import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import { DateTime } from "luxon";
export function register(server: McpServer): void {
server.tool(
"countdown",
"Calculate a countdown from now to a target date/time. Returns remaining days, hours, minutes, seconds and whether the date is in the past.",
{
target: z.string().describe("Target date/time in ISO 8601 format (e.g. 2024-12-31T23:59:59 or 2025-01-01)"),
timezone: z.string().optional().describe("IANA timezone for the target date. Defaults to UTC."),
},
async ({ target, timezone }) => {
const tz = timezone || "UTC";
const now = DateTime.now().setZone(tz);
const targetDt = DateTime.fromISO(target, { zone: tz });
if (!targetDt.isValid) {
return { content: [{ type: "text", text: JSON.stringify({ error: `Invalid target date: ${targetDt.invalidExplanation}` }) }] };
}
const isPast = targetDt < now;
const [earlier, later] = isPast ? [targetDt, now] : [now, targetDt];
const diff = later.diff(earlier, ["days", "hours", "minutes", "seconds"]);
const result = {
now: now.toISO(),
target: targetDt.toISO(),
timezone: tz,
isPast,
remaining: {
days: Math.floor(diff.days),
hours: Math.floor(diff.hours),
minutes: Math.floor(diff.minutes),
seconds: Math.floor(diff.seconds),
},
totalDays: Math.floor(diff.as("days")),
totalHours: Math.floor(diff.as("hours")),
totalSeconds: Math.floor(diff.as("seconds")),
summary: isPast
? `${Math.floor(diff.as("days"))} days ago`
: `${Math.floor(diff.as("days"))} days remaining`,
};
return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] };
}
);
}
