import { getDeviceId } from '../lib/device';
import { fetchJson } from './apiClient';
import type { EventStats } from './eventApi';

const statsCache = new Map<string, { etag: string | null; data: EventStats }>();

export async function fetchEventStats(eventToken: string): Promise<EventStats> {
  const cached = statsCache.get(eventToken);
  const response = await fetchJson<{
    online_guests?: number;
    tasks_solved?: number;
    guest_count?: number;
    likes_count?: number;
    latest_photo_at?: string | null;
  }>(
    `/api/v1/events/${encodeURIComponent(eventToken)}/stats`,
    {
      headers: {
        'X-Device-Id': getDeviceId(),
      },
      etag: cached?.etag ?? null,
      noStore: true,
    }
  );

  if (response.notModified && cached) {
    return cached.data;
  }

  const stats: EventStats = {
    onlineGuests: response.data?.online_guests ?? 0,
    tasksSolved: response.data?.tasks_solved ?? 0,
    guestCount: response.data?.guest_count ?? 0,
    likesCount: response.data?.likes_count ?? 0,
    latestPhotoAt: response.data?.latest_photo_at ?? null,
  };

  statsCache.set(eventToken, { etag: response.etag, data: stats });
  return stats;
}

export function clearStatsCache(eventToken?: string) {
  if (eventToken) {
    statsCache.delete(eventToken);
    return;
  }
  statsCache.clear();
}