Tell the user when a newer Rig Hub is out

src/main.rs

@@ -99,6 +99,57 @@ fn open_url(url: &str) {
     let _ = webbrowser::open(url);
 }
 
+// ------------------------------------------------------------- update check
+
+/// (major, minor, patch, (pre-release kind, number)); a release is kind 3, above alpha/beta/rc.
+type Ver = (u32, u32, u32, (u8, u32));
+
+fn ver(v: &str) -> Option<Ver> {
+    let (core, pre) = match v.split_once('-') {
+        Some((c, p)) => (c, Some(p)),
+        None => (v, None),
+    };
+    let mut n = core.split('.');
+    let mut num = || n.next()?.parse().ok();
+    let nums = (num()?, num()?, num()?);
+    if n.next().is_some() {
+        return None; // 1.2.3.4 isn't a version we ship
+    }
+    let (name, n) = match pre {
+        Some(p) => p.split_once('.').unwrap_or((p, "0")),
+        None => return Some((nums.0, nums.1, nums.2, (3, 0))),
+    };
+    let kind = match name {
+        "alpha" => 0,
+        "beta" => 1,
+        "rc" => 2,
+        _ => return None,
+    };
+    Some((nums.0, nums.1, nums.2, (kind, n.parse().ok()?)))
+}
+
+/// True only when `latest` really is ahead: garbage on either side means no update.
+fn is_newer(latest: &str, current: &str) -> bool {
+    match (ver(latest), ver(current)) {
+        (Some(l), Some(c)) => l > c,
+        _ => false,
+    }
+}
+
+/// The tag out of curl -I's `location:` header, without the leading "v".
+fn latest_tag(headers: &str) -> Option<&str> {
+    let url = headers
+        .lines()
+        .rev()
+        .find(|l| l.trim_start().get(..9).is_some_and(|p| p.eq_ignore_ascii_case("location:")))?
+        .split_once(':')?
+        .1
+        .trim();
+    let tag = url.split("/tag/").nth(1)?.split('/').next()?;
+    let tag = tag.strip_prefix('v').unwrap_or(tag);
+    ver(tag).is_some().then_some(tag)
+}
+
 fn bug_report_url(st: &State) -> String {
     fn line<T>(d: &Dev<T>, name: impl Fn(&T) -> String) -> String {
         match d {
@@ -763,6 +814,11 @@ impl App {
             if ui.add(egui::Button::new("🐞  Report a bug").min_size(vec2(ui.available_width(), 34.0))).clicked() {
                 open_url(&bug_report_url(st));
             }
+            if let Some(latest) = &st.update
+                && ui.small_button(format!("⬆  Rig Hub {latest} is out")).on_hover_text("Opens the release page").clicked()
+            {
+                open_url(&format!("{REPO}/releases/latest"));
+            }
             if let Some(h) = st.headset.ok() {
                 let text = match h.battery {
                     audio::Battery::Level(n) => format!("🎧 {n}%"),
@@ -1413,6 +1469,48 @@ fn main() -> eframe::Result {
     }
 }
 
