feat(write): event delete + WRITE_CALENDAR foundation (v1.1)

First slice of milestone 2 (write support), per the new plan in
docs/superpowers/plans/2026-06-11-03-write-support.md:

- Delete from the event detail screen with confirmation; recurring events
  choose "only this event" (cancelled exception via CONTENT_EXCEPTION_URI,
  series survives) or "all events in the series" (Events-row delete)
- WRITE_CALENDAR in the manifest; onboarding requests read+write in one
  system dialog but only read gates the app — declining write keeps it
  usable read-only. v1.0 installs get a contextual write request on their
  first delete
- CALENDAR_ACCESS_LEVEL is read into CalendarSource.canModifyContents;
  read-only calendars (WebCal, birthdays, …) show no write actions. The
  no-op placeholder Edit button is removed until edit ships (v1.3)
- Onboarding copy drops the now-false "read-only" claim (DE+EN)
- Tests: repository delete delegation/error propagation, access-level
  mapping; FakeCalendarDataSource grows write ops

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/src/main/AndroidManifest.xml

@@ -3,6 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <uses-permission android:name="android.permission.READ_CALENDAR" />
+    <uses-permission android:name="android.permission.WRITE_CALENDAR" />
 
     <application
         android:name=".CalendulaApp"

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

@@ -2,6 +2,7 @@ package de.jeanlucmakiola.calendula.data.calendar
 
 import android.content.ContentResolver
 import android.content.ContentUris
+import android.content.ContentValues
 import android.content.Context
 import android.database.ContentObserver
 import android.database.Cursor
@@ -29,6 +30,16 @@ interface CalendarDataSource {
     fun calendars(): List<CalendarSource>
     fun instances(beginMillis: Long, endMillis: Long): List<EventInstance>
     fun eventDetail(eventId: Long): EventDetail?
+
+    /** Delete the whole event (for recurring events: the entire series). */
+    fun deleteEvent(eventId: Long)
+
+    /**
+     * Cancel a single occurrence of a recurring event by inserting a
+     * cancelled exception at [beginMillis] (the occurrence's `Instances.BEGIN`).
+     */
+    fun deleteOccurrence(eventId: Long, beginMillis: Long)
+
     fun registerChangeListener(listener: () -> Unit)
     fun unregisterChangeListener(listener: () -> Unit)
 }
@@ -74,6 +85,28 @@ class AndroidCalendarDataSource @Inject constructor(
         }
     }
 
+    override fun deleteEvent(eventId: Long) {
+        val deleted = resolver.delete(
+            ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
+            null, null,
+        )
+        if (deleted == 0) throw WriteFailedException("delete event id=$eventId")
+    }
+
+    override fun deleteOccurrence(eventId: Long, beginMillis: Long) {
+        // A cancelled exception row hides exactly this occurrence; the sync
+        // adapter turns it into an EXDATE/cancelled VEVENT upstream.
+        val values = ContentValues().apply {
+            put(CalendarContract.Events.ORIGINAL_INSTANCE_TIME, beginMillis)
+            put(CalendarContract.Events.STATUS, CalendarContract.Events.STATUS_CANCELED)
+        }
+        val uri = ContentUris.withAppendedId(
+            CalendarContract.Events.CONTENT_EXCEPTION_URI, eventId,
+        )
+        resolver.insert(uri, values)
+            ?: throw WriteFailedException("cancel occurrence event id=$eventId begin=$beginMillis")
+    }
+
     override fun registerChangeListener(listener: () -> Unit) {
         val obs = object : ContentObserver(Handler(Looper.getMainLooper())) {
             override fun onChange(selfChange: Boolean) {

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

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import android.provider.CalendarContract
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 
 internal fun ColumnReader.toCalendarSource(): CalendarSource = CalendarSource(
@@ -10,4 +11,6 @@ internal fun ColumnReader.toCalendarSource(): CalendarSource = CalendarSource(
     accountType = getString(CalendarProjection.IDX_ACCOUNT_TYPE).orEmpty(),
     color = getInt(CalendarProjection.IDX_COLOR),
     isVisibleInSystem = getInt(CalendarProjection.IDX_VISIBLE) != 0,
+    canModifyContents = getInt(CalendarProjection.IDX_ACCESS_LEVEL) >=
+        CalendarContract.Calendars.CAL_ACCESS_CONTRIBUTOR,
 )

