import { API_URL } from "../config/api.ts";

/** Mirrors one entry of GET /api/youtube/playlist. */
export interface YouTubeTrack {
  videoId: string;
  title: string;
  /** Seconds. */
  duration?: number;
}

/**
 * The playlist an embed URL plays, if any.
 *
 * Covers both embed shapes the provider produces: `/embed/videoseries?list=…`
 * for a bare playlist, and `/embed/<id>?list=…` for a video opened in one.
 */
export function embedListId(embedUrl: string): string | null {
  try {
    return new URL(embedUrl).searchParams.get("list");
  } catch {
    return null;
  }
}

/**
 * Add the parameters the IFrame Player API needs to talk to the embed.
 *
 * `enablejsapi` has to be in the src the iframe was created with — it cannot be
 * turned on afterwards — so it is added for every playlist embed, whether or
 * not the API script ends up loading.
 */
export function withJsApi(url: string): string {
  try {
    const u = new URL(url);
    u.searchParams.set("enablejsapi", "1");
    u.searchParams.set("origin", globalThis.location.origin);
    return u.toString();
  } catch {
    return url;
  }
}

/** Titles and lengths for a playlist. Throws; callers fall back to no list. */
export async function fetchPlaylistTracks(
  listId: string,
): Promise<YouTubeTrack[]> {
  const res = await fetch(
    `${API_URL}/api/youtube/playlist?list=${encodeURIComponent(listId)}`,
  );
  if (!res.ok) throw new Error(`playlist fetch failed: ${res.status}`);
  const body = await res.json() as {
    success: boolean;
    data?: { tracks?: YouTubeTrack[] };
  };
  const tracks = body.data?.tracks;
  if (!body.success || !tracks?.length) throw new Error("no tracks");
  return tracks;
}