Enable removal of multiple tags from the sidebar

qt/aqt/sidebar.py

@@ -349,7 +349,7 @@ class SidebarTreeView(QTreeView):
             ),
             SidebarItemType.TAG: (
                 (tr(TR.ACTIONS_RENAME), self.rename_tag),
-                (tr(TR.ACTIONS_DELETE), self.remove_tag),
+                (tr(TR.ACTIONS_DELETE), self.remove_tags),
             ),
             SidebarItemType.SAVED_SEARCH: (
                 (tr(TR.ACTIONS_RENAME), self.rename_saved_search),
@@ -1081,15 +1081,14 @@ class SidebarTreeView(QTreeView):
         self.refresh()
         self.mw.deckBrowser.refresh()
 
-    def remove_tag(self, item: SidebarItem) -> None:
-        self.browser.editor.saveNow(lambda: self._remove_tag(item))
+    def remove_tags(self, item: SidebarItem) -> None:
+        self.browser.editor.saveNow(lambda: self._remove_tags(item))
 
-    def _remove_tag(self, item: SidebarItem) -> None:
-        old_name = item.full_name
+    def _remove_tags(self, _item: SidebarItem) -> None:
+        tags = self._selected_tags()
 
         def do_remove() -> None:
-            self.mw.col.tags.remove(old_name)
-            self.col.tags.rename(old_name, "")
+            self.col._backend.expunge_tags(" ".join(tags))
 
         def on_done(fut: Future) -> None:
             self.mw.requireReset(reason=ResetReason.BrowserRemoveTags, context=self)
@@ -1246,3 +1245,10 @@ class SidebarTreeView(QTreeView):
             for item in self._selected_items()
             if item.item_type == SidebarItemType.SAVED_SEARCH
         ]
+
+    def _selected_tags(self) -> List[str]:
+        return [
+            item.full_name
+            for item in self._selected_items()
+            if item.item_type == SidebarItemType.TAG
+        ]

rslib/backend.proto

@@ -225,6 +225,7 @@ service BackendService {
 
   rpc ClearUnusedTags(Empty) returns (Empty);
   rpc AllTags(Empty) returns (StringList);
+  rpc ExpungeTags(String) returns (Empty);
   rpc SetTagExpanded(SetTagExpandedIn) returns (Empty);
   rpc ClearTag(String) returns (Empty);
   rpc TagTree(Empty) returns (TagTreeNode);

rslib/src/backend/mod.rs

@@ -1418,6 +1418,13 @@ impl BackendService for Backend {
         })
     }
 
+    fn expunge_tags(&self, tags: pb::String) -> BackendResult<pb::Empty> {
+        self.with_col(|col| {
+            col.expunge_tags(tags.val.as_str())?;
+            Ok(().into())
+        })
+    }
+
     fn set_tag_expanded(&self, input: pb::SetTagExpandedIn) -> BackendResult<pb::Empty> {
         self.with_col(|col| {
             col.transact(None, |col| {

rslib/src/err.rs

@@ -487,3 +487,11 @@ impl From<ParseIntError> for AnkiError {
         AnkiError::ParseNumError
     }
 }
+
+impl From<regex::Error> for AnkiError {
+    fn from(_err: regex::Error) -> Self {
+        AnkiError::InvalidInput {
+            info: "invalid regex".into(),
+        }
+    }
+}

rslib/src/notes.rs

@@ -152,6 +152,12 @@ impl Note {
             .collect()
     }
 
+    pub(crate) fn remove_tags(&mut self, re: &Regex) -> bool {
+        let old_len = self.tags.len();
+        self.tags.retain(|tag| !re.is_match(tag));
+        old_len > self.tags.len()
+    }
+
     pub(crate) fn replace_tags<T: Replacer>(&mut self, re: &Regex, mut repl: T) -> bool {
         let mut changed = false;
         for tag in &mut self.tags {

rslib/src/storage/tag/mod.rs

@@ -73,6 +73,15 @@ impl SqliteStorage {
         Ok(())
     }
 
+    /// Clear all matching tags where tag_group is a regexp group that should not match whitespace.
+    pub(crate) fn clear_tag_group(&self, tag_group: &str) -> Result<()> {
+        self.db
+            .prepare_cached("delete from tags where tag regexp ?")?
+            .execute(&[format!("(?i)^{}($|::)", tag_group)])?;
+
+        Ok(())
+    }
+
     pub(crate) fn set_tag_collapsed(&self, tag: &str, collapsed: bool) -> Result<()> {
         self.db
             .prepare_cached("update tags set collapsed = ? where tag = ?")?

rslib/src/tags.rs

@@ -285,6 +285,37 @@ impl Collection {
         Ok(())
     }
 
+    /// Take tags as a whitespace-separated string and remove them from all notes and the storage.
+    pub fn expunge_tags(&mut self, tags: &str) -> Result<usize> {
+        let tag_group = format!("({})", regex::escape(tags.trim()).replace(' ', "|"));
+        let nids = self.nids_for_tags(&tag_group)?;
+        let re = Regex::new(&format!("(?i)^{}(::.*)?$", tag_group))?;
+        self.transact(None, |col| {
+            col.storage.clear_tag_group(&tag_group)?;
+            col.transform_notes(&nids, |note, _nt| {
+                Ok(TransformNoteOutput {
+                    changed: note.remove_tags(&re),
+                    generate_cards: false,
+                    mark_modified: true,
+                })
+            })
+        })
+    }
+
+    /// Take tags as a regexp group, i.e. separated with pipes and wrapped in brackets, and return
+    /// the ids of all notes with one of them.
+    fn nids_for_tags(&mut self, tag_group: &str) -> Result<Vec<NoteID>> {
+        let mut stmt = self
+            .storage
+            .db
+            .prepare("select id from notes where tags regexp ?")?;
+        let args = format!("(?i).* {}(::| ).*", tag_group);
+        let nids = stmt
+            .query_map(&[args], |row| row.get(0))?
+            .collect::<std::result::Result<_, _>>()?;
+        Ok(nids)
+    }
+
     pub(crate) fn set_tag_expanded(&self, name: &str, expanded: bool) -> Result<()> {
         let mut name = name;
         let tag;