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

@@ -10,7 +10,17 @@ interface CalendarRepository {
     fun calendars(): Flow<List<CalendarSource>>
     fun instances(range: ClosedRange<Instant>): Flow<List<EventInstance>>
     suspend fun eventDetail(eventId: Long): EventDetail
+
+    /** Delete the whole event (for recurring events: the entire series). */
+    suspend fun deleteEvent(eventId: Long)
+
+    /** Cancel a single occurrence of a recurring event at its `Instances.BEGIN` time. */
+    suspend fun deleteOccurrence(eventId: Long, beginMillis: Long)
 }
 
 class NoSuchEventException(eventId: Long) :
     NoSuchElementException("No event with id=$eventId")
+
+/** A ContentResolver write affected no rows or returned no URI. */
+class WriteFailedException(operation: String) :
+    RuntimeException("Calendar write failed: $operation")

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

@@ -68,6 +68,14 @@ class CalendarRepositoryImpl @Inject constructor(
     override suspend fun eventDetail(eventId: Long): EventDetail = withContext(io) {
         dataSource.eventDetail(eventId) ?: throw NoSuchEventException(eventId)
     }
+
+    override suspend fun deleteEvent(eventId: Long) = withContext(io) {
+        dataSource.deleteEvent(eventId)
+    }
+
+    override suspend fun deleteOccurrence(eventId: Long, beginMillis: Long) = withContext(io) {
+        dataSource.deleteOccurrence(eventId, beginMillis)
+    }
 }
 
 private fun <T> Flow<Unit>.reQuery(block: suspend () -> T): Flow<T> = flow {

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

@@ -10,6 +10,7 @@ internal object CalendarProjection {
         CalendarContract.Calendars.ACCOUNT_TYPE,
         CalendarContract.Calendars.CALENDAR_COLOR,
         CalendarContract.Calendars.VISIBLE,
+        CalendarContract.Calendars.CALENDAR_ACCESS_LEVEL,
     )
 
     const val IDX_ID = 0
@@ -18,6 +19,7 @@ internal object CalendarProjection {
     const val IDX_ACCOUNT_TYPE = 3
     const val IDX_COLOR = 4
     const val IDX_VISIBLE = 5
+    const val IDX_ACCESS_LEVEL = 6
 }
 
 internal object InstanceProjection {

app/src/main/java/de/jeanlucmakiola/calendula/domain/Models.kt

@@ -9,6 +9,12 @@ data class CalendarSource(
     val accountType: String,
     val color: Int,
     val isVisibleInSystem: Boolean,
+    /**
+     * Whether events in this calendar can be created/edited/deleted
+     * (`Calendars.CALENDAR_ACCESS_LEVEL` >= contributor). False for WebCal
+     * subscriptions, birthday calendars and other read-only sources.
+     */
+    val canModifyContents: Boolean = false,
 )
 
