properly clean up old Google Sync events at new CalDAV system

app/src/main/kotlin/com/simplemobiletools/calendar/activities/MainActivity.kt

@@ -95,6 +95,12 @@ class MainActivity : SimpleActivity(), NavigationListener {
         }
 
         recheckCalDAVCalendars {}
+
+        if (config.googleSync) {
+            val ids = dbHelper.getGoogleSyncEvents().map { it.id.toString() }.toTypedArray()
+            dbHelper.deleteEvents(ids, false)
+            config.googleSync = false
+        }
     }
 
     override fun onResume() {

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/Config.kt

@@ -71,6 +71,10 @@ class Config(context: Context) : BaseConfig(context) {
         get() = prefs.getInt(FONT_SIZE, FONT_SIZE_MEDIUM)
         set(size) = prefs.edit().putInt(FONT_SIZE, size).apply()
 
+    var googleSync: Boolean
+        get() = prefs.getBoolean(GOOGLE_SYNC, false)
+        set(googleSync) = prefs.edit().putBoolean(GOOGLE_SYNC, googleSync).apply()
+
     var caldavSync: Boolean
         get() = prefs.getBoolean(CALDAV_SYNC, false)
         set(caldavSync) {

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/Constants.kt

@@ -47,6 +47,7 @@ val CALDAV_SYNCED_CALENDAR_IDS = "caldav_synced_calendar_ids"
 val LAST_USED_CALDAV_CALENDAR = "last_used_caldav_calendar"
 val SNOOZE_DELAY = "snooze_delay"
 val DISPLAY_PAST_EVENTS = "display_past_events"
+val GOOGLE_SYNC = "google_sync" // deprecated
 
 val letterIDs = intArrayOf(R.string.sunday_letter, R.string.monday_letter, R.string.tuesday_letter, R.string.wednesday_letter,
         R.string.thursday_letter, R.string.friday_letter, R.string.saturday_letter)
@@ -121,3 +122,6 @@ val FONT_SIZE_LARGE = 2
 
 val SOURCE_SIMPLE_CALENDAR = "simple-calendar"
 val SOURCE_IMPORTED_ICS = "imported-ics"
+
+// deprecated
+val SOURCE_GOOGLE_CALENDAR = 1

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/DBHelper.kt

@@ -37,6 +37,7 @@ class DBHelper private constructor(val context: Context) : SQLiteOpenHelper(cont
     private val COL_IS_DST_INCLUDED = "is_dst_included"
     private val COL_LAST_UPDATED = "last_updated"
     private val COL_EVENT_SOURCE = "event_source"
+    private val COL_SOURCE = "source"   // deprecated
 
     private val META_TABLE_NAME = "events_meta"
     private val COL_EVENT_ID = "event_id"
@@ -697,6 +698,12 @@ class DBHelper private constructor(val context: Context) : SQLiteOpenHelper(cont
         return getEvents(selection) as ArrayList<Event>
     }
 
+    // get deprecated Google Sync events
+    fun getGoogleSyncEvents(): ArrayList<Event> {
+        val selection = "$MAIN_TABLE_NAME.$COL_SOURCE = $SOURCE_GOOGLE_CALENDAR"
+        return getEvents(selection) as ArrayList<Event>
+    }
+
     fun getEventsAtReboot(): List<Event> {
         val selection = "$COL_REMINDER_MINUTES != -1 AND ($COL_START_TS > ? OR $COL_REPEAT_INTERVAL != 0) AND $COL_START_TS != 0"
         val selectionArgs = arrayOf(DateTime.now().seconds().toString())