1 files changed, 55 insertions, 0 deletions
diff --git a/src/app/game/game.utils.ts b/src/app/game/game.utils.ts
new file mode 100644
index 0000000..b2037e5
--- /dev/null
+++ b/src/app/game/game.utils.ts
@@ -0,0 +1,55 @@
+export interface GameLine {
+  millisecond: number;
+  content: string;
+}
+
+export function parseLrcLines(
+  lrcText: string,
+  options?: { skipBacking?: boolean }
+): GameLine[] {
+  const result: GameLine[] = [];
+  const lineRegex = /\[(\d{2,3}):(\d{2})\.(\d{2,3})\]/g;
+  const { skipBacking = false } = options ?? {};
+
+  for (const rawLine of lrcText.split("\n")) {
+    const timestamps: number[] = [];
+    let match: RegExpExecArray | null;
+    let lastIndex = 0;
+
+    lineRegex.lastIndex = 0;
+    while ((match = lineRegex.exec(rawLine)) !== null) {
+      const minutes = parseInt(match[1], 10);
+      const seconds = parseInt(match[2], 10);
+      const msField = match[3];
+      const ms =
+        msField.length === 2
+          ? parseInt(msField, 10) * 10
+          : parseInt(msField, 10);
+      timestamps.push(minutes * 60_000 + seconds * 1_000 + ms);
+      lastIndex = match.index + match[0].length;
+    }
+
+    if (timestamps.length === 0) continue;
+
+    const content = (skipBacking
+      ? rawLine.slice(lastIndex).replace(/\([^)]*\)/g, "")
+      : rawLine.slice(lastIndex)
+    ).trim();
+
+    for (const ms of timestamps) {
+      result.push({ millisecond: ms, content });
+    }
+  }
+
+  result.sort((a, b) => a.millisecond - b.millisecond);
+  return result;
+}
+
+export function calculateCPSNeeded(text: string, seconds: number): number {
+  return text.length / seconds;
+}
+
+export function formatTime(ms: number): string {
+  const s = Math.max(0, Math.floor(ms / 1000));
+  return `${Math.floor(s / 60)}:${String(s % 60).padStart(2, "0")}`;
+}