 data class EventInstance(

app/src/main/java/de/jeanlucmakiola/calendula/ui/detail/EventDetailScreen.kt

@@ -1,11 +1,15 @@
 package de.jeanlucmakiola.calendula.ui.detail
 
+import android.Manifest
 import android.content.ActivityNotFoundException
 import android.content.Context
 import android.content.Intent
+import android.content.pm.PackageManager
 import android.icu.text.ListFormatter
 import android.net.Uri
 import androidx.activity.compose.BackHandler
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.isSystemInDarkTheme
@@ -24,6 +28,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.selection.selectable
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
@@ -31,31 +36,40 @@ import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.automirrored.filled.Notes
 import androidx.compose.material.icons.filled.CalendarMonth
 import androidx.compose.material.icons.filled.Delete
-import androidx.compose.material.icons.filled.Edit
 import androidx.compose.material.icons.filled.Notifications
 import androidx.compose.material.icons.filled.People
 import androidx.compose.material.icons.filled.Place
 import androidx.compose.material.icons.filled.Public
 import androidx.compose.material.icons.filled.Repeat
 import androidx.compose.material.icons.filled.Schedule
+import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.RadioButton
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+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.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.semantics.Role
+import androidx.core.content.ContextCompat
 import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.AnnotatedString
@@ -94,10 +108,10 @@ import kotlin.time.Duration.Companion.seconds
 import kotlin.time.Instant
 
 /**
- * Read-only full-screen event detail (spec S4, realised as a navigation
- * destination rather than a bottom sheet — MD3 list→detail pattern). Back
- * gesture and the top-bar arrow both return to the calendar. The only action is
- * tapping the location to open a maps intent.
+ * Full-screen event detail (spec S4, realised as a navigation destination
+ * rather than a bottom sheet — MD3 list→detail pattern). Back gesture and the
+ * top-bar arrow both return to the calendar. Events in writable calendars can
+ * be deleted from here (v1.1); edit follows in v1.3.
  */
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -112,10 +126,55 @@ fun EventDetailScreen(
         viewModel.open(eventId, beginMillis, endMillis)
     }
     val state by viewModel.state.collectAsStateWithLifecycle()
+    val deleteState by viewModel.deleteState.collectAsStateWithLifecycle()
 
     BackHandler(onBack = onBack)
 
