feat(intent): handle ACTION_EDIT and broaden .ics MIME types

Round out the calendar-intent surface toward AOSP/Etar parity — the app
already handled VIEW (date + event), INSERT, and .ics open/share, but was
missing the edit action and the alternate .ics MIME labels.

- ACTION_EDIT on content://com.android.calendar/events/<id> now opens the
  event in the edit form (previously only VIEW → read-only detail existed).
  An assistant, task app, or widget can hand an event to Calendula to edit.
  A bare EDIT URI with no occurrence extras falls back to the event row's
  own DTSTART/DTEND, mirroring the #48 view-event fallback.
- ACTION_EDIT with no event id (AOSP's "edit a new event") maps to the same
  prefilled create form as ACTION_INSERT.
- The .ics VIEW/SEND filters now also accept text/x-vcalendar (vCalendar
  1.0 / .vcs) and application/ics — the alternate labels the same calendar
  data arrives under from some file/mail apps (matches Etar's ImportActivity).

Deliberately excluded: webcal:// / http(s) remote-calendar subscription
(needs INTERNET, which the app doesn't have) and the Google-web-link handler
(Google-specific + network).

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

app/src/main/AndroidManifest.xml

@@ -97,32 +97,58 @@
                 <data android:mimeType="time/epoch" />
             </intent-filter>
 
-            <!-- Open a .ics file (file manager / email attachment / browser). -->
+            <!-- Open a .ics/.vcs file (file manager / email attachment / browser).
+                 The three MIME types cover the common labels the same calendar
+                 data arrives under: iCalendar 2.0 (text/calendar), the older
+                 vCalendar 1.0 / .vcs (text/x-vcalendar), and application/ics some
+                 mail apps emit — Android cross-products the scheme and mimeType
+                 tags, so each MIME is accepted on both schemes (matches Etar). -->
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.BROWSABLE" />
-                <data android:scheme="content" android:mimeType="text/calendar" />
-                <data android:scheme="file" android:mimeType="text/calendar" />
+                <data android:scheme="content" />
+                <data android:scheme="file" />
+                <data android:mimeType="text/calendar" />
+                <data android:mimeType="text/x-vcalendar" />
+                <data android:mimeType="application/ics" />
             </intent-filter>
-            <!-- Receive a .ics shared from another app. -->
+            <!-- Receive a .ics/.vcs shared from another app (same MIME set). -->
             <intent-filter>
                 <action android:name="android.intent.action.SEND" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <data android:mimeType="text/calendar" />
+                <data android:mimeType="text/x-vcalendar" />
+                <data android:mimeType="application/ics" />
             </intent-filter>
 
             <!-- Let another app or widget (e.g. the Todo Agenda widget) launch us
                  to create a new event, the way the AOSP calendar accepts it:
                  ACTION_INSERT on the events dir mime type, carrying the new
                  event's fields as CalendarContract extras
-                 (MainActivity.insertFormOrNull, issue #30). -->
+                 (MainActivity.insertFormOrNull, issue #30). ACTION_EDIT on the
+                 dir mime is AOSP's "edit a new event" — i.e. create — so it maps
+                 to the same prefilled create form. -->
             <intent-filter>
                 <action android:name="android.intent.action.INSERT" />
+                <action android:name="android.intent.action.EDIT" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <data android:mimeType="vnd.android.cursor.dir/event" />
             </intent-filter>
 
+            <!-- Edit an existing event another app/assistant/widget points at:
+                 ACTION_EDIT on content://com.android.calendar/events/<id>, the way
+                 AOSP fires it. Opens the occurrence in the edit form (not the
+                 read-only detail — that's the VIEW filter above). Matched by the
+                 provider's item MIME type, like the VIEW filter. The occurrence's
+                 times ride as EXTRA_EVENT_BEGIN_TIME / EXTRA_EVENT_END_TIME when
+                 supplied (MainActivity.editEventKeyOrNull). -->
+            <intent-filter>
+                <action android:name="android.intent.action.EDIT" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="vnd.android.cursor.item/event" />
+            </intent-filter>
+
             <!-- Open an existing event another app/widget points at (e.g. tapping
                  an event in the Todo Agenda widget): ACTION_VIEW on
                  content://com.android.calendar/events/<id>, the way AOSP fires it.

app/src/main/java/de/jeanlucmakiola/calendula/MainActivity.kt

@@ -70,6 +70,11 @@ class MainActivity : AppCompatActivity() {
     // CalendarHost, which opens it in the create form for review.
     private var requestedInsertForm by mutableStateOf<EventForm?>(null)
 
