feat: TUI undo op (#5629)

codex-rs/tui/src/chatwidget.rs

@@ -37,6 +37,8 @@ use codex_core::protocol::TokenUsage;
 use codex_core::protocol::TokenUsageInfo;
 use codex_core::protocol::TurnAbortReason;
 use codex_core::protocol::TurnDiffEvent;
+use codex_core::protocol::UndoCompletedEvent;
+use codex_core::protocol::UndoStartedEvent;
 use codex_core::protocol::UserMessageEvent;
 use codex_core::protocol::ViewImageToolCallEvent;
 use codex_core::protocol::WebSearchBeginEvent;
@@ -113,16 +115,9 @@ use codex_core::protocol::AskForApproval;
 use codex_core::protocol::SandboxPolicy;
 use codex_core::protocol_config_types::ReasoningEffort as ReasoningEffortConfig;
 use codex_file_search::FileMatch;
-use codex_git_tooling::CreateGhostCommitOptions;
-use codex_git_tooling::GhostCommit;
-use codex_git_tooling::GitToolingError;
-use codex_git_tooling::create_ghost_commit;
-use codex_git_tooling::restore_ghost_commit;
 use codex_protocol::plan_tool::UpdatePlanArgs;
 use strum::IntoEnumIterator;
 
-const MAX_TRACKED_GHOST_COMMITS: usize = 20;
-
 // Track information about an in-flight exec command.
 struct RunningCommand {
     command: Vec<String>,
@@ -267,9 +262,6 @@ pub(crate) struct ChatWidget {
     pending_notification: Option<Notification>,
     // Simple review mode flag; used to adjust layout and banners.
     is_review_mode: bool,
-    // List of ghost commits corresponding to each turn.
-    ghost_snapshots: Vec<GhostCommit>,
-    ghost_snapshots_disabled: bool,
     // Whether to add a final message separator after the last message
     needs_final_message_separator: bool,
 
@@ -672,6 +664,31 @@ impl ChatWidget {
         debug!("BackgroundEvent: {message}");
     }
 
+    fn on_undo_started(&mut self, event: UndoStartedEvent) {
+        self.bottom_pane.ensure_status_indicator();
+        let message = event
+            .message
+            .unwrap_or_else(|| "Undo in progress...".to_string());
+        self.set_status_header(message);
+    }
+
+    fn on_undo_completed(&mut self, event: UndoCompletedEvent) {
+        let UndoCompletedEvent { success, message } = event;
+        self.bottom_pane.hide_status_indicator();
+        let message = message.unwrap_or_else(|| {
+            if success {
+                "Undo completed successfully.".to_string()
+            } else {
+                "Undo failed.".to_string()
+            }
+        });
+        if success {
+            self.add_info_message(message, None);
+        } else {
+            self.add_error_message(message);
+        }
+    }
+
     fn on_stream_error(&mut self, message: String) {
         if self.retry_status_header.is_none() {
             self.retry_status_header = Some(self.current_status_header.clone());
@@ -989,8 +1006,6 @@ impl ChatWidget {
             suppress_session_configured_redraw: false,
             pending_notification: None,
             is_review_mode: false,
-            ghost_snapshots: Vec::new(),
-            ghost_snapshots_disabled: true,
             needs_final_message_separator: false,
             last_rendered_width: std::cell::Cell::new(None),
             feedback,
@@ -1057,8 +1072,6 @@ impl ChatWidget {
             suppress_session_configured_redraw: true,
             pending_notification: None,
             is_review_mode: false,
-            ghost_snapshots: Vec::new(),
-            ghost_snapshots_disabled: true,
             needs_final_message_separator: false,
             last_rendered_width: std::cell::Cell::new(None),
             feedback,
@@ -1211,7 +1224,7 @@ impl ChatWidget {
                 self.app_event_tx.send(AppEvent::ExitRequest);
             }
             SlashCommand::Undo => {
-                self.undo_last_snapshot();
+                self.app_event_tx.send(AppEvent::CodexOp(Op::Undo));
             }
             SlashCommand::Diff => {
                 self.add_diff_in_progress();
@@ -1328,8 +1341,6 @@ impl ChatWidget {
             return;
         }
 
-        self.capture_ghost_snapshot();
-
         let mut items: Vec<UserInput> = Vec::new();
 
         if !text.is_empty() {
@@ -1362,57 +1373,6 @@ impl ChatWidget {
         self.needs_final_message_separator = false;
     }
 
-    fn capture_ghost_snapshot(&mut self) {
-        if self.ghost_snapshots_disabled {
-            return;
-        }
-
-        let options = CreateGhostCommitOptions::new(&self.config.cwd);
-        match create_ghost_commit(&options) {
-            Ok(commit) => {
-                self.ghost_snapshots.push(commit);
-                if self.ghost_snapshots.len() > MAX_TRACKED_GHOST_COMMITS {
-                    self.ghost_snapshots.remove(0);
-                }
-            }
-            Err(err) => {
-                self.ghost_snapshots_disabled = true;
-                let (message, hint) = match &err {
-                    GitToolingError::NotAGitRepository { .. } => (
-                        "Snapshots disabled: current directory is not a Git repository."
-                            .to_string(),
-                        None,
-                    ),
-                    _ => (
-                        format!("Snapshots disabled after error: {err}"),
-                        Some(
-                            "Restart Codex after resolving the issue to re-enable snapshots."
-                                .to_string(),
-                        ),
-                    ),
-                };
-                self.add_info_message(message, hint);
-                tracing::warn!("failed to create ghost snapshot: {err}");
-            }
-        }
-    }
-
-    fn undo_last_snapshot(&mut self) {
-        let Some(commit) = self.ghost_snapshots.pop() else {
-            self.add_info_message("No snapshot available to undo.".to_string(), None);
-            return;
-        };
-
-        if let Err(err) = restore_ghost_commit(&self.config.cwd, &commit) {
-            self.add_error_message(format!("Failed to restore snapshot: {err}"));
-            self.ghost_snapshots.push(commit);
-            return;
-        }
-
-        let short_id: String = commit.id().chars().take(8).collect();
-        self.add_info_message(format!("Restored workspace to snapshot {short_id}"), None);
-    }
-
     /// Replay a subset of initial events into the UI to seed the transcript when
     /// resuming an existing session. This approximates the live event flow and
     /// is intentionally conservative: only safe-to-replay items are rendered to
@@ -1510,6 +1470,8 @@ impl ChatWidget {
             EventMsg::BackgroundEvent(BackgroundEventEvent { message }) => {
                 self.on_background_event(message)
             }
+            EventMsg::UndoStarted(ev) => self.on_undo_started(ev),
+            EventMsg::UndoCompleted(ev) => self.on_undo_completed(ev),
             EventMsg::StreamError(StreamErrorEvent { message }) => self.on_stream_error(message),
             EventMsg::UserMessage(ev) => {
                 if from_replay {