+    val context = LocalContext.current
+    val snackbarHostState = remember { SnackbarHostState() }
+    var showDeleteDialog by rememberSaveable { mutableStateOf(false) }
+
+    // v1.0 installs only hold READ_CALENDAR; the first write asks for the
+    // upgrade in place. Granting continues straight into the confirm dialog.
+    val writePermissionLauncher = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.RequestPermission(),
+    ) { granted ->
+        if (granted) showDeleteDialog = true
+    }
+    val onDeleteClick = {
+        val granted = ContextCompat.checkSelfPermission(
+            context,
+            Manifest.permission.WRITE_CALENDAR,
+        ) == PackageManager.PERMISSION_GRANTED
+        if (granted) {
+            showDeleteDialog = true
+        } else {
+            writePermissionLauncher.launch(Manifest.permission.WRITE_CALENDAR)
+        }
+    }
+
+    val deleteFailedMessage = stringResource(R.string.event_delete_failed)
+    val writeDeniedMessage = stringResource(R.string.event_delete_write_denied)
+    LaunchedEffect(deleteState) {
+        when (deleteState) {
+            DeleteUiState.Deleted -> {
+                viewModel.consumeDeleteResult()
+                onBack()
+            }
+            DeleteUiState.Failed -> {
+                viewModel.consumeDeleteResult()
+                snackbarHostState.showSnackbar(deleteFailedMessage)
+            }
+            DeleteUiState.NeedsPermission -> {
+                viewModel.consumeDeleteResult()
+                snackbarHostState.showSnackbar(writeDeniedMessage)
+            }
+            DeleteUiState.Idle, DeleteUiState.Deleting -> Unit
+        }
+    }
+
     Scaffold(
+        snackbarHost = { SnackbarHost(snackbarHostState) },
         topBar = {
             TopAppBar(
                 title = {},
@@ -128,17 +187,19 @@ fun EventDetailScreen(
                     }
                 },
                 actions = {
-                    IconButton(onClick = { /* TODO: edit event (V2) */ }) {
-                        Icon(
-                            imageVector = Icons.Default.Edit,
-                            contentDescription = stringResource(R.string.event_detail_edit),
-                        )
-                    }
-                    IconButton(onClick = { /* TODO: delete event (V2) */ }) {
-                        Icon(
-                            imageVector = Icons.Default.Delete,
-                            contentDescription = stringResource(R.string.event_detail_delete),
-                        )
+                    // Only writable calendars get actions — WebCal subscriptions,
+                    // birthday calendars etc. are read-only at the provider level.
+                    val s = state
+                    if (s is EventDetailUiState.Success && s.canModify) {
+                        IconButton(
+                            onClick = onDeleteClick,
+                            enabled = deleteState != DeleteUiState.Deleting,
+                        ) {
+                            Icon(
+                                imageVector = Icons.Default.Delete,
+                                contentDescription = stringResource(R.string.event_detail_delete),
+                            )
+                        }
                     }
                 },
                 colors = TopAppBarDefaults.topAppBarColors(
@@ -159,6 +220,88 @@ fun EventDetailScreen(
             is EventDetailUiState.Success -> EventDetailContent(s, contentModifier)
         }
     }
+
+    val loaded = state
+    if (showDeleteDialog && loaded is EventDetailUiState.Success) {
+        DeleteEventDialog(
+            isRecurring = !loaded.detail.rrule.isNullOrBlank(),
+            onConfirm = { wholeSeries ->
+                showDeleteDialog = false
+                viewModel.delete(wholeSeries)
+            },
+            onDismiss = { showDeleteDialog = false },
+        )
+    }
+}
+
+/**
+ * Delete confirmation. Recurring events choose between cancelling just the
+ * tapped occurrence (default) and removing the whole series.
+ */
+@Composable
+private fun DeleteEventDialog(
+    isRecurring: Boolean,
+    onConfirm: (wholeSeries: Boolean) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    var wholeSeries by rememberSaveable { mutableStateOf(false) }
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = {
+            Text(
+                stringResource(
+                    if (isRecurring) R.string.event_delete_recurring_title
+                    else R.string.event_delete_title,
+                ),
+            )
+        },
+        text = {
+            if (isRecurring) {
+                Column {
+                    DeleteChoiceRow(
+                        selected = !wholeSeries,
+                        label = stringResource(R.string.event_delete_option_occurrence),
+                        onSelect = { wholeSeries = false },
+                    )
+                    DeleteChoiceRow(
+                        selected = wholeSeries,
+                        label = stringResource(R.string.event_delete_option_series),
+                        onSelect = { wholeSeries = true },
+                    )
+                }
+            } else {
+                Text(stringResource(R.string.event_delete_body))
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = { onConfirm(if (isRecurring) wholeSeries else true) }) {
+                Text(
+                    text = stringResource(R.string.event_detail_delete),
+                    color = MaterialTheme.colorScheme.error,
+                )
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text(stringResource(R.string.dialog_cancel))
+            }
+        },
+    )
+}
+
+@Composable
+private fun DeleteChoiceRow(selected: Boolean, label: String, onSelect: () -> Unit) {
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .selectable(selected = selected, role = Role.RadioButton, onClick = onSelect)
+            .padding(vertical = 8.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        RadioButton(selected = selected, onClick = null)
+        Spacer(Modifier.width(8.dp))
+        Text(label, style = MaterialTheme.typography.bodyLarge)
+    }
 }
 
 @Composable

app/src/main/java/de/jeanlucmakiola/calendula/ui/detail/EventDetailUiState.kt

@@ -4,7 +4,7 @@ import de.jeanlucmakiola.calendula.domain.EventDetail
 import de.jeanlucmakiola.calendula.domain.FailureReason
 
 /**
- * UI state for the event-detail bottom sheet (spec S4). Read-only in V1.
+ * UI state for the event-detail screen (spec S4).
  */
 sealed interface EventDetailUiState {
     data object Loading : EventDetailUiState
@@ -13,5 +13,20 @@ sealed interface EventDetailUiState {
         val detail: EventDetail,
         /** Display name of the owning calendar, null if it can't be resolved. */
         val calendarName: String?,
+        /** Whether the owning calendar allows modifying events (shows edit/delete). */
+        val canModify: Boolean = false,
     ) : EventDetailUiState
 }
+
+/**
+ * One-shot state of a delete request, separate from the screen state so a
+ * failed delete leaves the loaded detail visible.
+ */
+sealed interface DeleteUiState {
+    data object Idle : DeleteUiState
+    data object Deleting : DeleteUiState
+    data object Deleted : DeleteUiState
+    /** WRITE_CALENDAR was revoked between the tap and the provider call. */
+    data object NeedsPermission : DeleteUiState
+    data object Failed : DeleteUiState
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/detail/EventDetailViewModel.kt

