From 3817bc61bb8f31daa99eb75e904c391969062a0f Mon Sep 17 00:00:00 2001
From: David Allison <62114487+david-allison@users.noreply.github.com>
Date: Thu, 16 Jan 2025 21:27:44 +0000
Subject: [PATCH] feat(deck-picker): make 'empty filtered' undoable

---
 .../src/main/java/com/ichi2/anki/DeckPicker.kt    |  2 +-
 .../ichi2/anki/deckpicker/DeckPickerViewModel.kt  |  3 +--
 .../java/com/ichi2/libanki/sched/Scheduler.kt     |  4 +---
 .../anki/deckpicker/DeckPickerViewModelTest.kt    | 15 +++++++++++++++
 4 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/AnkiDroid/src/main/java/com/ichi2/anki/DeckPicker.kt b/AnkiDroid/src/main/java/com/ichi2/anki/DeckPicker.kt
index 050999cee194..91a7a8b4e4d8 100644
--- a/AnkiDroid/src/main/java/com/ichi2/anki/DeckPicker.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/anki/DeckPicker.kt
@@ -2662,7 +2662,7 @@ open class DeckPicker :
         changes: OpChanges,
         handler: Any?,
     ) {
-        if (changes.studyQueues && handler !== this) {
+        if (changes.studyQueues && handler !== this && handler !== viewModel) {
             invalidateOptionsMenu()
             if (!activityPaused) {
                 // No need to update while the activity is paused, because `onResume` calls `refreshState` that calls `updateDeckList`.
diff --git a/AnkiDroid/src/main/java/com/ichi2/anki/deckpicker/DeckPickerViewModel.kt b/AnkiDroid/src/main/java/com/ichi2/anki/deckpicker/DeckPickerViewModel.kt
index 3339fc17ff89..2b478a224eaa 100644
--- a/AnkiDroid/src/main/java/com/ichi2/anki/deckpicker/DeckPickerViewModel.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/anki/deckpicker/DeckPickerViewModel.kt
@@ -102,12 +102,11 @@ class DeckPickerViewModel : ViewModel() {
         }
 
     // TODO: move withProgress to the ViewModel, so we don't return 'Job'
-    // TODO: undoableOp { } on emptyDyn
     fun emptyFilteredDeck(deckId: DeckId): Job =
         viewModelScope.launch {
             Timber.i("empty filtered deck %s", deckId)
             withCol { decks.select(deckId) }
-            withCol { sched.emptyDyn(decks.selected()) }
+            undoableOp { sched.emptyDyn(decks.selected()) }
             flowOfDeckCountsChanged.emit(Unit)
         }
 }
diff --git a/AnkiDroid/src/main/java/com/ichi2/libanki/sched/Scheduler.kt b/AnkiDroid/src/main/java/com/ichi2/libanki/sched/Scheduler.kt
index ff1d0612373a..c0cb9303f98f 100644
--- a/AnkiDroid/src/main/java/com/ichi2/libanki/sched/Scheduler.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/libanki/sched/Scheduler.kt
@@ -449,9 +449,7 @@ open class Scheduler(
     /** Remove all cards from a dynamic deck
      * @param did The deck to empty. 0 means current deck.
      */
-    open fun emptyDyn(did: DeckId) {
-        col.backend.emptyFilteredDeck(did)
-    }
+    open fun emptyDyn(did: DeckId) = col.backend.emptyFilteredDeck(did)
 
     fun deckDueTree(): DeckNode = deckTree(true)
 
diff --git a/AnkiDroid/src/test/java/com/ichi2/anki/deckpicker/DeckPickerViewModelTest.kt b/AnkiDroid/src/test/java/com/ichi2/anki/deckpicker/DeckPickerViewModelTest.kt
index ef5a2a20ff6f..2bdf421a7f94 100644
--- a/AnkiDroid/src/test/java/com/ichi2/anki/deckpicker/DeckPickerViewModelTest.kt
+++ b/AnkiDroid/src/test/java/com/ichi2/anki/deckpicker/DeckPickerViewModelTest.kt
@@ -116,6 +116,21 @@ class DeckPickerViewModelTest : RobolectricTest() {
         }
     }
 
+    @Test
+    fun `empty filtered - undoable`() {
+        runTest {
+            val filteredDeckId = moveAllCardsToFilteredDeck()
+
+            // ChangeManager assert
+            ensureOpsExecuted(1) {
+                viewModel.emptyFilteredDeck(filteredDeckId).join()
+            }
+
+            // backend assert
+            assertThat("col undo status", col.undoStatus().undo, equalTo("Empty"))
+        }
+    }
+
     @CheckResult
     private suspend fun createEmptyCards(): List<CardId> {
         addNoteUsingNoteTypeName("Cloze", "{{c1::Hello}} {{c2::World}}", "").apply {