fix(context left after review): review footer context after /review (#5610)

## Summary
- show live review token usage while `/review` runs and restore the main
session indicator afterward
  - add regression coverage for the footer behavior

## Testing
  - just fmt
  - cargo test -p codex-tui

Fixes #5604

---------

Signed-off-by: Fahad <fahad@2doapp.com>

codex-rs/tui/src/bottom_pane/mod.rs

@@ -114,6 +114,11 @@ impl BottomPane {
         self.status.as_ref()
     }
 
+    #[cfg(test)]
+    pub(crate) fn context_window_percent(&self) -> Option<i64> {
+        self.context_window_percent
+    }
+
     fn active_view(&self) -> Option<&dyn BottomPaneView> {
         self.view_stack.last().map(std::convert::AsRef::as_ref)
     }

codex-rs/tui/src/chatwidget.rs

@@ -290,6 +290,8 @@ pub(crate) struct ChatWidget {
     pending_notification: Option<Notification>,
     // Simple review mode flag; used to adjust layout and banners.
     is_review_mode: bool,
+    // Snapshot of token usage to restore after review mode exits.
+    pre_review_token_info: Option<Option<TokenUsageInfo>>,
     // Whether to add a final message separator after the last message
     needs_final_message_separator: bool,
 
@@ -489,16 +491,39 @@ impl ChatWidget {
     }
 
     pub(crate) fn set_token_info(&mut self, info: Option<TokenUsageInfo>) {
-        if let Some(info) = info {
-            let context_window = info
-                .model_context_window
-                .or(self.config.model_context_window);
-            let percent = context_window.map(|window| {
+        match info {
+            Some(info) => self.apply_token_info(info),
+            None => {
+                self.bottom_pane.set_context_window_percent(None);
+                self.token_info = None;
+            }
+        }
+    }
+
+    fn apply_token_info(&mut self, info: TokenUsageInfo) {
+        let percent = self.context_remaining_percent(&info);
+        self.bottom_pane.set_context_window_percent(percent);
+        self.token_info = Some(info);
+    }
+
+    fn context_remaining_percent(&self, info: &TokenUsageInfo) -> Option<i64> {
+        info.model_context_window
+            .or(self.config.model_context_window)
+            .map(|window| {
                 info.last_token_usage
                     .percent_of_context_window_remaining(window)
-            });
-            self.bottom_pane.set_context_window_percent(percent);
-            self.token_info = Some(info);
+            })
+    }
+
+    fn restore_pre_review_token_info(&mut self) {
+        if let Some(saved) = self.pre_review_token_info.take() {
+            match saved {
+                Some(info) => self.apply_token_info(info),
+                None => {
+                    self.bottom_pane.set_context_window_percent(None);
+                    self.token_info = None;
+                }
+            }
         }
     }
 
@@ -1150,6 +1175,7 @@ impl ChatWidget {
             suppress_session_configured_redraw: false,
             pending_notification: None,
             is_review_mode: false,
+            pre_review_token_info: None,
             needs_final_message_separator: false,
             last_rendered_width: std::cell::Cell::new(None),
             feedback,
@@ -1223,6 +1249,7 @@ impl ChatWidget {
             suppress_session_configured_redraw: true,
             pending_notification: None,
             is_review_mode: false,
+            pre_review_token_info: None,
             needs_final_message_separator: false,
             last_rendered_width: std::cell::Cell::new(None),
             feedback,
@@ -1693,6 +1720,9 @@ impl ChatWidget {
 
     fn on_entered_review_mode(&mut self, review: ReviewRequest) {
         // Enter review mode and emit a concise banner
+        if self.pre_review_token_info.is_none() {
+            self.pre_review_token_info = Some(self.token_info.clone());
+        }
         self.is_review_mode = true;
         let banner = format!(">> Code review started: {} <<", review.user_facing_hint);
         self.add_to_history(history_cell::new_review_status_line(banner));
@@ -1733,6 +1763,7 @@ impl ChatWidget {
         }
 
         self.is_review_mode = false;
+        self.restore_pre_review_token_info();
         // Append a finishing banner at the end of this turn.
         self.add_to_history(history_cell::new_review_status_line(
             "<< Code review finished >>".to_string(),

codex-rs/tui/src/chatwidget/tests.rs

@@ -38,6 +38,9 @@ use codex_core::protocol::ReviewRequest;
 use codex_core::protocol::StreamErrorEvent;
 use codex_core::protocol::TaskCompleteEvent;
 use codex_core::protocol::TaskStartedEvent;
+use codex_core::protocol::TokenCountEvent;
+use codex_core::protocol::TokenUsage;
+use codex_core::protocol::TokenUsageInfo;
 use codex_core::protocol::UndoCompletedEvent;
 use codex_core::protocol::UndoStartedEvent;
 use codex_core::protocol::ViewImageToolCallEvent;
@@ -215,6 +218,81 @@ fn exited_review_mode_emits_results_and_finishes() {
     assert!(!chat.is_review_mode);
 }
 