@@ -12,6 +12,7 @@ import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flatMapLatest
@@ -19,6 +20,7 @@ import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
 import kotlin.coroutines.cancellation.CancellationException
 import kotlin.time.Instant
 import javax.inject.Inject
@@ -38,6 +40,9 @@ class EventDetailViewModel @Inject constructor(
     // Bumped by retry() to re-run the load for the same target.
     private val _reload = MutableStateFlow(0)
 
+    private val _deleteState = MutableStateFlow<DeleteUiState>(DeleteUiState.Idle)
+    val deleteState: StateFlow<DeleteUiState> = _deleteState.asStateFlow()
+
     val state: StateFlow<EventDetailUiState> =
         combine(_target, _reload) { target, _ -> target }
             .flatMapLatest { target ->
@@ -72,6 +77,38 @@ class EventDetailViewModel @Inject constructor(
         _reload.value += 1
     }
 
+    /**
+     * Delete the open event. [wholeSeries] is meaningful only for recurring
+     * events: false cancels just the tapped occurrence. Result lands in
+     * [deleteState]; the screen consumes it via [consumeDeleteResult].
+     */
+    fun delete(wholeSeries: Boolean) {
+        val target = _target.value ?: return
+        if (_deleteState.value == DeleteUiState.Deleting) return
+        viewModelScope.launch {
+            _deleteState.value = DeleteUiState.Deleting
+            _deleteState.value = try {
+                if (wholeSeries) {
+                    repository.deleteEvent(target.eventId)
+                } else {
+                    repository.deleteOccurrence(target.eventId, target.beginMillis)
+                }
+                DeleteUiState.Deleted
+            } catch (e: CancellationException) {
+                throw e
+            } catch (e: SecurityException) {
+                DeleteUiState.NeedsPermission
+            } catch (e: Exception) {
+                DeleteUiState.Failed
+            }
+        }
+    }
+
+    /** Reset [deleteState] after the screen handled a terminal result. */
+    fun consumeDeleteResult() {
+        _deleteState.value = DeleteUiState.Idle
+    }
+
     private suspend fun loadDetail(target: Target): EventDetailUiState = try {
         val detail = repository.eventDetail(target.eventId)
         // The Events row holds the series start; replace it with this
@@ -82,10 +119,13 @@ class EventDetailViewModel @Inject constructor(
                 end = Instant.fromEpochMilliseconds(target.endMillis),
             ),
         )
-        val calendarName = repository.calendars().first()
+        val calendar = repository.calendars().first()
             .firstOrNull { it.id == corrected.instance.calendarId }
-            ?.displayName
-        EventDetailUiState.Success(corrected, calendarName)
+        EventDetailUiState.Success(
+            detail = corrected,
+            calendarName = calendar?.displayName,
+            canModify = calendar?.canModifyContents == true,
+        )
     } catch (e: CancellationException) {
         throw e
     } catch (e: NoSuchEventException) {

app/src/main/java/de/jeanlucmakiola/calendula/ui/permission/PermissionScreen.kt

@@ -56,6 +56,11 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.compose.foundation.Image
 import de.jeanlucmakiola.calendula.R
 
+private val CALENDAR_PERMISSIONS = arrayOf(
+    Manifest.permission.READ_CALENDAR,
+    Manifest.permission.WRITE_CALENDAR,
+)
+
 // MD3 8dp spacing scale, scoped to this screen.
 private object Space {
     val xs = 8.dp
@@ -73,10 +78,17 @@ fun PermissionScreen(
 ) {
     val state by viewModel.state.collectAsStateWithLifecycle()
 
