// Where a clip's source moment lives in the public archive.
//
// THIS IS THE CANONICAL DEFINITION. The same link was written out by hand in
// three separate generators -- build-um.mjs and the two pipeline/ page builders
// -- each of them embedding the origin, the channel slug and the lead-in as
// literal text inside a string of client JS. Three copies of a URL that has
// already been re-pointed once is three chances to re-point it incompletely.
//
// Plain JS with no dependencies on purpose: the generators are standalone
// scripts run from a bare `node`, and must stay that way. The app side
// (umtool/lib/archive.ts) imports these constants and builds the URL through
// common/lib/momentUrl.ts, so there is one definition of WHERE and one
// definition of HOW.

export const ARCHIVE_ORIGIN = process.env.ARCHIVE_ORIGIN ?? "https://jeralyzer.pages.dev";
export const ARCHIVE_CHANNEL = process.env.ARCHIVE_CHANNEL ?? "the-quartering";

// A DELIBERATE lead-in: land three seconds before the moment so the um is heard
// in context rather than starting mid-word. Removing it does not make the link
// more accurate, it makes it unusable -- you arrive after the thing you came
// to hear. Integer, which is what keeps floor(t) - LEAD_IN and floor(t -
// LEAD_IN) the same number.
export const LEAD_IN = 3;

/** `https://…/?v=the-quartering%2F` — append the video id, then `&t=`. */
export function archiveMomentBase() {
  return `${ARCHIVE_ORIGIN}/?v=${encodeURIComponent(`${ARCHIVE_CHANNEL}/`)}`;
}

/** The viewer deep link for a source moment, with the lead-in applied. */
export function archiveMomentUrl(video, seconds) {
  const t = Math.max(0, Math.floor(seconds) - LEAD_IN);
  return `${archiveMomentBase()}${video}&t=${t}`;
}