feat: sync theme with host appearance

refs #675

2 files changed, 119 insertions, 10 deletions

diff --git a/src/client/input.rs b/src/client/input.rs
index add4990c..ba1e353f 100644
--- a/src/client/input.rs
+++ b/src/client/input.rs
@@ -59,6 +59,7 @@ fn unix_stdin_reader_loop(
     let mut framer = crate::raw_input::RawInputByteFramer::default();
     if host_color_query_sent {
         framer.host_color_query_sent();
+        framer.enable_host_color_scheme_change_tracking();
     }
 
     while !should_quit.load(Ordering::Acquire) {
@@ -75,7 +76,10 @@ fn unix_stdin_reader_loop(
                 }
 
                 if stdin_read_ready(&reader, 10) == Some(false) {
-                    for data in framer.flush_timeout() {
+                    let had_pending = framer.has_pending_input();
+                    let chunks = framer.flush_timeout();
+                    let held_escape = had_pending && chunks.is_empty();
+                    for data in chunks {
                         if event_tx
                             .blocking_send(ClientLoopEvent::StdinInput(data))
                             .is_err()
@@ -83,6 +87,16 @@ fn unix_stdin_reader_loop(
                             return;
                         }
                     }
+                    if held_escape && stdin_read_ready(&reader, 10) == Some(false) {
+                        for data in framer.flush_timeout() {
+                            if event_tx
+                                .blocking_send(ClientLoopEvent::StdinInput(data))
+                                .is_err()
+                            {
+                                return;
+                            }
+                        }
+                    }
                 }
             }
             Err(err) => {
@@ -268,6 +282,7 @@ fn windows_client_input_event_from_raw(
             Some(crate::protocol::ClientInputEvent::FocusLost)
         }
         crate::raw_input::RawInputEvent::HostDefaultColor { .. }
+        | crate::raw_input::RawInputEvent::HostColorSchemeChanged(_)
         | crate::raw_input::RawInputEvent::Unsupported => None,
     }
 }
diff --git a/src/client/mod.rs b/src/client/mod.rs
index 70d39559..834edd2b 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -329,6 +329,8 @@ fn setup_terminal_with_capabilities(
     mouse_capture: bool,
 ) -> io::Result<TerminalGuard> {
     ratatui::init();
+    let host_color_scheme_reports =
+        should_enable_host_color_scheme_reports(enable_client_protocols);
 
     if enable_client_protocols {
         if mouse_capture {
@@ -337,11 +339,19 @@ fn setup_terminal_with_capabilities(
             set_mouse_capture(false)?;
         }
         execute!(io::stdout(), EnableBracketedPaste, EnableFocusChange)?;
+        if host_color_scheme_reports {
+            write_host_color_scheme_report_mode(&mut io::stdout(), true)?;
+        }
         push_keyboard_enhancement_flags()?;
-    } else if mouse_capture {
-        set_mouse_capture(true)?;
     } else {
-        set_mouse_capture(false)?;
+        if should_query_host_terminal_theme() {
+            write_host_color_scheme_report_mode(&mut io::stdout(), false)?;
+        }
+        if mouse_capture {
+            set_mouse_capture(true)?;
+        } else {
+            set_mouse_capture(false)?;
+        }
     }
 
     let modify_other_keys_mode = enable_client_protocols
@@ -360,15 +370,42 @@ fn setup_terminal_with_capabilities(
 
     Ok(TerminalGuard {
         reset_modify_other_keys: modify_other_keys_mode.is_some(),
+        reset_host_color_scheme_reports: host_color_scheme_reports,
     })
 }
 
+fn should_enable_host_color_scheme_reports(enable_client_protocols: bool) -> bool {
+    enable_client_protocols && should_query_host_terminal_theme()
+}
+
 /// Guard that restores the terminal when dropped.
 struct TerminalGuard {
     reset_modify_other_keys: bool,
+    reset_host_color_scheme_reports: bool,
+}
+
+fn write_host_color_scheme_report_mode(
+    writer: &mut impl io::Write,
+    enabled: bool,
+) -> io::Result<()> {
+    let sequence = if enabled {
+        crate::terminal_theme::HOST_COLOR_SCHEME_REPORT_ENABLE_SEQUENCE
+    } else {
+        crate::terminal_theme::HOST_COLOR_SCHEME_REPORT_DISABLE_SEQUENCE
+    };
+    writer.write_all(sequence.as_bytes())?;
+    writer.flush()
 }
 
-fn write_terminal_restore_postlude(writer: &mut impl io::Write) -> io::Result<()> {
+fn write_terminal_restore_postlude(
+    writer: &mut impl io::Write,
+    reset_host_color_scheme_reports: bool,
+) -> io::Result<()> {
+    if reset_host_color_scheme_reports {
+        writer.write_all(
+            crate::terminal_theme::HOST_COLOR_SCHEME_REPORT_DISABLE_SEQUENCE.as_bytes(),
+        )?;
+    }
     // Restore a visible cursor and reset DECSCUSR back to the terminal default.
     writer.write_all(b"\x1b[?25h\x1b[0 q")?;
     writer.flush()
@@ -387,7 +424,7 @@ fn set_mouse_capture(enabled: bool) -> io::Result<()> {
     }
 }
 
