feat: better fail to find event fallback 66 (#163)

* docs: plan

* docs: test

* feat: phase 1 and 2

* feat: draw the rest of the fucking owl lol

* docs: update

Author: williscool

android/app/src/main/java/com/github/quarck/calnotify/calendar/CalendarIntents.kt

@@ -1,6 +1,7 @@
 //
 //   Calendar Notifications Plus
 //   Copyright (C) 2016 Sergey Parshin (s.parshin.sc@gmail.com)
+//   Copyright (C) 2025 William Harris (wharris+cnplus@upscalews.com)
 //
 //   This program is free software; you can redistribute it and/or modify
 //   it under the terms of the GNU General Public License as published by
@@ -22,6 +23,7 @@ package com.github.quarck.calnotify.calendar
 import android.content.ContentUris
 import android.content.Context
 import android.content.Intent
+import android.net.Uri
 import android.provider.CalendarContract
 import com.github.quarck.calnotify.logs.DevLog
 
@@ -69,4 +71,56 @@ object CalendarIntents {
 
     fun viewCalendarEvent(context: Context, eventId: Long)
             = context.startActivity(intentForAction(Intent.ACTION_VIEW, eventId))
+
+    /**
+     * Opens calendar at a specific time (fallback when event not found).
+     * 
+     * Uses the calendar time URI format: content://com.android.calendar/time/{millis}
+     * This opens the calendar app's day/week view centered on the specified time.
+     * 
+     * @param context The context to start the activity from
+     * @param timeMillis The time in milliseconds to open the calendar at
+     * 
+     * @see <a href="https://github.com/williscool/CalendarNotification/issues/66">Issue #66</a>
+     */
+    fun viewCalendarAtTime(context: Context, timeMillis: Long) {
+        val uri = Uri.parse("content://com.android.calendar/time/$timeMillis")
+        val intent = Intent(Intent.ACTION_VIEW).setData(uri)
+        context.startActivity(intent)
+    }
+
+    /**
+     * Attempts to view an event in the calendar, with fallback to time-based view if event not found.
+     * 
+     * This method first checks if the event exists in the system calendar. If found, it opens
+     * the event directly. If not found (e.g., after phone restore, sync issues, or deletion),
+     * it falls back to opening the calendar at the event's scheduled time.
+     * 
+     * @param context The context to start the activity from
+     * @param calendarProvider The calendar provider to check event existence
+     * @param event The event to view
+     * @return true if the event was found and opened directly, false if fallback was used
+     * 
+     * @see <a href="https://github.com/williscool/CalendarNotification/issues/66">Issue #66</a>
+     */
+    fun viewCalendarEventWithFallback(
+        context: Context,
+        calendarProvider: CalendarProviderInterface,
+        event: EventAlertRecord
+    ): Boolean {
+        // Check if event exists in system calendar
+        val calendarEvent = calendarProvider.getEvent(context, event.eventId)
+
+        return if (calendarEvent != null) {
+            // Event exists, open normally
+            viewCalendarEvent(context, event)
+            true
+        } else {
+            // Event not found, fallback to time-based view
+            DevLog.info(LOG_TAG, "Event ${event.eventId} not found in calendar, " +
+                "falling back to time view at ${event.instanceStartTime}")
+            viewCalendarAtTime(context, event.instanceStartTime)
+            false
+        }
+    }
 }

android/app/src/main/java/com/github/quarck/calnotify/ui/ViewEventActivityNoRecents.kt

@@ -1,6 +1,7 @@
 //
 //   Calendar Notifications Plus  
 //   Copyright (C) 2016 Sergey Parshin (s.parshin.sc@gmail.com)
+//   Copyright (C) 2025 William Harris (wharris+cnplus@upscalews.com)
 //
 //   This program is free software; you can redistribute it and/or modify
 //   it under the terms of the GNU General Public License as published by
@@ -102,9 +103,14 @@ class ViewEventById(private val context: Context, internal var eventId: Long) :
     }
 }
 
+/**
+ * Runnable that opens an event in the calendar with fallback if event not found.
+ * Uses CalendarProvider singleton to check event existence.
+ */
 class ViewEventByEvent(private val context: Context, internal var event: EventAlertRecord) : Runnable {
     override fun run() {
-        CalendarIntents.viewCalendarEvent(context, event)
+        // Use fallback method - if event not found, opens calendar at event time
+        CalendarIntents.viewCalendarEventWithFallback(context, CalendarProvider, event)
     }
 }
 
@@ -376,7 +382,7 @@ open class ViewEventActivityNoRecents : AppCompatActivity() {
 
             } else {
                 fab.setOnClickListener { _ ->
-                    CalendarIntents.viewCalendarEvent(this, event)
+                    openEventInCalendar(event)
                     finish()
                 }
             }
@@ -497,7 +503,7 @@ open class ViewEventActivityNoRecents : AppCompatActivity() {
                 }
 
