dj sets + lyrics: a mix that names its own tracks, and words pulled off the separated voice

src/lib/setlistScan.svelte.js

@@ -0,0 +1,101 @@
+// Background DJ-set listening. A scan OUTLIVES the import modal: starting a
+// listen closes the modal, progress rides a global chip above the player
+// bar, the app stays fully usable, and the finished draft waits on the chip
+// until it is reviewed or dismissed. One scan at a time — the backend's
+// cancel flag is global by design.
+import * as api from "./api.js";
+
+export const setlistScan = $state({
+    active: false,
+    mode: null, // "youtube" | "file"
+    label: "",
+    stage: null, // "tool" | "runtime" | "audio" | "decode" | "listen"
+    window: 0,
+    total: 0,
+    pct: null,
+    hit: null,
+    draft: null, // finished ImportDraft awaiting review
+    error: null,
+    wantsReview: false, // chip clicked; the Playlists view consumes this
+});
+
+let subscribed = false;
+function subscribe() {
+    if (subscribed) return;
+    subscribed = true;
+    api.onEvent("playlist:scan-progress", (p) => {
+        // A ready chip must not be mutated by stray late events.
+        if (!setlistScan.active || setlistScan.draft || !p?.stage) return;
+        setlistScan.stage = p.stage;
+        if (p.window != null) setlistScan.window = p.window;
+        if (p.total != null) setlistScan.total = p.total;
+        setlistScan.pct = p.pct ?? null;
+        if (p.hit != null) setlistScan.hit = p.hit;
+    });
+}
+
+async function run(mode, label, call) {
+    subscribe();
+    Object.assign(setlistScan, {
+        active: true,
+        mode,
+        label,
+        stage: mode === "youtube" ? "audio" : "decode",
+        window: 0,
+        total: 0,
+        pct: null,
+        hit: null,
+        draft: null,
+        error: null,
+        wantsReview: false,
+    });
+    try {
+        const draft = await call();
+        if (draft) {
+            setlistScan.draft = draft;
+            setlistScan.label = draft.name ?? label;
+        } else {
+            // Defensive: a null draft must not wedge the chip.
+            setlistScan.active = false;
+        }
+    } catch (e) {
+        const message = String(e);
+        if (message.includes("canceled")) setlistScan.active = false;
+        else setlistScan.error = message;
+    }
+}
+
+/** Kick a YouTube listen into the background. False = one already runs. */
+export function startYoutubeListen(url) {
+    if (setlistScan.active) return false;
+    void run("youtube", "YouTube set", () => api.playlistScanYoutube(url));
+    return true;
+}
+
+/** Listen to an already-picked set recording in the background, with an
+ *  optionally pasted tracklist riding along. False = one already runs. */
+export function startFileListen(path, tracklist = null, label = "Set recording") {
+    if (setlistScan.active) return false;
+    void run("file", label, () => api.playlistScanFile(path, tracklist));
+    return true;
+}
+
+/** Hand the finished draft to the review and clear the chip. */
+export function takeScanDraft() {
+    const draft = setlistScan.draft;
+    setlistScan.draft = null;
+    setlistScan.active = false;
+    setlistScan.wantsReview = false;
+    return draft;
+}
+
+/** Cancel a running scan, or drop a finished/failed one unseen. */
+export function dismissScan() {
+    if (setlistScan.active && !setlistScan.draft && !setlistScan.error) {
+        void api.playlistScanCancel();
+    }
+    setlistScan.active = false;
+    setlistScan.draft = null;
+    setlistScan.error = null;
+    setlistScan.wantsReview = false;
+}