feat(contacts): calendar-wide reminders for special-dates calendars

Managed calendars now treat reminders as a calendar-level setting instead of the
seed-once-per-event model, matching how these homogeneous birthday/anniversary
calendars are actually used.

- New per-type "Reminders" control in the Contact special dates section. Changing
  it persists the per-calendar all-day override (so new events match) AND
  re-applies the set to *all existing events* in that calendar
  (CalendarDataSource.applyManagedCalendarReminders → SpecialDatesSyncEngine
  .applyReminders), encoding each event's all-day offset from its own date.
- Settings → Notifications: the contact-date calendars no longer offer a
  per-calendar override row; they show a link that jumps to the Contact special
  dates section (managedCalendarIds now in SettingsUiState).

Tests cover applyReminders (override persisted + bulk-apply invoked, and None
clears). lint + unit tests + assembleDebug green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarDataSource.kt

@@ -29,6 +29,7 @@ import de.jeanlucmakiola.calendula.domain.ics.IcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.ParsedIcsEvent
 import de.jeanlucmakiola.calendula.domain.rruleTruncatedAt
 import kotlinx.datetime.toJavaLocalDate
+import java.time.Instant
 import java.time.ZoneId
 import java.time.ZoneOffset
 import java.util.UUID
@@ -133,6 +134,19 @@ interface CalendarDataSource {
      */
     fun updateManagedFields(eventId: Long, values: Map<String, Any?>)
 
+    /**
+     * Replace the reminders on **every** event in [calendarId] with [minutes]
+     * (all-day lead times), each encoded from its own date so it fires at
+     * [allDayReminderTimeMinutes]. Used by the special-dates section so a reminder
+     * change applies to existing events too, not just future ones — the managed
+     * calendars treat reminders as a calendar-level setting.
+     */
+    fun applyManagedCalendarReminders(
+        calendarId: Long,
+        allDayReminderTimeMinutes: Int,
+        minutes: List<Int>,
+    )
+
     /**
      * Insert a new event; returns the new `Events._ID`. [allDayReminderTimeMinutes]
      * (minutes from local midnight) is the wall-clock time all-day reminders
@@ -456,6 +470,32 @@ class AndroidCalendarDataSource @Inject constructor(
         if (rows == 0) throw WriteFailedException("update managed event id=$eventId")
     }
 
+    override fun applyManagedCalendarReminders(
+        calendarId: Long,
+        allDayReminderTimeMinutes: Int,
+        minutes: List<Int>,
+    ) {
+        val zone = ZoneId.systemDefault()
+        resolver.query(
+            CalendarContract.Events.CONTENT_URI,
+            arrayOf(CalendarContract.Events._ID, CalendarContract.Events.DTSTART),
+            "${CalendarContract.Events.CALENDAR_ID} = ? AND ${CalendarContract.Events.DELETED} = 0",
+            arrayOf(calendarId.toString()),
+            null,
+        )?.use { c ->
+            while (c.moveToNext()) {
+                val eventId = c.getLong(0)
+                // Managed events are all-day: DTSTART is a UTC midnight.
+                val startDate = Instant.ofEpochMilli(c.getLong(1))
+                    .atZone(ZoneOffset.UTC).toLocalDate()
+                val encoded = minutes
+                    .map { toProviderAllDayMinutes(it, startDate, zone, allDayReminderTimeMinutes) }
+                    .distinct()
+                reconcileReminders(eventId, encoded)
+            }
+        }
+    }
+
     override fun instances(beginMillis: Long, endMillis: Long): List<EventInstance> {
         ensureObserversRegistered()
         val uri = CalendarContract.Instances.CONTENT_URI.buildUpon().apply {

app/src/main/java/de/jeanlucmakiola/calendula/data/contacts/SpecialDatesSyncEngine.kt

@@ -90,6 +90,28 @@ class SpecialDatesSyncEngine @Inject constructor(
         return SpecialDatesSyncResult.Success
     }
 
