refactoring

Resolve #7779

packages/backend/src/misc/id/meid.ts

@@ -0,0 +1,26 @@
+const CHARS = '0123456789abcdef';
+
+function getTime(time: number) {
+	if (time < 0) time = 0;
+	if (time === 0) {
+		return CHARS[0];
+	}
+
+	time += 0x800000000000;
+
+	return time.toString(16).padStart(12, CHARS[0]);
+}
+
+function getRandom() {
+	let str = '';
+
+	for (let i = 0; i < 12; i++) {
+		str += CHARS[Math.floor(Math.random() * CHARS.length)];
+	}
+
+	return str;
+}
+
+export function genMeid(date: Date): string {
+	return getTime(date.getTime()) + getRandom();
+}