+#[cfg(test)]
+mod update_tests {
+    use super::{is_newer, latest_tag};
+
+    #[test]
+    fn newer_same_older() {
+        assert!(is_newer("0.1.1", "0.1.0"));
+        assert!(!is_newer("0.1.0", "0.1.0")); // same: no update
+        assert!(!is_newer("0.1.0", "0.1.1")); // older
+        assert!(is_newer("0.2.0", "0.1.9"));
+        assert!(is_newer("1.0.0", "0.9.9"));
+    }
+
+    #[test]
+    fn pre_releases_compare_numerically_and_below_their_release() {
+        assert!(is_newer("0.1.0-alpha.10", "0.1.0-alpha.3")); // numeric, not "10" < "3"
+        assert!(!is_newer("0.1.0-alpha.3", "0.1.0-alpha.10"));
+        assert!(is_newer("0.1.0-beta.1", "0.1.0-alpha.10"));
+        assert!(is_newer("0.1.0", "0.1.0-beta.1"));
+        assert!(is_newer("0.1.0", "0.1.0-alpha.3"));
+        assert!(is_newer("0.1.1-alpha.1", "0.1.0")); // newer core beats older pre-release
+    }
+
+    #[test]
+    fn garbage_means_no_update() {
+        assert!(!is_newer("", "0.1.0"));
+        assert!(!is_newer("banana", "0.1.0"));
+        assert!(!is_newer("0.1", "0.1.0"));
+        assert!(!is_newer("0.1.0-omega.5", "0.1.0-alpha.3")); // unknown pre-release kind
+        assert!(!is_newer("0.1.0", "banana")); // garbage current version: no update either
+    }
+
+    #[test]
+    fn parses_tag_from_curl_headers() {
+        let ok = "HTTP/2 302\r\ncontent-length: 0\r\nlocation: https://github.com/SusieeTheLinuxUser/rig-hub/releases/tag/v0.1.0-alpha.4\r\n\r\n";
+        assert_eq!(latest_tag(ok), Some("0.1.0-alpha.4"));
+        assert_eq!(latest_tag(""), None); // empty output (offline, curl missing)
+        assert_eq!(latest_tag("HTTP/2 404\r\ncontent-length: 0\r\n\r\n"), None);
+        assert_eq!(latest_tag("location: https://github.com/x/y/releases/tag/banana\r\n"), None);
+    }
+}
+
 #[cfg(all(test, unix))]
 mod tests {
     #[test]

src/workers.rs

@@ -112,6 +112,8 @@ pub struct State {
     pub mic: Dev<Mic>,
     pub busy: Option<&'static str>,
     pub toast: Option<Toast>,
+    /// newest release tag, when GitHub has one this build doesn't (checked once at startup)
+    pub update: Option<String>,
 }
 
 pub type Shared = Arc<Mutex<State>>;
@@ -199,12 +201,41 @@ pub fn spawn(st: Shared, ctx: Context) -> Workers {
         std::thread::Builder::new().name(name.into()).spawn(move || f(st, ctx, rx)).unwrap();
         tx
     }
+    let cooler = go("cooler", &st, &ctx, cooler);
+    #[cfg(target_os = "linux")]
+    let mouse = go("mouse", &st, &ctx, mouse);
+    let headset = go("headset", &st, &ctx, headset);
+    let mic = go("mic", &st, &ctx, mic);
+    // one shot at startup; silent on any failure (curl missing, offline, odd output)
+    {
+        let (st, ctx) = (st.clone(), ctx.clone());
+        let _ = std::thread::Builder::new().name("update".into()).spawn(move || check_update(st, ctx));
+    }
     Workers {
-        cooler: go("cooler", &st, &ctx, cooler),
+        cooler,
         #[cfg(target_os = "linux")]
-        mouse: go("mouse", &st, &ctx, mouse),
-        headset: go("headset", &st, &ctx, headset),
-        mic: go("mic", &st, &ctx, mic),
+        mouse,
+        headset,
+        mic,
+    }
+}
+
+/// Ask GitHub where /releases/latest redirects and compare that tag with this build. No HTTP
+/// client here: curl ships with Linux and Windows 10+. Not the API — it allows 60 req/hour.
+fn check_update(st: Shared, ctx: Context) {
+    let mut curl = std::process::Command::new("curl");
+    curl.args(["-sSI", "--max-time", "10"]).arg(format!("{}/releases/latest", crate::REPO));
+    // Rig Hub has no console on Windows, so a console child would flash a black window.
+    #[cfg(windows)]
+    std::os::windows::process::CommandExt::creation_flags(&mut curl, 0x0800_0000); // CREATE_NO_WINDOW
+    let Ok(out) = curl.output() else {
+        return;
+    };
+    let headers = String::from_utf8_lossy(&out.stdout);
+    let Some(tag) = crate::latest_tag(&headers) else { return };
+    if crate::is_newer(tag, env!("CARGO_PKG_VERSION")) {
+        let tag = tag.to_string();
+        update(&st, &ctx, |s| s.update = Some(tag));
     }
 }