import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import { existsSync, readFileSync, writeFileSync, mkdirSync } from "fs";
import { join, dirname } from "path";
import { DateTime } from "luxon";
interface CountdownItem {
id: string;
name: string;
targetDate: string; // ISO 8601
timezone: string;
createdAt: string;
}
function getFilePath(dataDir: string): string {
return join(dataDir, "countdown.json");
}
function loadCountdowns(dataDir: string): CountdownItem[] {
const file = getFilePath(dataDir);
if (!existsSync(file)) return [];
try {
return JSON.parse(readFileSync(file, "utf-8")) as CountdownItem[];
} catch {
return [];
}
}
function saveCountdowns(dataDir: string, items: CountdownItem[]): void {
const file = getFilePath(dataDir);
mkdirSync(dirname(file), { recursive: true });
writeFileSync(file, JSON.stringify(items, null, 2), "utf-8");
}
export function register(server: McpServer, dataDir: string): void {
server.tool(
"manage_countdown",
"Manage persistent countdown timers. Supports CRUD operations: set (create), get (read one), list (read all), delete.",
{
action: z.enum(["set", "get", "list", "delete"]).describe("Action to perform"),
id: z.string().optional().describe("Countdown ID (required for get/delete, auto-generated for set if not provided)"),
name: z.string().optional().describe("Name/description for the countdown (required for set)"),
target_date: z.string().optional().describe("Target date in ISO 8601 format (required for set)"),
timezone: z.string().optional().describe("IANA timezone. Defaults to UTC."),
},
async ({ action, id, name, target_date, timezone }) => {
const tz = timezone || "UTC";
try {
if (action === "set") {
if (!name) return { content: [{ type: "text", text: JSON.stringify({ error: "name is required for set action" }) }] };
if (!target_date) return { content: [{ type: "text", text: JSON.stringify({ error: "target_date is required for set action" }) }] };
const targetDt = DateTime.fromISO(target_date, { zone: tz });
if (!targetDt.isValid) {
return { content: [{ type: "text", text: JSON.stringify({ error: `Invalid target_date: ${targetDt.invalidExplanation}` }) }] };
}
const items = loadCountdowns(dataDir);
const newItem: CountdownItem = {
id: id || `cd_${Date.now().toString(36)}`,
name,
targetDate: targetDt.toISO()!,
timezone: tz,
createdAt: DateTime.now().toISO()!,
};
// Replace if same ID exists
const existingIdx = items.findIndex(i => i.id === newItem.id);
if (existingIdx >= 0) {
items[existingIdx] = newItem;
} else {
items.push(newItem);
}
saveCountdowns(dataDir, items);
return { content: [{ type: "text", text: JSON.stringify({ success: true, item: newItem }, null, 2) }] };
}
if (action === "get") {
if (!id) return { content: [{ type: "text", text: JSON.stringify({ error: "id is required for get action" }) }] };
const items = loadCountdowns(dataDir);
const item = items.find(i => i.id === id);
if (!item) return { content: [{ type: "text", text: JSON.stringify({ error: `Countdown not found: ${id}` }) }] };
const now = DateTime.now().setZone(item.timezone);
const targetDt = DateTime.fromISO(item.targetDate, { zone: item.timezone });
const isPast = targetDt < now;
const [earlier, later] = isPast ? [targetDt, now] : [now, targetDt];
const diff = later.diff(earlier, ["days", "hours", "minutes", "seconds"]);
return {
content: [{
type: "text",
text: JSON.stringify({
...item,
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")),
}, null, 2),
}],
};
}
if (action === "list") {
const items = loadCountdowns(dataDir);
const now = DateTime.now();
const enriched = items.map(item => {
const targetDt = DateTime.fromISO(item.targetDate, { zone: item.timezone });
const isPast = targetDt < now;
const totalDays = Math.floor(Math.abs(targetDt.diff(now, "days").days));
return { ...item, isPast, totalDays };
});
return { content: [{ type: "text", text: JSON.stringify({ count: enriched.length, items: enriched }, null, 2) }] };
}
if (action === "delete") {
if (!id) return { content: [{ type: "text", text: JSON.stringify({ error: "id is required for delete action" }) }] };
const items = loadCountdowns(dataDir);
const idx = items.findIndex(i => i.id === id);
if (idx < 0) return { content: [{ type: "text", text: JSON.stringify({ error: `Countdown not found: ${id}` }) }] };
const removed = items.splice(idx, 1)[0];
saveCountdowns(dataDir, items);
return { content: [{ type: "text", text: JSON.stringify({ success: true, deleted: removed }, null, 2) }] };
}
return { content: [{ type: "text", text: JSON.stringify({ error: `Unknown action: ${action}` }) }] };
} catch (e: any) {
return { content: [{ type: "text", text: JSON.stringify({ error: e.message || String(e) }) }] };
}
}
);
}
