use std::fmt;use std::io;use std::io::stdout;use codex_terminal_detection::Multiplexer;use codex_terminal_detection::terminal_info;use crossterm::Command;use ratatui::crossterm::execute;#[derive(Debug)]pub struct Osc9Backend {    dcs_passthrough: bool,}impl Default for Osc9Backend {    fn default() -> Self {        Self::new()    }}impl Osc9Backend {    pub fn new() -> Self {        Self {            dcs_passthrough: matches!(terminal_info().multiplexer, Some(Multiplexer::Tmux { .. })),        }    }    pub fn notify(&mut self, message: &str) -> io::Result<()> {        execute!(            stdout(),            PostNotification {                message: message.to_string(),                dcs_passthrough: self.dcs_passthrough,            }        )    }}/// Command that emits an OSC 9 desktop notification with a message.#[derive(Debug, Clone)]pub struct PostNotification {    pub message: String,    pub dcs_passthrough: bool,}impl Command for PostNotification {    fn write_ansi(&self, f: &mut impl fmt::Write) -> fmt::Result {        if self.dcs_passthrough {            let escaped_message = escape_tmux_dcs_passthrough_payload(&self.message);            write!(f, "\x1bPtmux;\x1b\x1b]9;{escaped_message}\x07\x1b\\")        } else {            write!(f, "\x1b]9;{}\x07", self.message)        }    }    #[cfg(windows)]    fn execute_winapi(&self) -> io::Result<()> {        Err(std::io::Error::other(            "tried to execute PostNotification using WinAPI; use ANSI instead",        ))    }    #[cfg(windows)]    fn is_ansi_code_supported(&self) -> bool {        true    }}fn escape_tmux_dcs_passthrough_payload(message: &str) -> String {    message.replace('\u{1b}', "\u{1b}\u{1b}")}#[cfg(test)]mod tests {    use crossterm::Command;    use pretty_assertions::assert_eq;    use super::PostNotification;    #[test]    fn post_notification_writes_plain_osc9_sequence() {        let mut ansi = String::new();        let command = PostNotification {            message: "hello".to_string(),            dcs_passthrough: false,        };        command            .write_ansi(&mut ansi)            .expect("OSC 9 command should format");        assert_eq!(ansi, "\u{1b}]9;hello\u{7}");    }    #[test]    fn post_notification_writes_tmux_dcs_wrapped_osc9_sequence() {        let mut ansi = String::new();        let command = PostNotification {            message: "done".to_string(),            dcs_passthrough: true,        };        command            .write_ansi(&mut ansi)            .expect("OSC 9 command should format");        assert_eq!(ansi, "\u{1b}Ptmux;\u{1b}\u{1b}]9;done\u{7}\u{1b}\\");    }    #[test]    fn post_notification_escapes_escape_bytes_inside_tmux_payload() {        let mut ansi = String::new();        let command = PostNotification {            message: "danger\u{1b}[31m".to_string(),            dcs_passthrough: true,        };        command            .write_ansi(&mut ansi)            .expect("OSC 9 command should format");        assert_eq!(            ansi,            "\u{1b}Ptmux;\u{1b}\u{1b}]9;danger\u{1b}\u{1b}[31m\u{7}\u{1b}\\"        );    }}