From 3736e63a57f0c7770b5f1d79bd557685eddfb7b8 Mon Sep 17 00:00:00 2001
From: Damien Elmes <gpg@ankiweb.net>
Date: Sat, 8 May 2021 17:51:36 +1000
Subject: [PATCH] expose step counter and undone op changes in hook

---
 qt/aqt/operations/collection.py | 12 ++++++++----
 qt/tools/genhooks_gui.py        |  8 +++++++-
 rslib/backend.proto             |  1 +
 rslib/src/backend/ops.rs        |  1 +
 rslib/src/undo/mod.rs           |  3 +++
 5 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/qt/aqt/operations/collection.py b/qt/aqt/operations/collection.py
index 1eb130b8c4..373921b5bc 100644
--- a/qt/aqt/operations/collection.py
+++ b/qt/aqt/operations/collection.py
@@ -3,7 +3,7 @@
 
 from __future__ import annotations
 
-from anki.collection import LegacyCheckpoint, LegacyReviewUndo
+from anki.collection import LegacyCheckpoint, LegacyReviewUndo, OpChangesAfterUndo
 from anki.errors import UndoEmpty
 from anki.types import assert_exhaustive
 from aqt import gui_hooks
@@ -15,6 +15,10 @@
 def undo(*, parent: QWidget) -> None:
     "Undo the last operation, and refresh the UI."
 
+    def on_success(out: OpChangesAfterUndo) -> None:
+        gui_hooks.state_did_undo(out)
+        tooltip(tr.undo_action_undone(action=out.operation), parent=parent)
+
     def on_failure(exc: Exception) -> None:
         if isinstance(exc, UndoEmpty):
             # backend has no undo, but there may be a checkpoint
@@ -23,9 +27,9 @@ def on_failure(exc: Exception) -> None:
         else:
             showWarning(str(exc), parent=parent)
 
-    CollectionOp(parent, lambda col: col.undo()).success(
-        lambda out: tooltip(tr.undo_action_undone(action=out.operation), parent=parent)
-    ).failure(on_failure).run_in_background()
+    CollectionOp(parent, lambda col: col.undo()).success(on_success).failure(
+        on_failure
+    ).run_in_background()
 
 
 def _legacy_undo(*, parent: QWidget) -> None:
diff --git a/qt/tools/genhooks_gui.py b/qt/tools/genhooks_gui.py
index 8d194dbce5..42e7fb085f 100644
--- a/qt/tools/genhooks_gui.py
+++ b/qt/tools/genhooks_gui.py
@@ -27,6 +27,7 @@
 from anki.decks import DeckDict, DeckConfigDict
 from anki.hooks import runFilter, runHook
 from anki.models import NotetypeDict
+from anki.collection import OpChangesAfterUndo
 from aqt.qt import QDialog, QEvent, QMenu, QWidget
 from aqt.tagedit import TagEdit
 """
@@ -475,7 +476,12 @@ def on_browser_will_build_tree(handled, root, stage, browser):
         name="state_did_revert",
         args=["action: str"],
         legacy_hook="revertedState",
-        doc="Called when user used the undo option to restore to an earlier database state.",
+        doc="Legacy hook, called after undoing.",
+    ),
+    Hook(
+        name="state_did_undo",
+        args=["changes: OpChangesAfterUndo"],
+        doc="Called after backend undoes a change.",
     ),
     Hook(
         name="state_did_reset",
diff --git a/rslib/backend.proto b/rslib/backend.proto
index 32d72d873a..0ca84af7bb 100644
--- a/rslib/backend.proto
+++ b/rslib/backend.proto
@@ -1562,6 +1562,7 @@ message OpChangesAfterUndo {
   string operation = 2;
   int64 reverted_to_timestamp = 3;
   UndoStatus new_status = 4;
+  uint32 counter = 5;
 }
 
 message DefaultsForAddingIn {
diff --git a/rslib/src/backend/ops.rs b/rslib/src/backend/ops.rs
index 0f9c436360..2d6c7fa2b8 100644
--- a/rslib/src/backend/ops.rs
+++ b/rslib/src/backend/ops.rs
@@ -67,6 +67,7 @@ impl OpOutput<UndoOutput> {
             operation: self.output.undone_op.describe(tr),
             reverted_to_timestamp: self.output.reverted_to.0,
             new_status: Some(self.output.new_undo_status.into_protobuf(tr)),
+            counter: self.output.counter as u32,
         }
     }
 }
diff --git a/rslib/src/undo/mod.rs b/rslib/src/undo/mod.rs
index 1cf1ab94d2..5f79e3ae6d 100644
--- a/rslib/src/undo/mod.rs
+++ b/rslib/src/undo/mod.rs
@@ -61,6 +61,7 @@ pub struct UndoOutput {
     pub undone_op: Op,
     pub reverted_to: TimestampSecs,
     pub new_undo_status: UndoStatus,
+    pub counter: usize,
 }
 
 #[derive(Debug, Default)]
@@ -285,6 +286,7 @@ impl Collection {
         let undone_op = step.kind;
         let reverted_to = step.timestamp;
         let changes = step.changes;
+        let counter = step.counter;
         self.state.undo.mode = mode;
         let res = self.transact(undone_op.clone(), |col| {
             for change in changes.into_iter().rev() {
@@ -294,6 +296,7 @@ impl Collection {
                 undone_op,
                 reverted_to,
                 new_undo_status: col.undo_status(),
+                counter,
             })
         });
         self.state.undo.mode = UndoMode::NormalOp;