+    /**
+     * Set the reminder default for a type's managed calendar and apply it to
+     * **all** its existing events too (not just future ones) — for managed
+     * calendars the reminder is a calendar-level setting. Persists the per-calendar
+     * all-day override so new events keep matching. No-op if the calendar for
+     * [type] doesn't exist yet.
+     */
+    suspend fun applyReminders(type: SpecialDateType, override: CalendarReminderOverride) {
+        val calendarId = prefs.specialDatesCalendars.first()[type] ?: return
+        prefs.setCalendarAllDayReminderOverride(calendarId, override)
+        val minutes = when (override) {
+            CalendarReminderOverride.Inherit -> prefs.defaultAllDayReminderMinutes.first()
+            CalendarReminderOverride.None -> emptyList()
+            is CalendarReminderOverride.Minutes -> override.minutes
+        }
+        calendars.applyManagedCalendarReminders(
+            calendarId = calendarId,
+            allDayReminderTimeMinutes = prefs.allDayReminderTimeMinutes.first(),
+            minutes = minutes,
+        )
+    }
+
     /** Delete every managed calendar and forget its id — used when the feature is turned off. */
     suspend fun teardown() {
         calendars.findManagedCalendars().forEach { calendars.deleteCalendar(it.id) }

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsScreen.kt

@@ -37,6 +37,7 @@ import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
 import androidx.compose.material.icons.filled.BugReport
 import androidx.compose.material.icons.filled.Cake
 import androidx.compose.material.icons.filled.CalendarMonth
@@ -180,7 +181,12 @@ fun SettingsScreen(
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
             exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
         ) {
-            NotificationsScreen(state = state, viewModel = viewModel, onBack = { section = null })
+            NotificationsScreen(
+                state = state,
+                viewModel = viewModel,
+                onBack = { section = null },
+                onOpenSpecialDates = { section = SettingsSection.SpecialDates },
+            )
         }
         AnimatedVisibility(
             visible = section == SettingsSection.SpecialDates,
@@ -795,6 +801,7 @@ private fun NotificationsScreen(
     state: SettingsUiState,
     viewModel: SettingsViewModel,
     onBack: () -> Unit,
+    onOpenSpecialDates: () -> Unit,
 ) {
     val context = LocalContext.current
     val launcher = rememberLauncherForActivityResult(
@@ -919,6 +926,25 @@ private fun NotificationsScreen(
                 Column {
                     state.writableCalendars.forEach { calendar ->
                         Spacer(Modifier.height(16.dp))
+                        // A contact special-dates calendar owns its reminders in
+                        // its own section — link there instead of an override.
+                        if (calendar.id in state.managedCalendarIds) {
+                            GroupedRow(
+                                title = calendar.displayName,
+                                summary = stringResource(R.string.settings_calendar_reminders_managed_hint),
+                                position = Position.Alone,
+                                leading = { CalendarColorChip(calendar.color) },
+                                trailing = {
+                                    Icon(
+                                        imageVector = Icons.AutoMirrored.Filled.KeyboardArrowRight,
+                                        contentDescription = null,
+                                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                                    )
+                                },
+                                onClick = onOpenSpecialDates,
+                            )
+                            return@forEach
+                        }
                         val expanded = calendar.id in expandedCalendars
                         // Calendar card; tapping expands it into a grouped list
                         // of three (the card + the timed and all-day rows).
@@ -1074,6 +1100,7 @@ private fun SpecialDatesScreen(
     var confirmDisableAll by remember { mutableStateOf(false) }
     var confirmDisableType by remember { mutableStateOf<SpecialDateType?>(null) }
     var editTemplate by remember { mutableStateOf<SpecialDateType?>(null) }
+    var reminderPickerType by remember { mutableStateOf<SpecialDateType?>(null) }
 
     CollapsingScaffold(
         title = stringResource(R.string.settings_section_special_dates),
@@ -1120,13 +1147,13 @@ private fun SpecialDatesScreen(
         )
 
         if (state.enabled) {
-            Spacer(Modifier.height(24.dp))
+            // Per-type card: the toggle, and while on, its calendar-wide reminder.
-            // Per-type toggles + their title templates.
             SpecialDateType.entries.forEachIndexed { index, type ->
+                Spacer(Modifier.height(if (index == 0) 24.dp else 16.dp))
                 val on = type in state.types
                 GroupedRow(
                     title = stringResource(specialDateTypeLabel(type)),
-                    position = if (index == 0) Position.Top else Position.Middle,
+                    position = if (on) Position.Top else Position.Alone,
                     trailing = {
                         Switch(
                             checked = on,
@@ -1140,11 +1167,21 @@ private fun SpecialDatesScreen(
                         if (on) confirmDisableType = type else viewModel.setSpecialDateTypeEnabled(type, true)
                     },
                 )
+                if (on) {
+                    GroupedRow(
+                        title = stringResource(R.string.settings_special_dates_reminders),
+                        summary = reminderChoiceLabel(specialDatesReminderMinutes(state.reminderChoices[type])),
+                        position = Position.Bottom,
+                        onClick = { reminderPickerType = type },
+                    )
                 }
+            }
+
+            Spacer(Modifier.height(24.dp))
             GroupedRow(
                 title = stringResource(R.string.settings_special_dates_template),
                 summary = state.titleTemplates[SpecialDateType.Birthday].orEmpty(),
-                position = Position.Bottom,
+                position = Position.Alone,
                 onClick = { editTemplate = SpecialDateType.Birthday },
             )
 
