SETTING_RECUR_WINDOW,
+                            selected = settingsStateHolder.settingRecurWindow.value,
+                            onSelectionChanged = { selection ->
+                                settingsStateHolder.settingRecurWindow.value = selection
+                                SETTING_RECUR_WINDOW.saveSetting(selection, settingsStateHolder.prefs)
+                                settingsStateHolder.applyRecurrenceWindow()
+                                // The stored instances were materialised for the previous window.
+                                scope.launch(Dispatchers.IO) {
+                                    ICalDatabase.getInstance(context).iCalDatabaseDao().recreateAllRecurring()
+                                }
+                            }
+                        )
                         SwitchSettingElement(
                             setting = SETTING_AUTO_EXPAND_SUBTASKS,
                             checked = settingsStateHolder.settingAutoExpandSubtasks,

app/src/main/java/at/techbee/jtx/ui/settings/SettingsStateHolder.kt

@@ -14,6 +14,7 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.core.content.edit
 import androidx.preference.PreferenceManager
 import at.techbee.jtx.database.Module
+import at.techbee.jtx.database.RecurrenceWindow
 import at.techbee.jtx.ui.detail.DetailTopAppBarMode
 
 class SettingsStateHolder(val context: Context) {
@@ -57,6 +58,7 @@ class SettingsStateHolder(val context: Context) {
     var settingKeepStatusProgressCompletedInSync = mutableStateOf(SwitchSetting.SETTING_KEEP_STATUS_PROGRESS_COMPLETED_IN_SYNC.getSetting(prefs))
     var settingProtectBiometric = mutableStateOf(DropdownSetting.SETTING_PROTECT_BIOMETRIC.getSetting(prefs))
     var settingDisplayTimezone = mutableStateOf(DropdownSetting.SETTING_DISPLAY_TIMEZONE.getSetting(prefs))
+    var settingRecurWindow = mutableStateOf(DropdownSetting.SETTING_RECUR_WINDOW.getSetting(prefs))
 
     var settingSetDefaultCurrentLocationJournals = mutableStateOf(SwitchSetting.SETTING_JOURNALS_SET_DEFAULT_CURRENT_LOCATION.getSetting(prefs))
     var settingSetDefaultCurrentLocationNotes = mutableStateOf(SwitchSetting.SETTING_NOTES_SET_DEFAULT_CURRENT_LOCATION.getSetting(prefs))
@@ -110,6 +112,21 @@ class SettingsStateHolder(val context: Context) {
             field = newValue
         }
      */
+
+    init {
+        applyRecurrenceWindow()
+    }
+
+    fun applyRecurrenceWindow() {
+        // A month of history keeps a recently missed occurrence visible.
+        RecurrenceWindow.current = when (settingRecurWindow.value) {
+            DropdownSettingOption.RECUR_WINDOW_1_MONTH -> RecurrenceWindow.AroundToday(monthsBack = 1, monthsAhead = 1)
+            DropdownSettingOption.RECUR_WINDOW_3_MONTHS -> RecurrenceWindow.AroundToday(monthsBack = 1, monthsAhead = 3)
+            DropdownSettingOption.RECUR_WINDOW_1_YEAR -> RecurrenceWindow.AroundToday(monthsBack = 1, monthsAhead = 12)
+            else -> RecurrenceWindow.Legacy
+        }
+    }
+
 }
 
 

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

@@ -387,6 +387,12 @@
     <string name="settings_export_error">"An error occurred while exporting settings"</string>
     <string name="more">"More"</string>
     <string name="navigation_drawer_buypro">"Buy Pro"</string>
+    <string name="settings_recur_window">"Occurrences of recurring entries"</string>
+    <string name="settings_recur_window_sub">"Which single occurrences of a series are created. From the start of the series reaches one year ahead for daily and weekly rules, ten years for monthly and a hundred for yearly - so a weekly series that began more than a year ago only gets occurrences from its first year, and none around today."</string>
+    <string name="settings_recur_window_legacy">"From the start of the series"</string>
+    <string name="settings_recur_window_1_month">"Around today (1 month)"</string>
+    <string name="settings_recur_window_3_months">"Around today (3 months)"</string>
+    <string name="settings_recur_window_1_year">"Around today (1 year)"</string>
     <string name="settings_select_theme">"Select theme"</string>
     <string name="settings_select_theme_dark">"Dark"</string>
     <string name="settings_select_theme_light">"Light"</string>