calendar

import * as ical from "node-ical";

export interface CalEvent {
  uid: string;
  summary: string;
  start: Date;
  end: Date;
  location?: string;
  description?: string;
  allDay: boolean;
}

export async function parseIcsFile(filePath: string): Promise<CalEvent[]> {
  const raw = await ical.async.parseFile(filePath);
  const events: CalEvent[] = [];

  for (const key of Object.keys(raw)) {
    const item = raw[key];
    if (item.type !== "VEVENT") continue;

    const start = item.start instanceof Date ? item.start : new Date(item.start as string);
    const end = item.end instanceof Date ? item.end : new Date(item.end as string);

    events.push({
      uid: item.uid ?? key,
      summary: item.summary ?? "(no title)",
      start,
      end,
      location: item.location,
      description: item.description,
      allDay: (item as unknown as Record<string, unknown>).datetype === "date",
    });
  }

  return events.sort((a, b) => a.start.getTime() - b.start.getTime());
}

export function filterByRange(events: CalEvent[], from: Date, to: Date): CalEvent[] {
  return events.filter(e => e.end >= from && e.start <= to);
}

export function formatEvent(e: CalEvent): string {
  const time = e.allDay
    ? "all-day"
    : `${e.start.toLocaleTimeString([], { hour: "2-digit", minute: "2-digit" })}–${e.end.toLocaleTimeString([], { hour: "2-digit", minute: "2-digit" })}`;
  const loc = e.location ? ` @ ${e.location}` : "";
  return `${time}: ${e.summary}${loc}`;
}