@@ -1202,8 +1239,23 @@ private fun SpecialDatesScreen(
             onDismiss = { editTemplate = null },
         )
     }
+    reminderPickerType?.let { type ->
+        ReminderDefaultPicker(
+            title = stringResource(R.string.settings_special_dates_reminders),
+            presets = ALLDAY_REMINDER_PRESETS,
+            selected = state.reminderChoices[type] ?: CalendarReminderOverride.None,
+            // Managed calendars own their reminders outright — no "inherit global".
+            allowInherit = false,
+            onSelect = { viewModel.setSpecialDatesReminders(type, it) },
+            onDismiss = { reminderPickerType = null },
+        )
+    }
 }
 
+/** The lead-time list backing a managed calendar's reminder choice (for the summary label). */
+private fun specialDatesReminderMinutes(choice: CalendarReminderOverride?): List<Int> =
+    (choice as? CalendarReminderOverride.Minutes)?.minutes.orEmpty()
+
 @Composable
 private fun SpecialDatesDisableDialog(
     message: String,

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsUiState.kt

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.ui.settings
 
+import de.jeanlucmakiola.calendula.data.prefs.CalendarReminderOverride
 import de.jeanlucmakiola.calendula.data.prefs.PastEventDisplay
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.data.prefs.ThemeMode
@@ -70,6 +71,12 @@ data class SettingsUiState(
      * colour palette (the colour may then not survive their next sync).
      */
     val allowColorOnUnsupportedCalendars: Boolean = false,
+    /**
+     * Ids of the contact special-dates calendars. Their reminders are owned by
+     * the Contact special dates section, so the per-calendar override list links
+     * out to it instead of offering an override here.
+     */
+    val managedCalendarIds: Set<Long> = emptySet(),
 )
 
 /**
@@ -82,6 +89,8 @@ data class SpecialDatesUiState(
     val enabled: Boolean = false,
     val types: Set<SpecialDateType> = SpecialDateType.entries.toSet(),
     val titleTemplates: Map<SpecialDateType, String> = emptyMap(),
+    /** The reminder choice per type's managed calendar (applied to all its events). */
+    val reminderChoices: Map<SpecialDateType, CalendarReminderOverride> = emptyMap(),
     val showAge: Boolean = true,
     /** True when READ_CONTACTS was revoked after enabling — the mirror is paused. */
     val stalledPermission: Boolean = false,

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsViewModel.kt

@@ -97,8 +97,9 @@ class SettingsViewModel @Inject constructor(
                 prefs.perCalendarReminderOverride,
                 prefs.perCalendarAllDayReminderOverride,
                 writableCalendars,
-            ) { overrides, allDayOverrides, calendars ->
+                prefs.managedCalendarIds,
-                ReminderOverrides(overrides, allDayOverrides, calendars)
+            ) { overrides, allDayOverrides, calendars, managedIds ->
+                ReminderOverrides(overrides, allDayOverrides, calendars, managedIds)
             },
             combine(
                 prefs.defaultView,
@@ -135,6 +136,7 @@ class SettingsViewModel @Inject constructor(
                 perCalendarReminderOverride = overrides.timed,
                 perCalendarAllDayReminderOverride = overrides.allDay,
                 writableCalendars = overrides.calendars,
+                managedCalendarIds = overrides.managedIds,
             )
         }.stateIn(
             scope = viewModelScope,
@@ -160,6 +162,7 @@ class SettingsViewModel @Inject constructor(
         val timed: Map<Long, List<Int>>,
         val allDay: Map<Long, List<Int>>,
         val calendars: List<CalendarSource>,
+        val managedIds: Set<Long>,
     )
 
     private data class ViewSettings(
@@ -179,6 +182,7 @@ class SettingsViewModel @Inject constructor(
 
