import type { Payload } from "payload";
import type { BookingRequest, Customer, Event, Offer } from "@/payload-types";

export type AdminCalendarItem = {
  id: string;
  kind: "booking" | "event";
  title: string;
  subtitle?: string;
  date: string;
  startTime: string;
  endTime: string;
  status: string; // booking status, or "public" for a standalone Event
  appointmentType?: "onsite" | "online";
  href: string;
};

/**
 * Combines private BookingRequests with standalone public Events (excluding
 * the auto-generated Events already represented by a confirmed online
 * booking, so Anna never sees the same appointment listed twice) into one
 * unified calendar feed for the admin view.
 */
export async function getAdminCalendarItems(
  payload: Payload,
  range: { from: Date; to: Date },
): Promise<AdminCalendarItem[]> {
  const fromISO = range.from.toISOString();
  const toISO = range.to.toISOString();

  const [{ docs: bookings }, { docs: events }] = await Promise.all([
    payload.find({
      collection: "booking-requests",
      where: { and: [{ date: { greater_than_equal: fromISO } }, { date: { less_than_equal: toISO } }] },
      depth: 2,
      limit: 500,
    }),
    payload.find({
      collection: "events",
      where: {
        and: [
          { date: { greater_than_equal: fromISO } },
          { date: { less_than_equal: toISO } },
          { isPrivateBooking: { not_equals: true } },
        ],
      },
      depth: 0,
      limit: 500,
    }),
  ]);

  const bookingItems: AdminCalendarItem[] = (bookings as BookingRequest[]).map((b) => {
    const offer = typeof b.offer === "object" ? (b.offer as Offer) : null;
    const customer = typeof b.user === "object" ? (b.user as Customer) : null;
    return {
      id: `booking-${b.id}`,
      kind: "booking",
      title: offer?.title ?? "Buchung",
      subtitle: customer?.name,
      date: b.date,
      startTime: b.startTime,
      endTime: b.endTime,
      status: b.status,
      appointmentType: b.appointmentType,
      href: `/admin/collections/booking-requests/${b.id}`,
    };
  });

  const eventItems: AdminCalendarItem[] = (events as Event[]).map((e) => ({
    id: `event-${e.id}`,
    kind: "event",
    title: e.title,
    date: e.date,
    startTime: e.startTime ?? e.date,
    endTime: e.endTime ?? e.date,
    status: "public",
    appointmentType: e.isOnline ? "online" : "onsite",
    href: `/admin/collections/events/${e.id}`,
  }));

  return [...bookingItems, ...eventItems].sort((a, b) => new Date(a.startTime).getTime() - new Date(b.startTime).getTime());
}