+    // READ and WRITE are requested together (one system dialog — same
+    // permission group), but only READ gates the app: declining write keeps
+    // Calendula usable read-only.
     val launcher = rememberLauncherForActivityResult(
-        contract = ActivityResultContracts.RequestPermission(),
-    ) { granted ->
-        if (granted) viewModel.onGranted() else viewModel.onDenied()
+        contract = ActivityResultContracts.RequestMultiplePermissions(),
+    ) { results ->
+        if (results[Manifest.permission.READ_CALENDAR] == true) {
+            viewModel.onGranted()
+        } else {
+            viewModel.onDenied()
+        }
     }
 
     LaunchedEffect(state) {
@@ -85,13 +97,13 @@ fun PermissionScreen(
 
     when (state) {
         is PermissionUiState.Rationale -> RationaleContent(
-            onRequest = { launcher.launch(Manifest.permission.READ_CALENDAR) },
+            onRequest = { launcher.launch(CALENDAR_PERMISSIONS) },
             modifier = modifier,
         )
         is PermissionUiState.Denied -> DeniedContent(
             onRetry = {
                 viewModel.onRetry()
-                launcher.launch(Manifest.permission.READ_CALENDAR)
+                launcher.launch(CALENDAR_PERMISSIONS)
             },
             modifier = modifier,
         )

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

@@ -13,7 +13,7 @@
 
     <!-- Permission-Flow (F1) -->
     <string name="permission_rationale_title">Alle Termine, schön im Blick</string>
-    <string name="permission_rationale_body">Calendula braucht Lesezugriff auf deinen Kalender, um deine Termine zu zeigen. Mehr verlangt die App nie.</string>
+    <string name="permission_rationale_body">Calendula braucht Zugriff auf deinen Kalender, um deine Termine zu zeigen und zu verwalten. Mehr verlangt die App nie.</string>
     <string name="permission_request_button">Kalender-Zugriff erlauben</string>
     <string name="permission_denied_title">Kalender-Zugriff abgelehnt</string>
     <string name="permission_denied_body">Ohne Kalender-Zugriff kann Calendula keine Termine anzeigen. Du kannst den Zugriff in den System-Einstellungen wieder erlauben.</string>
@@ -25,7 +25,7 @@
     <string name="permission_benefit_sync_body">Google, CalDAV, lokal — alles, was synchronisiert ist, erscheint automatisch.</string>
     <string name="permission_benefit_privacy_title">Kein Tracking, niemals</string>
     <string name="permission_benefit_privacy_body">Keine Telemetrie, keine Analyse, keine Werbung.</string>
-    <string name="permission_privacy_footnote">Nur Lesezugriff · keine Internet-Berechtigung</string>
+    <string name="permission_privacy_footnote">Bleibt auf deinem Gerät · keine Internet-Berechtigung</string>
 
     <!-- Monatsansicht (S1) -->
     <string name="month_prev">Vorheriger Monat</string>
@@ -45,8 +45,15 @@
 
     <!-- Event-Detail-Screen (S4) -->
     <string name="event_detail_back">Zurück</string>
-    <string name="event_detail_edit">Bearbeiten</string>
     <string name="event_detail_delete">Löschen</string>
+    <string name="event_delete_title">Termin löschen?</string>
+    <string name="event_delete_body">Der Termin wird aus deinem Kalender und von allen synchronisierten Geräten entfernt.</string>
+    <string name="event_delete_recurring_title">Wiederkehrenden Termin löschen</string>
+    <string name="event_delete_option_occurrence">Nur dieser Termin</string>
+    <string name="event_delete_option_series">Alle Termine der Serie</string>
+    <string name="event_delete_failed">Termin konnte nicht gelöscht werden</string>
+    <string name="event_delete_write_denied">Calendula braucht Schreibzugriff, um Termine zu löschen</string>
+    <string name="dialog_cancel">Abbrechen</string>
     <string name="event_detail_all_day">Ganztägig</string>
     <string name="event_detail_calendar">Kalender</string>
     <string name="event_detail_calendar_unknown">Unbekannter Kalender</string>

