import type { NormalizedSchedule, Schedule, TimeUnit } from "./types.js";

const MIN_INTERVAL_MS = 60_000;
const MAX_INTERVAL_MS = 7 * 24 * 60 * 60_000;

export function parseSchedule(schedule: Schedule): NormalizedSchedule {
	if (schedule === "continuous" || schedule === "manual") return { type: schedule };

	const match = schedule.match(/^(\d+)(m|h|d)$/);
	if (!match?.[1] || !match[2]) {
		throw new Error(`Invalid schedule format: "${schedule}"`);
	}

	const value = Number.parseInt(match[1], 10);
	const multipliers: Record<TimeUnit, number> = {
		m: 60_000,
		h: 60 * 60_000,
		d: 24 * 60 * 60_000,
	};
	const intervalMs = value * multipliers[match[2] as TimeUnit];
	if (intervalMs < MIN_INTERVAL_MS)
		throw new Error("Schedule interval must be at least 1 minute");
	if (intervalMs > MAX_INTERVAL_MS) throw new Error("Schedule interval must be at most 7 days");
	return { type: "interval", intervalMs };
}