osu! goals: real play counts from my most-played list (weekly), BPM range from the .osu timing points

src/lib/game-tracker/osu-goals.ts

@@ -22,6 +22,21 @@ export const FAST_BPM = 200;
  * Streams in a .osu file: consecutive circles at most a 1/4 beat apart (5% slack) form a run.
  * Returns the longest run and the number of circles in runs of 5 or more.
  */
+/** BPM range from the uninherited timing points of an .osu file (null when there are none). */
+export function bpmRange(osu: string): { min: number; max: number } | null {
+	const start = osu.indexOf('[TimingPoints]');
+	if (start < 0) return null;
+	const rest = osu.slice(start + 14);
+	const end = rest.search(/^\[/m);
+	const bpms = (end < 0 ? rest : rest.slice(0, end))
+		.split(/\r?\n/)
+		.map((l) => l.trim().split(','))
+		.filter((p) => p.length >= 2 && Number(p[1]) > 0 && (p.length < 7 || p[6] !== '0'))
+		.map((p) => Math.round((60000 / Number(p[1])) * 10) / 10)
+		.filter((b) => Number.isFinite(b) && b > 0);
+	return bpms.length ? { min: Math.min(...bpms), max: Math.max(...bpms) } : null;
+}
+
 export function streamStats(osu: string): { longest: number; notes: number } {
 	const section = (name: string) => {
 		const start = osu.indexOf(`[${name}]`);