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

@@ -14,7 +14,7 @@
 
     <!-- Permission flow (F1) -->
     <string name="permission_rationale_title">See all your events, beautifully</string>
-    <string name="permission_rationale_body">Calendula needs to read your calendar to show your events. That\'s the only thing it ever asks for.</string>
+    <string name="permission_rationale_body">Calendula needs access to your calendar to show and manage your events. That\'s the only thing it ever asks for.</string>
     <string name="permission_request_button">Grant calendar access</string>
     <string name="permission_denied_title">Calendar access denied</string>
     <string name="permission_denied_body">Calendula cannot show events without calendar access. You can grant it again in the system settings.</string>
@@ -26,7 +26,7 @@
     <string name="permission_benefit_sync_body">Google, CalDAV, local — anything synced to the device just appears.</string>
     <string name="permission_benefit_privacy_title">No tracking, ever</string>
     <string name="permission_benefit_privacy_body">Zero telemetry, zero analytics, no ads.</string>
-    <string name="permission_privacy_footnote">Read-only · no internet permission</string>
+    <string name="permission_privacy_footnote">Stays on your device · no internet permission</string>
 
     <!-- Month view (S1) -->
     <string name="month_prev">Previous month</string>
@@ -46,8 +46,15 @@
 
     <!-- Event detail screen (S4) -->
     <string name="event_detail_back">Back</string>
-    <string name="event_detail_edit">Edit</string>
     <string name="event_detail_delete">Delete</string>
+    <string name="event_delete_title">Delete event?</string>
+    <string name="event_delete_body">The event is removed from your calendar and from every device it syncs to.</string>
+    <string name="event_delete_recurring_title">Delete recurring event</string>
+    <string name="event_delete_option_occurrence">Only this event</string>
+    <string name="event_delete_option_series">All events in the series</string>
+    <string name="event_delete_failed">Couldn\'t delete the event</string>
+    <string name="event_delete_write_denied">Calendula needs write access to delete events</string>
+    <string name="dialog_cancel">Cancel</string>
     <string name="event_detail_all_day">All day</string>
     <string name="event_detail_calendar">Calendar</string>
     <string name="event_detail_calendar_unknown">Unknown calendar</string>

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

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import android.provider.CalendarContract
 import com.google.common.truth.Truth.assertThat
 import org.junit.jupiter.api.Test
 
@@ -12,6 +13,7 @@ class CalendarMapperTest {
         accountType: String? = "LOCAL",
         color: Int = 0,
         visible: Int = 1,
+        accessLevel: Int = CalendarContract.Calendars.CAL_ACCESS_OWNER,
     ): MapColumnReader = MapColumnReader(
         CalendarProjection.IDX_ID to id,
         CalendarProjection.IDX_DISPLAY_NAME to displayName,
@@ -19,6 +21,7 @@ class CalendarMapperTest {
         CalendarProjection.IDX_ACCOUNT_TYPE to accountType,
         CalendarProjection.IDX_COLOR to color,
         CalendarProjection.IDX_VISIBLE to visible,
+        CalendarProjection.IDX_ACCESS_LEVEL to accessLevel,
     )
 
     @Test
@@ -39,6 +42,7 @@ class CalendarMapperTest {
                 accountType = "com.google",
                 color = 0xFF112233.toInt(),
                 isVisibleInSystem = true,
+                canModifyContents = true,
             )
         )
     }
@@ -65,4 +69,25 @@ class CalendarMapperTest {
         assertThat(src.accountName).isEqualTo("")
         assertThat(src.accountType).isEqualTo("")
     }
+
+    @Test
+    fun `contributor access and above can modify contents`() {
+        val contributor = reader(accessLevel = CalendarContract.Calendars.CAL_ACCESS_CONTRIBUTOR)
+        val owner = reader(accessLevel = CalendarContract.Calendars.CAL_ACCESS_OWNER)
+        assertThat(contributor.toCalendarSource().canModifyContents).isTrue()
+        assertThat(owner.toCalendarSource().canModifyContents).isTrue()
+    }
+
+    @Test
+    fun `read access cannot modify contents`() {
+        val src = reader(accessLevel = CalendarContract.Calendars.CAL_ACCESS_READ)
+        assertThat(src.toCalendarSource().canModifyContents).isFalse()
+    }
+
+    @Test
+    fun `missing access level defaults to read-only`() {
+        // WebCal subscriptions on some providers report level 0 (CAL_ACCESS_NONE).
+        val src = reader(accessLevel = CalendarContract.Calendars.CAL_ACCESS_NONE)
+        assertThat(src.toCalendarSource().canModifyContents).isFalse()
+    }
 }

