refactoring

Resolve #7779

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

@@ -0,0 +1,25 @@
+// AID
+// 長さ8の[2000年1月1日からの経過ミリ秒をbase36でエンコードしたもの] + 長さ2の[ノイズ文字列]
+
+import * as crypto from 'crypto';
+
+const TIME2000 = 946684800000;
+let counter = crypto.randomBytes(2).readUInt16LE(0);
+
+function getTime(time: number) {
+	time = time - TIME2000;
+	if (time < 0) time = 0;
+
+	return time.toString(36).padStart(8, '0');
+}
+
+function getNoise() {
+	return counter.toString(36).padStart(2, '0').slice(-2);
+}
+
+export function genAid(date: Date): string {
+	const t = date.getTime();
+	if (isNaN(t)) throw 'Failed to create AID: Invalid Date';
+	counter++;
+	return getTime(t) + getNoise();
+}