                 R.id.action_open_in_calendar -> {
-                    CalendarIntents.viewCalendarEvent(this, event)
+                    openEventInCalendar(event)
                     finish()
                     true
                 }
@@ -555,7 +561,20 @@ open class ViewEventActivityNoRecents : AppCompatActivity() {
 
     @Suppress("unused", "UNUSED_PARAMETER")
     fun OnButtonEventDetailsClick(v: View?) {
-        CalendarIntents.viewCalendarEvent(this, event)
+        openEventInCalendar(event)
+    }
+
+    /**
+     * Opens an event in the calendar with fallback to time-based view if event not found.
+     * Shows a toast if the event was not found in the system calendar.
+     * 
+     * @see <a href="https://github.com/williscool/CalendarNotification/issues/66">Issue #66</a>
+     */
+    private fun openEventInCalendar(event: EventAlertRecord) {
+        val found = CalendarIntents.viewCalendarEventWithFallback(this, calendarProvider, event)
+        if (!found) {
+            Toast.makeText(this, R.string.event_not_found_opening_calendar_at_time, Toast.LENGTH_LONG).show()
+        }
     }
 
     private fun snoozeEvent(snoozeDelay: Long) {
@@ -852,7 +871,7 @@ open class ViewEventActivityNoRecents : AppCompatActivity() {
                 // Show
                 if (Settings(this).viewAfterEdit) {
                     handler.postDelayed({
-                        CalendarIntents.viewCalendarEvent(this, event)
+                        openEventInCalendar(event)
                         finish()
                     }, 100)
                 }

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

@@ -305,6 +305,7 @@
     <string name="event_was_created_reminder_at" formatted="false">Termin wurde erstellt, nächste Erinnerung: %s</string>
 
     <string name="event_not_found">Termin nicht gefunden</string>
+    <string name="event_not_found_opening_calendar_at_time">Termin nicht im Kalender gefunden - zeige Kalender zur Terminzeit</string>
     <string name="calendar_not_found">Kalender nicht gefunden</string>
     <string name="failed_to_update_event_details">Fehler beim Aktualisieren der Details</string>
     <string name="failed_to_move_event">Termin konnte nicht verschoben werden: </string>

android/app/src/main/res/values-pl/strings.xml

@@ -304,6 +304,7 @@
     <string name="event_was_created_reminder_at" formatted="false">Dodano wydarzenie, następne przypomnienie: %s</string>
 
     <string name="event_not_found">Nie znaleziono wydarzenia</string>
+    <string name="event_not_found_opening_calendar_at_time">Nie znaleziono wydarzenia w kalendarzu - pokazuję kalendarz w czasie wydarzenia</string>
     <string name="calendar_not_found">Nie znaleziono kalendarza</string>
     <string name="failed_to_update_event_details">Aktualizacja szczegółów wydarzenia nie powiodła się</string>
     <string name="failed_to_move_event">Nie powiodło się przeniesienie wydarzenia: </string>

android/app/src/main/res/values-ru/strings.xml

@@ -245,6 +245,7 @@
     <string name="event_was_created">Событие создано</string>
     <string name="event_was_created_reminder_at" formatted="false">Событие создано, сработает в: %s</string>
     <string name="event_not_found">Событие не найдено</string>
+    <string name="event_not_found_opening_calendar_at_time">Событие не найдено в календаре - показываю календарь на время события</string>
     <string name="calendar_not_found">Календарь не найден</string>
     <string name="failed_to_update_event_details">Не удалось обновить детали события</string>
     <string name="failed_to_move_event">Не удалось переместить событие: </string>

android/app/src/main/res/values-uk/strings.xml

@@ -244,6 +244,7 @@
     <string name="event_was_created">Подія створена</string>
     <string name="event_was_created_reminder_at" formatted="false">Подія створена, спрацює о: %s</string>
     <string name="event_not_found">Подія не знайдена</string>
+    <string name="event_not_found_opening_calendar_at_time">Подія не знайдена в календарі - показую календар на час події</string>
     <string name="calendar_not_found">Календар не знайдений</string>
     <string name="failed_to_update_event_details">Не вдалося оновити деталі події</string>
     <string name="failed_to_move_event">Не вдалося перемістити подію: </string>

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

@@ -340,6 +340,7 @@
     <string name="event_was_created_reminder_at" formatted="false">Event was created, next reminder: %s</string>
 
     <string name="event_not_found">Event not found</string>
+    <string name="event_not_found_opening_calendar_at_time">Event not found in calendar - showing calendar at event time</string>
     <string name="calendar_not_found">Calendar not found</string>
     <string name="failed_to_update_event_details">Failed to update event details</string>
     <string name="failed_to_move_event">Failed to move event: </string>