import { viewerMomentUrl } from "yt-dlp-transcript-common/lib/momentUrl";
import { ARCHIVE_ORIGIN, ARCHIVE_CHANNEL, LEAD_IN } from "../song/archive-url.mjs";

// A clip's source moment, in the public archive.
//
// WHERE comes from song/archive-url.mjs -- the same constants the three page
// generators use, so the app and the static pages can never point at different
// archives. HOW comes from common/lib/momentUrl.ts, which is the module that
// actually owns the viewer's `?v=&t=` scheme.
//
// The two agree exactly. viewerMomentUrl floors `t - LEAD_IN`; the generators
// compute `floor(t) - LEAD_IN`. Those are the same number for every real `t`
// because LEAD_IN is an integer. The one divergence is at the very start of an
// episode: viewerMomentUrl omits `t` entirely when it would be 0, where the
// generators emit `t=0`. The viewer treats both identically.

export { ARCHIVE_ORIGIN, ARCHIVE_CHANNEL, LEAD_IN };

/** The viewer deep link for a source moment, with the lead-in applied. */
export function archiveMomentUrl(video: string, srcStart: number): string | null {
  return viewerMomentUrl(ARCHIVE_ORIGIN, `${ARCHIVE_CHANNEL}/${video}`, srcStart - LEAD_IN);
}