Files
Moltbot/src/cron/schedule.ts
2026-02-21 20:18:11 -08:00

78 lines
2.5 KiB
TypeScript

import { Cron } from "croner";
import { parseAbsoluteTimeMs } from "./parse.js";
import type { CronSchedule } from "./types.js";
function resolveCronTimezone(tz?: string) {
const trimmed = typeof tz === "string" ? tz.trim() : "";
if (trimmed) {
return trimmed;
}
return Intl.DateTimeFormat().resolvedOptions().timeZone;
}
export function computeNextRunAtMs(schedule: CronSchedule, nowMs: number): number | undefined {
if (schedule.kind === "at") {
// Handle both canonical `at` (string) and legacy `atMs` (number) fields.
// The store migration should convert atMs→at, but be defensive in case
// the migration hasn't run yet or was bypassed.
const sched = schedule as { at?: string; atMs?: number | string };
const atMs =
typeof sched.atMs === "number" && Number.isFinite(sched.atMs) && sched.atMs > 0
? sched.atMs
: typeof sched.atMs === "string"
? parseAbsoluteTimeMs(sched.atMs)
: typeof sched.at === "string"
? parseAbsoluteTimeMs(sched.at)
: null;
if (atMs === null) {
return undefined;
}
return atMs > nowMs ? atMs : undefined;
}
if (schedule.kind === "every") {
const everyMs = Math.max(1, Math.floor(schedule.everyMs));
const anchor = Math.max(0, Math.floor(schedule.anchorMs ?? nowMs));
if (nowMs < anchor) {
return anchor;
}
const elapsed = nowMs - anchor;
const steps = Math.max(1, Math.floor((elapsed + everyMs - 1) / everyMs));
return anchor + steps * everyMs;
}
const exprSource = (schedule as { expr?: unknown }).expr;
if (typeof exprSource !== "string") {
throw new Error("invalid cron schedule: expr is required");
}
const expr = exprSource.trim();
if (!expr) {
return undefined;
}
const cron = new Cron(expr, {
timezone: resolveCronTimezone(schedule.tz),
catch: false,
});
const next = cron.nextRun(new Date(nowMs));
if (!next) {
return undefined;
}
const nextMs = next.getTime();
if (!Number.isFinite(nextMs)) {
return undefined;
}
if (nextMs > nowMs) {
return nextMs;
}
// Guard against same-second rescheduling loops: if croner returns
// "now" (or an earlier instant), retry from the next whole second.
const nextSecondMs = Math.floor(nowMs / 1000) * 1000 + 1000;
const retry = cron.nextRun(new Date(nextSecondMs));
if (!retry) {
return undefined;
}
const retryMs = retry.getTime();
return Number.isFinite(retryMs) && retryMs > nowMs ? retryMs : undefined;
}