feat: show last message for ghost group (WPB-25285)

app/src/main/kotlin/com/wire/android/mapper/MessagePreviewContentMapper.kt

@@ -43,6 +43,10 @@ fun MessagePreview?.toUIPreview(
         return UILastMessageContent.None
     }
 
+    if (content is MessagePreviewContent.AdminlessDeleteReminder) {
+        return uiLastMessageContent(uiTextResolver)
+    }
+
     return when {
         // when unread event count is empty show last message
         unreadEventCount.isEmpty() -> uiLastMessageContent(uiTextResolver)
@@ -414,6 +418,9 @@ fun MessagePreview.uiLastMessageContent(uiTextResolver: UiTextResolver): UILastM
         }
 
         MessagePreviewContent.CryptoSessionReset -> UILastMessageContent.None
+        MessagePreviewContent.AdminlessDeleteReminder -> UILastMessageContent.TextMessage(
+            MessageBody(UIText.StringResource(R.string.last_message_adminless_delete_reminder))
+        )
         MessagePreviewContent.VerificationChanged.VerifiedMls ->
             UILastMessageContent.VerificationChanged(R.string.last_message_verified_conversation_mls)
 

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

@@ -1904,6 +1904,7 @@ In group conversations, the group admin can overwrite this setting.</string>
     <string name="label_system_message_apps_access_enabled_disclaimer">Added apps have access to the content of this conversation.</string>
     <string name="label_system_message_admin_role_assigned">You were promoted to group admin</string>
     <string name="label_system_message_adminless_delete_reminder">This group will be automatically deleted on %1$s, as there are no eligible group admins.</string>
+    <string name="last_message_adminless_delete_reminder">Will be deleted soon</string>
     <string name="more_information_about_this_server">More information about this backend</string>
 
     <!-- Pending messages service notification -->

app/src/test/kotlin/com/wire/android/mapper/MessagePreviewContentMapperTest.kt

@@ -49,6 +49,25 @@ class MessagePreviewContentMapperTest {
         override fun localeTag(): String = "test-locale"
     }
 
+    @Test
+    fun givenAdminlessDeleteReminder_whenMappingPreview_thenPendingDeleteSubtitleOverridesUnreadSummaries() = runTest {
+        val messagePreview = TestMessage.PREVIEW.copy(
+            content = MessagePreviewContent.AdminlessDeleteReminder
+        )
+        val unreadCounts = listOf(
+            emptyMap(),
+            mapOf(UnreadEventType.MENTION to 2, UnreadEventType.MISSED_CALL to 3)
+        )
+
+        unreadCounts.forEach { unreadEventCount ->
+            val textMessage = messagePreview.toUIPreview(unreadEventCount, uiTextResolver)
+                .shouldBeInstanceOf<UILastMessageContent.TextMessage>()
+            val result = textMessage.messageBody.message.shouldBeInstanceOf<UIText.StringResource>()
+
+            result.resId shouldBeEqualTo R.string.last_message_adminless_delete_reminder
+        }
+    }
+
     @Test
     fun givenMultipleUnreadEvents_whenMappingToUIPreview_thenCorrectSortedUILastMessageContentShouldBeReturned() = runTest {
         val messagePreview = TestMessage.PREVIEW.copy(