import type { ConversionJobView } from '@dorfteich/shared';

import { ApiError, apiGet } from '../lib/api';

const POLL_INTERVAL_MS = 1000;
/** Default poll budget — a whole-account export (#68) can take longer than a
 * single-page conversion, so callers may raise or lower it. */
const DEFAULT_MAX_POLLS = 300;

const delay = (ms: number): Promise<void> => new Promise((resolve) => setTimeout(resolve, ms));

/** Poll a conversion job until it succeeds or fails, or the poll budget runs
 * out (returns whatever the last status was). Shared by every export hook. */
export async function pollJob(
  job: ConversionJobView,
  maxPolls = DEFAULT_MAX_POLLS,
): Promise<ConversionJobView> {
  let current = job;
  for (
    let poll = 0;
    current.status !== 'succeeded' && current.status !== 'failed' && poll < maxPolls;
    poll += 1
  ) {
    await delay(POLL_INTERVAL_MS);
    current = await apiGet<ConversionJobView>(`/jobs/${current.id}`);
  }
  return current;
}

/** Download a finished job's result and save it as `fileName`. The result
 * endpoint is session-authenticated, so a plain `fetch` carries the cookie. */
export async function downloadJobResult(jobId: string, fileName: string): Promise<void> {
  const response = await fetch(`/api/v1/jobs/${jobId}/result`);
  if (!response.ok) {
    throw new ApiError(response.status, { code: `http_${response.status}`, message: '' });
  }
  const blob = await response.blob();
  const url = URL.createObjectURL(blob);
  const anchor = document.createElement('a');
  anchor.href = url;
  anchor.download = fileName;
  document.body.appendChild(anchor);
  anchor.click();
  anchor.remove();
  URL.revokeObjectURL(url);
}