+    // An external "edit this event" (ACTION_EDIT on content://.../events/<id>):
+    // opens the occurrence in the edit form. Same occurrence-key shape as the
+    // detail channel; consumed once by CalendarHost.
+    private var requestedEditKey by mutableStateOf<LongArray?>(null)
+
     // A captured crash report awaiting the user's decision, surfaced as a dialog
     // over the calendar on the next launch (the single-crash path). A startup
     // crash-loop is handled out of band, before setContent — see below.
@@ -95,6 +100,7 @@ class MainActivity : AppCompatActivity() {
         requestedNav = intent.navRequestOrNull()
         requestedImportUri = intent.importUriOrNull()
         requestedInsertForm = intent.insertFormOrNull()
+        requestedEditKey = intent.editEventKeyOrNull()
         if (CrashReporter.shouldPrompt(this)) pendingCrashReport = CrashReporter.pendingReport(this)
         setContent {
             // One activity-scoped SettingsViewModel drives both the theme here
@@ -145,6 +151,8 @@ class MainActivity : AppCompatActivity() {
                             onImportConsumed = { requestedImportUri = null },
                             requestedInsertForm = requestedInsertForm,
                             onInsertConsumed = { requestedInsertForm = null },
+                            requestedEditKey = requestedEditKey,
+                            onEditKeyConsumed = { requestedEditKey = null },
                         )
                     }
                     // A persistent corner marker so a debug build is never
@@ -183,6 +191,7 @@ class MainActivity : AppCompatActivity() {
         intent.navRequestOrNull()?.let { requestedNav = it }
         intent.importUriOrNull()?.let { requestedImportUri = it }
         intent.insertFormOrNull()?.let { requestedInsertForm = it }
+        intent.editEventKeyOrNull()?.let { requestedEditKey = it }
     }
 
     /**
@@ -203,13 +212,19 @@ class MainActivity : AppCompatActivity() {
     }
 
     /**
-     * A prefilled new-event form from an external `ACTION_INSERT` launch — another
-     * app or widget (e.g. Todo Agenda) asking us to create an event (issue #30).
-     * The new event's fields ride as CalendarContract extras; anything omitted
-     * falls back to the in-app "new event" defaults in [buildInsertEventForm].
+     * A prefilled new-event form from an external launch asking us to create an
+     * event — another app or widget (e.g. Todo Agenda) firing `ACTION_INSERT`
+     * (issue #30), or `ACTION_EDIT` with no concrete event id (AOSP's "edit a new
+     * event", i.e. create). The new event's fields ride as CalendarContract
+     * extras; anything omitted falls back to the in-app "new event" defaults in
+     * [buildInsertEventForm].
      */
     private fun Intent.insertFormOrNull(): EventForm? {
-        if (action != Intent.ACTION_INSERT) return null
+        // ACTION_EDIT on an existing event routes to the edit form instead
+        // ([editEventKeyOrNull]); only an id-less EDIT is a create.
+        val isCreate = action == Intent.ACTION_INSERT ||
+            (action == Intent.ACTION_EDIT && editEventKeyOrNull() == null)
+        if (!isCreate) return null
         return buildInsertEventForm(
             beginMillis = longExtraOrNull(CalendarContract.EXTRA_EVENT_BEGIN_TIME),
             endMillis = longExtraOrNull(CalendarContract.EXTRA_EVENT_END_TIME),
@@ -318,6 +333,31 @@ class MainActivity : AppCompatActivity() {
         )
     }
 
+    /**
+     * The occurrence key for an external "edit this event" — `ACTION_EDIT` on
+     * `content://com.android.calendar/events/<id>`, the way AOSP fires it (e.g.
+     * an assistant, task app, or widget that wants to open the event for editing
+     * rather than viewing). Opens it in the edit form. Reuses the same
+     * occurrence-key channel as reminder/view taps; the caller passes the
+     * occurrence's times as `EXTRA_EVENT_BEGIN_TIME` / `EXTRA_EVENT_END_TIME`
+     * when it has them, otherwise we carry [NO_OCCURRENCE_TIME] and
+     * [EventEditViewModel.openForEdit] falls back to the event row's own
+     * DTSTART/DTEND. An id-less `ACTION_EDIT` is a create instead ([insertFormOrNull]).
+     */
+    private fun Intent.editEventKeyOrNull(): LongArray? {
+        if (action != Intent.ACTION_EDIT) return null
+        val uri = data ?: return null
+        if (uri.host != CALENDAR_PROVIDER_HOST) return null
+        val segments = uri.pathSegments
+        if (segments.firstOrNull() != "events") return null
+        val eventId = segments.getOrNull(1)?.toLongOrNull() ?: return null
+        return longArrayOf(
+            eventId,
+            longExtraOrNull(CalendarContract.EXTRA_EVENT_BEGIN_TIME) ?: NO_OCCURRENCE_TIME,
+            longExtraOrNull(CalendarContract.EXTRA_EVENT_END_TIME) ?: NO_OCCURRENCE_TIME,
+        )
+    }
+
     companion object {
         // The calendar provider's authority/host. A date tap arrives as
         // ACTION_VIEW on content://com.android.calendar/time/<epochMillis>.

