feat(qt): close migration parity gaps

cx

crates/qbz-qt/src/deep_link_qt.rs

@@ -0,0 +1,96 @@
+//! Launcher deep links shared by cold starts and the Linux single-instance
+//! D-Bus handoff.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Mutex;
+
+static PENDING: Mutex<Option<String>> = Mutex::new(None);
+static ONLINE_SESSION: AtomicBool = AtomicBool::new(false);
+
+/// The native Qobuz URL shapes accepted by the desktop launcher files.
+pub(crate) fn is_qobuz_link(arg: &str) -> bool {
+    arg.starts_with("qobuzapp://")
+        || arg.starts_with("https://play.qobuz.com/")
+        || arg.starts_with("http://play.qobuz.com/")
+        || arg.starts_with("https://open.qobuz.com/")
+        || arg.starts_with("http://open.qobuz.com/")
+}
+
+fn select_link(args: &[String]) -> Option<String> {
+    args.iter().find(|arg| is_qobuz_link(arg)).cloned()
+}
+
+/// Capture argv before the single-instance decision so a duplicate process
+/// can forward its URL to the owner of the bus name.
+pub(crate) fn capture_argv() {
+    let args: Vec<String> = std::env::args().skip(1).collect();
+    if let Some(url) = select_link(&args) {
+        log::info!(
+            "[qbz-qt] deep link: captured {}",
+            url.split('?').next().unwrap_or(&url)
+        );
+        stash(url);
+    }
+}
+
+/// Newest launch intent wins, matching the former frontend.
+pub(crate) fn stash(url: String) {
+    if let Ok(mut pending) = PENDING.lock() {
+        *pending = Some(url);
+    }
+}
+
+pub(crate) fn take_pending() -> Option<String> {
+    PENDING.lock().ok().and_then(|mut pending| pending.take())
+}
+
+/// Bind/unbind the only context in which a Qobuz route can be fetched.
+pub(crate) fn set_online_session(active: bool) {
+    ONLINE_SESSION.store(active, Ordering::SeqCst);
+    if active {
+        drain_pending();
+    }
+}
+
+/// Resolve the pending link once an authenticated shell is available.
+pub(crate) fn drain_pending() {
+    if !ONLINE_SESSION.load(Ordering::SeqCst) {
+        return;
+    }
+    let Some(url) = take_pending() else {
+        return;
+    };
+    log::info!(
+        "[qbz-qt] deep link: resolving {}",
+        url.split('?').next().unwrap_or(&url)
+    );
+    crate::link_resolver_qt::resolve_deep_link(url);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn accepts_only_launcher_qobuz_shapes() {
+        assert!(is_qobuz_link("https://open.qobuz.com/album/a"));
+        assert!(is_qobuz_link("http://play.qobuz.com/track/1"));
+        assert!(is_qobuz_link("qobuzapp://artist/1"));
+        assert!(!is_qobuz_link("https://open.qobuz.com.evil.test/album/a"));
+        assert!(!is_qobuz_link("https://spotify.com/track/1"));
+        assert!(!is_qobuz_link("qbz://album/a"));
+    }
+
+    #[test]
+    fn first_matching_argument_wins() {
+        let args = vec![
+            "--flag".to_string(),
+            "https://open.qobuz.com/album/first".to_string(),
+            "qobuzapp://album/second".to_string(),
+        ];
+        assert_eq!(
+            select_link(&args),
+            Some("https://open.qobuz.com/album/first".to_string())
+        );
+    }
+}