Phase7

packages/metering/src/index.ts

@@ -0,0 +1,48 @@
+/** Credits charged for RAM usage: 1 credit per GB-minute (rounded up). */
+export function calculateUsageCredits(ramMb: number, durationSeconds: number): number {
+  if (ramMb <= 0 || durationSeconds <= 0) {
+    return 0;
+  }
+
+  const gbMinutes = (ramMb / 1024) * (durationSeconds / 60);
+  return Math.max(1, Math.ceil(gbMinutes));
+}
+
+export function parseMinecraftListOutput(output: string): number {
+  const headerMatch = output.match(
+    /There are (\d+) of a max(?:imum)? of \d+ players? online/i,
+  );
+
+  if (headerMatch?.[1]) {
+    return Number.parseInt(headerMatch[1], 10);
+  }
+
+  const legacyMatch = output.match(/^(\d+) players? online/i);
+  if (legacyMatch?.[1]) {
+    return Number.parseInt(legacyMatch[1], 10);
+  }
+
+  return 0;
+}
+
+export interface IdlePolicy {
+  idleTimeoutMinutes: number;
+  idleGraceAfterStartMinutes: number;
+  idleCountdownSeconds: number;
+}
+
+export const DEFAULT_IDLE_POLICY: IdlePolicy = {
+  idleTimeoutMinutes: 15,
+  idleGraceAfterStartMinutes: 3,
+  idleCountdownSeconds: 120,
+};
+
+export function resolveIdlePolicy(plan?: Partial<IdlePolicy> | null): IdlePolicy {
+  return {
+    idleTimeoutMinutes: plan?.idleTimeoutMinutes ?? DEFAULT_IDLE_POLICY.idleTimeoutMinutes,
+    idleGraceAfterStartMinutes:
+      plan?.idleGraceAfterStartMinutes ?? DEFAULT_IDLE_POLICY.idleGraceAfterStartMinutes,
+    idleCountdownSeconds:
+      plan?.idleCountdownSeconds ?? DEFAULT_IDLE_POLICY.idleCountdownSeconds,
+  };
+}

packages/metering/src/metering.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  calculateUsageCredits,
+  parseMinecraftListOutput,
+} from './index';
+
+describe('metering', () => {
+  it('charges credits by RAM-GB-minutes', () => {
+    expect(calculateUsageCredits(1024, 60)).toBe(1);
+    expect(calculateUsageCredits(2048, 60)).toBe(2);
+    expect(calculateUsageCredits(512, 30)).toBe(1);
+  });
+
+  it('parses minecraft list command output', () => {
+    expect(
+      parseMinecraftListOutput('There are 2 of a max of 20 players online: Steve, Alex'),
+    ).toBe(2);
+    expect(
+      parseMinecraftListOutput('There are 0 of a maximum of 10 players online:'),
+    ).toBe(0);
+  });
+});