// BitChute records — the pure rules that are BitChute's own.
//
// A BitChute video is fetched by yt-dlp's BitChute extractor, which offers ONE
// format: the uploaded mp4, served as a plain file from a `seedNNN.bitchute.com`
// media host (`https://seed123.bitchute.com/<channel hash>/<id>.mp4`). That file
// is what the viewer plays: BitChute's embed (bitchute.com/embed/<id>/) takes
// no start time it honours, and a native <video> over the file seeks
// (common/components/FilePlayer.tsx), as archive.org records do.

type FormatLike = { url?: unknown; ext?: unknown; protocol?: unknown };

const MEDIA_HOST_RE = /^https:\/\/[a-z0-9-]+\.bitchute\.com\//i;
const PLAYABLE_EXT_RE = /\.(mp4|webm|m4v)(?:[?#]|$)/i;

function playable(url: unknown, ext: unknown, protocol?: unknown): url is string {
  if (typeof url !== "string" || !MEDIA_HOST_RE.test(url)) return false;
  // An HLS manifest carries ext "mp4" too; it is a playlist, not a file.
  if (/\.m3u8(?:[?#]|$)/i.test(url)) return false;
  if (typeof protocol === "string" && protocol.startsWith("m3u8")) return false;
  if (typeof ext === "string" && /^(mp4|webm|m4v)$/i.test(ext)) return true;
  return PLAYABLE_EXT_RE.test(url);
}

// The file a BitChute record's player plays: the first offered format that is
// a plain mp4/webm on a bitchute.com host, else the record's top-level `url`
// (yt-dlp writes the chosen format's there). An HLS manifest (a live stream)
// is not a file; undefined when there is none.
export function bitchutePlayableUrl(meta: {
  formats?: unknown;
  url?: unknown;
  ext?: unknown;
  protocol?: unknown;
}): string | undefined {
  const formats = Array.isArray(meta.formats) ? (meta.formats as FormatLike[]) : [];
  for (const f of formats) {
    if (f && playable(f.url, f.ext, f.protocol)) return f.url as string;
  }
  if (playable(meta.url, meta.ext, meta.protocol)) return meta.url as string;
  return undefined;
}