27 lines
904 B
TypeScript
27 lines
904 B
TypeScript
import { Cron } from "croner";
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import type { CronSchedule } from "./types.js";
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export function computeNextRunAtMs(schedule: CronSchedule, nowMs: number): number | undefined {
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if (schedule.kind === "at") {
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return schedule.atMs > nowMs ? schedule.atMs : undefined;
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}
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if (schedule.kind === "every") {
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const everyMs = Math.max(1, Math.floor(schedule.everyMs));
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const anchor = Math.max(0, Math.floor(schedule.anchorMs ?? nowMs));
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if (nowMs < anchor) return anchor;
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const elapsed = nowMs - anchor;
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const steps = Math.max(1, Math.floor((elapsed + everyMs - 1) / everyMs));
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return anchor + steps * everyMs;
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}
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const expr = schedule.expr.trim();
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if (!expr) return undefined;
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const cron = new Cron(expr, {
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timezone: schedule.tz?.trim() || undefined,
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catch: false,
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});
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const next = cron.nextRun(new Date(nowMs));
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return next ? next.getTime() : undefined;
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}
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