feat: support adaptive traffic units and precise quotas

vite-frontend/src/utils/traffic.ts

@@ -0,0 +1,72 @@
+export type TrafficUnit = "MB" | "GB" | "TB" | "PB";
+
+export const MIB = 1024 * 1024;
+export const GIB = 1024 * MIB;
+
+export const TRAFFIC_UNIT_MIB: Record<TrafficUnit, number> = {
+  MB: 1,
+  GB: 1024,
+  TB: 1024 ** 2,
+  PB: 1024 ** 3,
+};
+
+const BYTE_UNITS = ["B", "KB", "MB", "GB", "TB", "PB"];
+
+export function formatTraffic(bytes: number): string {
+  if (!Number.isFinite(bytes) || bytes <= 0) return "0 B";
+
+  let value = bytes;
+  let unit = 0;
+
+  while (value >= 1024 && unit < BYTE_UNITS.length - 1) {
+    value /= 1024;
+    unit++;
+  }
+
+  return `${unit === 0 ? Math.floor(value) : value.toFixed(2)} ${BYTE_UNITS[unit]}`;
+}
+
+export function flowLimitMiB(flowGB: number, flowMiB?: number): number {
+  return flowMiB && flowMiB > 0 ? flowMiB : flowGB * 1024;
+}
+
+export function flowLimitBytes(flowGB: number, flowMiB?: number): number {
+  return flowLimitMiB(flowGB, flowMiB) * MIB;
+}
+
+export function formatFlowLimit(flowGB: number, flowMiB?: number): string {
+  if (flowGB === 99999 && !flowMiB) return "无限制";
+
+  return formatTraffic(flowLimitBytes(flowGB, flowMiB));
+}
+
+export function preferredTrafficUnit(mib: number): TrafficUnit {
+  if (mib <= 0) return "GB";
+  if (mib > 0 && mib % TRAFFIC_UNIT_MIB.PB === 0) return "PB";
+  if (mib > 0 && mib % TRAFFIC_UNIT_MIB.TB === 0) return "TB";
+  if (mib > 0 && mib % TRAFFIC_UNIT_MIB.GB === 0) return "GB";
+
+  return "MB";
+}
+
+export function parseTrafficInput(
+  value: string,
+  unit: TrafficUnit,
+): number | null {
+  const amount = Number(value);
+  const mib = amount * TRAFFIC_UNIT_MIB[unit];
+
+  if (
+    !value.trim() ||
+    !Number.isFinite(amount) ||
+    amount <= 0 ||
+    !Number.isSafeInteger(mib)
+  ) {
+    return null;
+  }
+
+  // Backend stores bytes as int64. Keep the converted value within that range.
+  if (mib > 8_796_093_022_207) return null;
+
+  return mib;
+}