1 files changed, 143 insertions, 0 deletions
diff --git a/src/terminal_notify.rs b/src/terminal_notify.rs
new file mode 100644
index 00000000..e6380c7b
--- /dev/null
+++ b/src/terminal_notify.rs
@@ -0,0 +1,143 @@
+use std::io::{self, Write as _};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum TerminalNotificationBackend {
+    Ghostty,
+    Iterm2,
+    Kitty,
+    WezTerm,
+}
+
+pub fn detect_backend() -> Option<TerminalNotificationBackend> {
+    let term_program = std::env::var("TERM_PROGRAM").ok();
+    let term = std::env::var("TERM").ok();
+
+    match term_program.as_deref() {
+        Some("ghostty") => return Some(TerminalNotificationBackend::Ghostty),
+        Some("iTerm.app") => return Some(TerminalNotificationBackend::Iterm2),
+        Some("WezTerm") => return Some(TerminalNotificationBackend::WezTerm),
+        _ => {}
+    }
+
+    if std::env::var_os("KITTY_WINDOW_ID").is_some() {
+        return Some(TerminalNotificationBackend::Kitty);
+    }
+
+    match term.as_deref() {
+        Some("xterm-ghostty") => Some(TerminalNotificationBackend::Ghostty),
+        Some("xterm-kitty") => Some(TerminalNotificationBackend::Kitty),
+        Some(term) if term.contains("wezterm") => Some(TerminalNotificationBackend::WezTerm),
+        _ => None,
+    }
+}
+
+pub fn show_notification(title: &str, body: Option<&str>) -> io::Result<bool> {
+    let Some(backend) = detect_backend() else {
+        return Ok(false);
+    };
+
+    let sequence = match backend {
+        TerminalNotificationBackend::Ghostty
+        | TerminalNotificationBackend::Iterm2
+        | TerminalNotificationBackend::WezTerm => build_osc9_notification(title, body),
+        TerminalNotificationBackend::Kitty => build_osc99_notification(title, body),
+    };
+
+    let sequence = if std::env::var_os("TMUX").is_some() {
+        wrap_tmux_passthrough(&sequence)
+    } else {
+        sequence
+    };
+
+    let mut stdout = io::stdout();
+    stdout.write_all(&sequence)?;
+    stdout.flush()?;
+    Ok(true)
+}
+
+pub fn split_message(message: &str) -> (&str, Option<&str>) {
+    match message.split_once(": ") {
+        Some((title, body)) if !title.is_empty() && !body.is_empty() => (title, Some(body)),
+        _ => (message, None),
+    }
+}
+
+fn build_osc9_notification(title: &str, body: Option<&str>) -> Vec<u8> {
+    let message = sanitize_text(match body {
+        Some(body) if !body.is_empty() => format!("{title}: {body}"),
+        _ => title.to_string(),
+    });
+    format!("\x1b]9;{message}\x1b\\").into_bytes()
+}
+
+fn build_osc99_notification(title: &str, body: Option<&str>) -> Vec<u8> {
+    let title = sanitize_text(title);
+    match body {
+        Some(body) if !body.is_empty() => {
+            let body = sanitize_text(body);
+            format!("\x1b]99;i=1:d=0;{title}\x1b\\\x1b]99;i=1:p=body;{body}\x1b\\").into_bytes()
+        }
+        _ => format!("\x1b]99;;{title}\x1b\\").into_bytes(),
+    }
+}
+
+fn sanitize_text(text: impl AsRef<str>) -> String {
+    text.as_ref()
+        .chars()
+        .filter(|ch| *ch != '\u{1b}' && *ch != '\u{7}' && *ch != '\u{9c}')
+        .map(|ch| match ch {
+            '\n' | '\r' | '\t' => ' ',
+            _ => ch,
+        })
+        .collect()
+}
+
+fn wrap_tmux_passthrough(sequence: &[u8]) -> Vec<u8> {
+    let mut wrapped = Vec::with_capacity(sequence.len() + 16);
+    wrapped.extend_from_slice(b"\x1bPtmux;");
+    for &byte in sequence {
+        if byte == 0x1b {
+            wrapped.push(0x1b);
+        }
+        wrapped.push(byte);
+    }
+    wrapped.extend_from_slice(b"\x1b\\");
+    wrapped
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn split_message_splits_title_and_body() {
+        assert_eq!(
+            split_message("agent done: ws · 1"),
+            ("agent done", Some("ws · 1"))
+        );
+    }
+
+    #[test]
+    fn split_message_leaves_plain_message_alone() {
+        assert_eq!(split_message("agent done"), ("agent done", None));
+    }
+
+    #[test]
+    fn sanitize_text_strips_control_bytes() {
+        assert_eq!(sanitize_text("a\n\tb\u{1b}c\u{7}"), "a  bc");
+    }
+
+    #[test]
+    fn kitty_notification_uses_structured_title_and_body() {
+        let sequence = String::from_utf8(build_osc99_notification("pi finished", Some("ws · 1")))
+            .expect("utf8");
+        assert!(sequence.contains("]99;i=1:d=0;pi finished"));
+        assert!(sequence.contains("]99;i=1:p=body;ws · 1"));
+    }
+
+    #[test]
+    fn tmux_passthrough_wraps_and_escapes() {
+        let wrapped = wrap_tmux_passthrough(b"\x1b]9;hi\x1b\\");
+        assert_eq!(wrapped, b"\x1bPtmux;\x1b\x1b]9;hi\x1b\x1b\\\x1b\\");
+    }
+}