refactoring

Resolve #7779

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

@@ -0,0 +1,28 @@
+const CHARS = '0123456789abcdef';
+
+//  4bit Fixed hex value 'g'
+// 44bit UNIX Time ms in Hex
+// 48bit Random value in Hex
+
+function getTime(time: number) {
+	if (time < 0) time = 0;
+	if (time === 0) {
+		return CHARS[0];
+	}
+
+	return time.toString(16).padStart(11, 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 genMeidg(date: Date): string {
+	return 'g' + getTime(date.getTime()) + getRandom();
+}