     /** Contact special-dates sub-page (issue #15); its own flow — the main state is full. */
     val specialDatesState: StateFlow<SpecialDatesUiState> = combine(
+        combine(
             prefs.specialDatesEnabled,
             prefs.specialDatesTypes,
             prefs.specialDatesTitleTemplates,
@@ -198,6 +202,20 @@ class SettingsViewModel @Inject constructor(
                 stalledPermission = status.stalled == SpecialDatesStalledReason.PermissionRevoked,
                 lastRun = status.lastRun,
             )
+        },
+        prefs.specialDatesCalendars,
+        prefs.perCalendarAllDayReminderOverride,
+    ) { base, calendars, allDayOverrides ->
+        base.copy(
+            reminderChoices = calendars.mapValues { (_, calendarId) ->
+                // An override is always seeded on creation; present-empty = None.
+                when (val minutes = allDayOverrides[calendarId]) {
+                    null -> CalendarReminderOverride.Inherit
+                    emptyList<Int>() -> CalendarReminderOverride.None
+                    else -> CalendarReminderOverride.Minutes(minutes)
+                }
+            },
+        )
     }.stateIn(
         scope = viewModelScope,
         started = SharingStarted.WhileSubscribed(5_000L),
@@ -245,6 +263,14 @@ class SettingsViewModel @Inject constructor(
         }
     }
 
+    /**
+     * Set a type's managed-calendar reminder default and apply it to all its
+     * existing events (managed calendars own their reminders calendar-wide).
+     */
+    fun setSpecialDatesReminders(type: SpecialDateType, override: CalendarReminderOverride) {
+        viewModelScope.launch { withContext(io) { specialDatesEngine.applyReminders(type, override) } }
+    }
+
     /** Kick off an immediate reconcile (the "Sync now" action). */
     fun syncSpecialDatesNow() = SpecialDatesScheduler.runNow(appContext)
 

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

@@ -428,13 +428,15 @@
     <string name="settings_special_dates_type_custom">Weitere Tage</string>
     <string name="settings_special_dates_template">Titelformat</string>
     <string name="settings_special_dates_template_hint">Verwende {name} für den Kontakt und {age} für das Alter (ausgeblendet, wenn das Jahr unbekannt ist).</string>
-    <string name="settings_special_dates_template_age_note">Hinweis: {age} ist das Alter zum nächsten Termin beim letzten Sync. Da ein jährlicher Termin nur einen Titel hat, kann es bei weit entfernten Terminen unpassend wirken.</string>
+    <string name="settings_special_dates_template_age_note">Hinweis: Das Alter ist ein einzelner Wert vom letzten Sync — es wird nicht für jedes Jahr aktualisiert. Jeder jährliche Termin zeigt daher dieselbe Zahl, was bei weiter zurück- oder vorausliegenden Terminen falsch sein kann.</string>
+    <string name="settings_special_dates_reminders">Erinnerungen</string>
     <string name="settings_special_dates_show_age">Alter anzeigen</string>
     <string name="settings_special_dates_show_age_hint">{age} in Titeln anzeigen, wenn das Geburtsjahr bekannt ist</string>
     <string name="settings_special_dates_sync_now">Jetzt synchronisieren</string>
     <string name="settings_special_dates_never_synced">Noch nicht synchronisiert</string>
     <string name="settings_special_dates_last_synced">Zuletzt synchronisiert %1$s</string>
-    <string name="settings_special_dates_calendar_hint">Farbe, Sichtbarkeit und Erinnerungen jedes Kalenders legst du in den Kalender-Einstellungen fest.</string>
+    <string name="settings_special_dates_calendar_hint">Farbe und Sichtbarkeit jedes Kalenders legst du in den Kalender-Einstellungen fest.</string>
+    <string name="settings_calendar_reminders_managed_hint">In Besondere Kontakttage festgelegt</string>
     <string name="settings_special_dates_paused_title">Pausiert</string>
     <string name="settings_special_dates_paused_hint">Calendula kann deine Kontakte nicht mehr lesen, daher werden diese Kalender nicht aktualisiert.</string>
     <string name="settings_special_dates_grant">Zugriff erlauben</string>