app/src/main/java/de/jeanlucmakiola/calendula/ui/CalendarHost.kt

@@ -75,6 +75,8 @@ fun CalendarHost(
     onImportConsumed: () -> Unit = {},
     requestedInsertForm: EventForm? = null,
     onInsertConsumed: () -> Unit = {},
+    requestedEditKey: LongArray? = null,
+    onEditKeyConsumed: () -> Unit = {},
     viewModel: CalendarHostViewModel = hiltViewModel(),
 ) {
     // Wait for the persisted default view before seeding the stack, so the app
@@ -212,6 +214,20 @@ fun CalendarHost(
         importForm = null
     }
 
+    // An external "edit this event" (ACTION_EDIT, e.g. an assistant/task app or
+    // widget) opens the occurrence straight in the edit form. Drop any covering
+    // overlay first — the edit overlay sits below Settings/import in the Box, so
+    // without this it would open hidden underneath them. Same held-key pattern as
+    // a detail-screen "Edit" tap; a saved edit just returns to the calendar.
+    LaunchedEffect(requestedEditKey) {
+        if (requestedEditKey != null) {
+            dismissCoveringOverlays()
+            heldEditKey = requestedEditKey
+            editKey = requestedEditKey
+            onEditKeyConsumed()
+        }
+    }
+
     // A home-screen widget launch asks to open a date (→ day view), open an
     // event's detail, or start a create. Handled once and cleared, mirroring
     // [requestedDetailKey]. Date/event opens root the stack in the widget's own

app/src/main/java/de/jeanlucmakiola/calendula/ui/RootScreen.kt

@@ -37,6 +37,8 @@ fun RootScreen(
     onImportConsumed: () -> Unit = {},
     requestedInsertForm: de.jeanlucmakiola.calendula.domain.EventForm? = null,
     onInsertConsumed: () -> Unit = {},
+    requestedEditKey: LongArray? = null,
+    onEditKeyConsumed: () -> Unit = {},
 ) {
     val context = LocalContext.current
     var hasPermission by remember {
@@ -88,6 +90,8 @@ fun RootScreen(
                         onImportConsumed = onImportConsumed,
                         requestedInsertForm = requestedInsertForm,
                         onInsertConsumed = onInsertConsumed,
+                        requestedEditKey = requestedEditKey,
+                        onEditKeyConsumed = onEditKeyConsumed,
                     )
                     false -> ReminderOnboardingScreen(
                         onFinished = reminderOnboarding::finish,

app/src/main/java/de/jeanlucmakiola/calendula/ui/edit/EventEditViewModel.kt

@@ -21,6 +21,7 @@ import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
 import de.jeanlucmakiola.calendula.domain.populatedFields
 import de.jeanlucmakiola.calendula.domain.problems
 import de.jeanlucmakiola.calendula.domain.toEditSnapshot
+import de.jeanlucmakiola.calendula.ui.detail.EventDetailViewModel.Companion.NO_OCCURRENCE_TIME
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
@@ -396,8 +397,12 @@ class EventEditViewModel @Inject constructor(
 
     /**
      * Load an existing event into the form. [beginMillis]/[endMillis] are the
-     * tapped occurrence's own times, like on the detail screen. No-op while a
-     * form is open, so user edits survive configuration changes.
+     * tapped occurrence's own times, like on the detail screen. An external
+     * "edit this event" (`ACTION_EDIT`) that names no occurrence passes
+     * [NO_OCCURRENCE_TIME]; the row's own DTSTART/DTEND is used then, so the
+     * form loads the event's real times instead of the epoch (mirrors the
+     * detail screen's #48 fallback). No-op while a form is open, so user edits
+     * survive configuration changes.
      */
     fun openForEdit(eventId: Long, beginMillis: Long, endMillis: Long) {
         if (_form.value != null || _editTarget.value != null) return
@@ -411,8 +416,12 @@ class EventEditViewModel @Inject constructor(
                 return@launch
             }
             val zone = TimeZone.currentSystemDefault()
-            val snapshot = detail.toEditSnapshot(beginMillis, endMillis, zone)
-            _editTarget.value = EditTarget(eventId, snapshot, beginMillis, endMillis, zone)
+            val begin = beginMillis.takeUnless { it == NO_OCCURRENCE_TIME }
+                ?: detail.instance.start.toEpochMilliseconds()
+            val end = endMillis.takeUnless { it == NO_OCCURRENCE_TIME }
+                ?: detail.instance.end.toEpochMilliseconds()
+            val snapshot = detail.toEditSnapshot(begin, end, zone)
+            _editTarget.value = EditTarget(eventId, snapshot, begin, end, zone)
             // Sections holding data must show even when not in the defaults.
             _revealed.value = snapshot.form.populatedFields()
             _form.value = snapshot.form