-fn restore_terminal_state(reset_modify_other_keys: bool) {
+fn restore_terminal_state(reset_modify_other_keys: bool, reset_host_color_scheme_reports: bool) {
     let _ = clear_received_kitty_graphics(&mut io::stdout());
 
     // Reset modifyOtherKeys if we enabled it.
@@ -404,7 +441,7 @@ fn restore_terminal_state(reset_modify_other_keys: bool) {
         DisableMouseCapture
     );
     ratatui::restore();
-    let _ = write_terminal_restore_postlude(&mut io::stdout());
+    let _ = write_terminal_restore_postlude(&mut io::stdout(), reset_host_color_scheme_reports);
 }
 
 #[cfg(not(windows))]
@@ -432,7 +469,10 @@ fn pop_keyboard_enhancement_flags() -> io::Result<()> {
 
 impl Drop for TerminalGuard {
     fn drop(&mut self) {
-        restore_terminal_state(self.reset_modify_other_keys);
+        restore_terminal_state(
+            self.reset_modify_other_keys,
+            self.reset_host_color_scheme_reports,
+        );
     }
 }
 
@@ -704,9 +744,13 @@ fn run_client_with_mode(
 
     // Install a panic hook to restore the terminal on panic (same as monolithic).
     let panic_resets_modify_other_keys = terminal_guard.reset_modify_other_keys;
+    let panic_resets_host_color_scheme_reports = terminal_guard.reset_host_color_scheme_reports;
     let original_hook = std::panic::take_hook();
     std::panic::set_hook(Box::new(move |info| {
-        restore_terminal_state(panic_resets_modify_other_keys);
+        restore_terminal_state(
+            panic_resets_modify_other_keys,
+            panic_resets_host_color_scheme_reports,
+        );
         original_hook(info);
     }));
 
@@ -898,6 +942,9 @@ async fn run_client_loop(
                     ) {
                         state.request_full_redraw();
                     }
+                    if crate::raw_input::events_require_host_terminal_theme_query(&events) {
+                        query_host_terminal_theme();
+                    }
                     data
                 };
                 if should_bridge_clipboard_image_paste(&data, state.remote_image_paste_key) {
@@ -1601,17 +1648,64 @@ mod tests {
     }
 
     #[test]
+    fn write_host_color_scheme_report_mode_emits_mode_sequences() {
+        let mut output = Vec::new();
+        write_host_color_scheme_report_mode(&mut output, true).unwrap();
+        write_host_color_scheme_report_mode(&mut output, false).unwrap();
+
+        let mut expected = Vec::new();
+        expected.extend_from_slice(
+            crate::terminal_theme::HOST_COLOR_SCHEME_REPORT_ENABLE_SEQUENCE.as_bytes(),
+        );
+        expected.extend_from_slice(
+            crate::terminal_theme::HOST_COLOR_SCHEME_REPORT_DISABLE_SEQUENCE.as_bytes(),
+        );
+        assert_eq!(output, expected);
+    }
+
+    #[test]
+    fn color_scheme_change_event_requests_host_theme_query() {
+        let events = crate::raw_input::parse_raw_input_bytes_sync(b"\x1b[?997;1n");
+
+        assert!(crate::raw_input::events_require_host_terminal_theme_query(
+            &events
+        ));
+    }
+
+    #[test]
     fn host_terminal_theme_query_is_disabled_on_windows() {
         assert_eq!(should_query_host_terminal_theme(), !cfg!(windows));
     }
 
     #[test]
+    fn color_scheme_reports_are_enabled_only_for_full_clients() {
+        assert_eq!(
+            should_enable_host_color_scheme_reports(true),
+            !cfg!(windows)
+        );
+        assert!(!should_enable_host_color_scheme_reports(false));
+    }
+
+    #[test]
     fn terminal_restore_postlude_restores_visible_default_cursor() {
         let mut output = Vec::new();
-        write_terminal_restore_postlude(&mut output).unwrap();
+        write_terminal_restore_postlude(&mut output, false).unwrap();
         assert_eq!(output, b"\x1b[?25h\x1b[0 q");
     }
 
+    #[test]
+    fn terminal_restore_postlude_disables_color_scheme_reports_when_enabled() {
+        let mut output = Vec::new();
+        write_terminal_restore_postlude(&mut output, true).unwrap();
+
+        let mut expected = Vec::new();
+        expected.extend_from_slice(
+            crate::terminal_theme::HOST_COLOR_SCHEME_REPORT_DISABLE_SEQUENCE.as_bytes(),
+        );
+        expected.extend_from_slice(b"\x1b[?25h\x1b[0 q");
+        assert_eq!(output, expected);
+    }
+
     #[cfg(unix)]
     #[test]
     fn attach_escape_detaches_on_prefix_q() {