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

@@ -157,6 +157,43 @@ class CalendarRepositoryImplTest {
         }
     }
 
+    @Test
+    fun `deleteEvent delegates to the data source`(@TempDir tempDir: Path) = runTest {
+        val fake = FakeCalendarDataSource()
+        val repo = CalendarRepositoryImpl(fake, newPrefs(tempDir), Dispatchers.Unconfined)
+
+        repo.deleteEvent(eventId = 42L)
+
+        assertThat(fake.deletedEventIds).containsExactly(42L)
+        assertThat(fake.deletedOccurrences).isEmpty()
+    }
+
+    @Test
+    fun `deleteOccurrence forwards event id and begin time`(@TempDir tempDir: Path) = runTest {
+        val fake = FakeCalendarDataSource()
+        val repo = CalendarRepositoryImpl(fake, newPrefs(tempDir), Dispatchers.Unconfined)
+
+        repo.deleteOccurrence(eventId = 42L, beginMillis = 1_000L)
+
+        assertThat(fake.deletedOccurrences).containsExactly(42L to 1_000L)
+        assertThat(fake.deletedEventIds).isEmpty()
+    }
+
+    @Test
+    fun `deleteEvent propagates write failures`(@TempDir tempDir: Path) = runTest {
+        val fake = FakeCalendarDataSource().apply {
+            writeError = WriteFailedException("delete event id=42")
+        }
+        val repo = CalendarRepositoryImpl(fake, newPrefs(tempDir), Dispatchers.Unconfined)
+
+        try {
+            repo.deleteEvent(eventId = 42L)
+            error("Expected WriteFailedException")
+        } catch (expected: WriteFailedException) {
+            assertThat(expected.message).contains("42")
+        }
+    }
+
     @Test
     fun `eventDetail throws NoSuchEventException when data source returns null`(@TempDir tempDir: Path) = runTest {
         val fake = FakeCalendarDataSource().apply {

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

@@ -13,6 +13,11 @@ internal class FakeCalendarDataSource : CalendarDataSource {
     var calendarsResult: List<CalendarSource> = emptyList()
     var instancesResult: (Long, Long) -> List<EventInstance> = { _, _ -> emptyList() }
     var eventDetailResult: (Long) -> EventDetail? = { null }
+    /** Set to make the next write call throw. */
+    var writeError: Exception? = null
+
+    val deletedEventIds = mutableListOf<Long>()
+    val deletedOccurrences = mutableListOf<Pair<Long, Long>>()
 
     private val listeners = mutableListOf<() -> Unit>()
 
@@ -20,6 +25,16 @@ internal class FakeCalendarDataSource : CalendarDataSource {
     override fun instances(beginMillis: Long, endMillis: Long): List<EventInstance> =
         instancesResult(beginMillis, endMillis)
     override fun eventDetail(eventId: Long): EventDetail? = eventDetailResult(eventId)
+
+    override fun deleteEvent(eventId: Long) {
+        writeError?.let { throw it }
+        deletedEventIds += eventId
+    }
+
+    override fun deleteOccurrence(eventId: Long, beginMillis: Long) {
+        writeError?.let { throw it }
+        deletedOccurrences += eventId to beginMillis
+    }
     override fun registerChangeListener(listener: () -> Unit) {
         listeners += listener
     }