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

@@ -357,14 +357,16 @@
     <string name="settings_special_dates_type_custom">Other dates</string>
     <string name="settings_special_dates_template">Title format</string>
     <string name="settings_special_dates_template_hint">Use {name} for the contact and {age} for their age (hidden when the year is unknown).</string>
-    <string name="settings_special_dates_template_age_note">Note: {age} is the age at the next date as of the last sync. Because a yearly event has one title, it can look off on occurrences far in the future.</string>
+    <string name="settings_special_dates_template_age_note">Note: the age is a single value set at the last sync — it isn\'t updated for each year, so every yearly occurrence shows the same number and it can be wrong for dates further in the past or future.</string>
+    <string name="settings_special_dates_reminders">Reminders</string>
     <string name="settings_special_dates_show_age">Show age</string>
     <string name="settings_special_dates_show_age_hint">Include {age} in titles when the birth year is known</string>
     <string name="settings_special_dates_sync_now">Sync now</string>
     <string name="settings_special_dates_never_synced">Not synced yet</string>
     <!-- %1$s is a relative time, e.g. "5 minutes ago". -->
     <string name="settings_special_dates_last_synced">Last synced %1$s</string>
-    <string name="settings_special_dates_calendar_hint">Set each calendar\'s colour, visibility and reminders in Calendars settings.</string>
+    <string name="settings_special_dates_calendar_hint">Set each calendar\'s colour and visibility in Calendars settings.</string>
+    <string name="settings_calendar_reminders_managed_hint">Set in Contact special dates</string>
     <string name="settings_special_dates_paused_title">Paused</string>
     <string name="settings_special_dates_paused_hint">Calendula can no longer read your contacts, so these calendars aren\'t updating.</string>
     <string name="settings_special_dates_grant">Grant access</string>

app/src/test/java/de/jeanlucmakiola/calendula/data/calendar/FakeCalendarDataSource.kt

@@ -190,6 +190,18 @@ internal class FakeCalendarDataSource : CalendarDataSource {
         return id
     }
 
+    /** (calendarId, allDayTime, minutes) recorded from applyManagedCalendarReminders. */
+    val appliedManagedReminders = mutableListOf<Triple<Long, Int, List<Int>>>()
+
+    override fun applyManagedCalendarReminders(
+        calendarId: Long,
+        allDayReminderTimeMinutes: Int,
+        minutes: List<Int>,
+    ) {
+        writeError?.let { throw it }
+        appliedManagedReminders += Triple(calendarId, allDayReminderTimeMinutes, minutes)
+    }
+
     override fun updateManagedFields(eventId: Long, values: Map<String, Any?>) {
         writeError?.let { throw it }
         if (values.isEmpty()) return

app/src/test/java/de/jeanlucmakiola/calendula/data/contacts/SpecialDatesSyncEngineTest.kt

@@ -7,6 +7,7 @@ import androidx.datastore.preferences.core.Preferences
 import com.google.common.truth.Truth.assertThat
 import de.jeanlucmakiola.calendula.data.calendar.FakeCalendarDataSource
 import de.jeanlucmakiola.calendula.data.calendar.ManagedEventRow
+import de.jeanlucmakiola.calendula.data.prefs.CalendarReminderOverride
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.contacts.ContactSpecialDate
 import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
@@ -163,6 +164,38 @@ class SpecialDatesSyncEngineTest {
         assertThat(settings.specialDatesCalendars.first()).doesNotContainKey(SpecialDateType.Anniversary)
     }
 
+    @Test
+    fun `applyReminders persists the override and applies it to all events`(@TempDir tempDir: Path) = runTest {
+        val calendars = FakeCalendarDataSource()
+        val contacts = FakeContacts(dates = listOf(birthday("a", "Jane", 5, 14, 1990)))
+        val (engine, settings) = engineWith(tempDir, contacts, calendars)
+        engine.sync(today)
+        val birthdayCal = settings.specialDatesCalendars.first().getValue(SpecialDateType.Birthday)
+
+        engine.applyReminders(SpecialDateType.Birthday, CalendarReminderOverride.Minutes(listOf(0, 1440)))
+
+        // Persisted as the per-calendar all-day override (so new events match)...
+        assertThat(settings.perCalendarAllDayReminderOverride.first()[birthdayCal])
+            .isEqualTo(listOf(0, 1440))
+        // ...and applied to the existing events in that calendar.
+        assertThat(calendars.appliedManagedReminders).contains(
+            Triple(birthdayCal, settings.allDayReminderTimeMinutes.first(), listOf(0, 1440)),
+        )
+    }
+
+    @Test
+    fun `applyReminders with None clears the reminders`(@TempDir tempDir: Path) = runTest {
+        val calendars = FakeCalendarDataSource()
+        val (engine, settings) = engineWith(tempDir, FakeContacts(), calendars)
+        engine.sync(today)
+        val birthdayCal = settings.specialDatesCalendars.first().getValue(SpecialDateType.Birthday)
+
+        engine.applyReminders(SpecialDateType.Birthday, CalendarReminderOverride.None)
+
+        assertThat(settings.perCalendarAllDayReminderOverride.first()[birthdayCal]).isEmpty()
+        assertThat(calendars.appliedManagedReminders.last().third).isEmpty()
+    }
+
     // --- pure diff ---
 
     private fun desired(uid: String, title: String, dt: Long, rrule: String? = "FREQ=YEARLY") =