+/// Exiting review restores the pre-review context window indicator.
+#[test]
+fn review_restores_context_window_indicator() {
+    let (mut chat, mut rx, _ops) = make_chatwidget_manual();
+
+    let context_window = 13_000;
+    let pre_review_tokens = 12_700; // ~30% remaining after subtracting baseline.
+    let review_tokens = 12_030; // ~97% remaining after subtracting baseline.
+
+    chat.handle_codex_event(Event {
+        id: "token-before".into(),
+        msg: EventMsg::TokenCount(TokenCountEvent {
+            info: Some(make_token_info(pre_review_tokens, context_window)),
+            rate_limits: None,
+        }),
+    });
+    assert_eq!(chat.bottom_pane.context_window_percent(), Some(30));
+
+    chat.handle_codex_event(Event {
+        id: "review-start".into(),
+        msg: EventMsg::EnteredReviewMode(ReviewRequest {
+            prompt: "Review the latest changes".to_string(),
+            user_facing_hint: "feature branch".to_string(),
+            append_to_original_thread: true,
+        }),
+    });
+
+    chat.handle_codex_event(Event {
+        id: "token-review".into(),
+        msg: EventMsg::TokenCount(TokenCountEvent {
+            info: Some(make_token_info(review_tokens, context_window)),
+            rate_limits: None,
+        }),
+    });
+    assert_eq!(chat.bottom_pane.context_window_percent(), Some(97));
+
+    chat.handle_codex_event(Event {
+        id: "review-end".into(),
+        msg: EventMsg::ExitedReviewMode(ExitedReviewModeEvent {
+            review_output: None,
+        }),
+    });
+    let _ = drain_insert_history(&mut rx);
+
+    assert_eq!(chat.bottom_pane.context_window_percent(), Some(30));
+    assert!(!chat.is_review_mode);
+}
+
+/// Receiving a TokenCount event without usage clears the context indicator.
+#[test]
+fn token_count_none_resets_context_indicator() {
+    let (mut chat, _rx, _ops) = make_chatwidget_manual();
+
+    let context_window = 13_000;
+    let pre_compact_tokens = 12_700;
+
+    chat.handle_codex_event(Event {
+        id: "token-before".into(),
+        msg: EventMsg::TokenCount(TokenCountEvent {
+            info: Some(make_token_info(pre_compact_tokens, context_window)),
+            rate_limits: None,
+        }),
+    });
+    assert_eq!(chat.bottom_pane.context_window_percent(), Some(30));
+
+    chat.handle_codex_event(Event {
+        id: "token-cleared".into(),
+        msg: EventMsg::TokenCount(TokenCountEvent {
+            info: None,
+            rate_limits: None,
+        }),
+    });
+    assert_eq!(chat.bottom_pane.context_window_percent(), None);
+}
+
 #[cfg_attr(
     target_os = "macos",
     ignore = "system configuration APIs are blocked under macOS seatbelt"
@@ -292,6 +370,7 @@ fn make_chatwidget_manual() -> (
         suppress_session_configured_redraw: false,
         pending_notification: None,
         is_review_mode: false,
+        pre_review_token_info: None,
         needs_final_message_separator: false,
         last_rendered_width: std::cell::Cell::new(None),
         feedback: codex_feedback::CodexFeedback::new(),
@@ -338,6 +417,21 @@ fn lines_to_single_string(lines: &[ratatui::text::Line<'static>]) -> String {
     s
 }
 
+fn make_token_info(total_tokens: i64, context_window: i64) -> TokenUsageInfo {
+    fn usage(total_tokens: i64) -> TokenUsage {
+        TokenUsage {
+            total_tokens,
+            ..TokenUsage::default()
+        }
+    }
+
+    TokenUsageInfo {
+        total_token_usage: usage(total_tokens),
+        last_token_usage: usage(total_tokens),
+        model_context_window: Some(context_window),
+    }
+}
+
 #[test]
 fn rate_limit_warnings_emit_thresholds() {
     let mut state = RateLimitWarningState::default();