yt-playlist-features/src/content/extractor.ts

import type {
  PlaylistData,
  PlaylistMetadata,
  PlaylistVideo,
  Thumbnail,
} from "../types/playlist";

/* eslint-disable @typescript-eslint/no-explicit-any */

export interface InitialParseResult {
  metadata: PlaylistMetadata;
  videos: PlaylistVideo[];
}

export function parseInitialData(raw: any): InitialParseResult | null {
  try {
    const metadata = extractMetadata(raw);
    if (!metadata) return null;

    const videoListContents = findVideoListContents(raw);
    if (!videoListContents) return null;

    const { videos } = parseVideoList(videoListContents);
    return { metadata, videos };
  } catch (e) {
    console.error("[yt-playlist-features] Failed to parse playlist data:", e);
    return null;
  }
}

export function buildPlaylistData(
  metadata: PlaylistMetadata,
  videos: PlaylistVideo[],
  isComplete: boolean,
): PlaylistData {
  return {
    metadata,
    videos,
    extractedAt: new Date().toISOString(),
    isComplete,
    extractedCount: videos.length,
  };
}

// --- internal helpers ---

function parseVideoList(contents: any[]): {
  videos: PlaylistVideo[];
} {
  const videos: PlaylistVideo[] = [];

  for (const item of contents) {
    if (item.playlistVideoRenderer) {
      const video = parseVideo(item.playlistVideoRenderer);
      if (video) videos.push(video);
    }
  }

  return { videos };
}

function extractMetadata(raw: any): PlaylistMetadata | null {
  const playlistId = extractPlaylistId(raw);
  if (!playlistId) return null;

  const metadataRenderer = raw?.metadata?.playlistMetadataRenderer;
  const title = metadataRenderer?.title ?? "";

  const sidebarItems =
    raw?.sidebar?.playlistSidebarRenderer?.items ?? [];
  const primaryInfo = sidebarItems[0]?.playlistSidebarPrimaryInfoRenderer;
  const secondaryInfo = sidebarItems[1]?.playlistSidebarSecondaryInfoRenderer;

  const stats = primaryInfo?.stats ?? [];
  const videoCount = parseVideoCount(stats[0]);
  const viewCountText = extractText(stats[1]) || null;
  const lastUpdatedText = extractText(stats[2]) || null;

  const pageHeaderVM =
    raw?.header?.pageHeaderRenderer?.content?.pageHeaderViewModel;
  const description =
    extractText(pageHeaderVM?.description?.descriptionPreviewViewModel?.description) ||
    extractText(primaryInfo?.description) ||
    "";

  const ownerRenderer =
    secondaryInfo?.videoOwner?.videoOwnerRenderer;
  const ownerRun = ownerRenderer?.title?.runs?.[0];
  const ownerEndpoint =
    ownerRun?.navigationEndpoint?.browseEndpoint;

  const thumbnails = extractPlaylistThumbnails(pageHeaderVM, primaryInfo);

  return {
    playlistId,
    title,
    description,
    videoCount,
    totalDurationText: null,
    viewCountText,
    lastUpdatedText,
    thumbnails,
    owner: {
      name: ownerRun?.text ?? "",
      channelId: ownerEndpoint?.browseId ?? "",
      url: ownerRun?.navigationEndpoint?.commandMetadata
        ?.webCommandMetadata?.url ?? "",
    },
    privacy: "unknown",
  };
}

function extractPlaylistId(raw: any): string | null {
  const microformat =
    raw?.microformat?.microformatDataRenderer?.urlCanonical;
  if (microformat) {
    const match = microformat.match(/[?&]list=([^&]+)/);
    if (match) return match[1];
  }
  const appLink =
    raw?.metadata?.playlistMetadataRenderer?.androidAppindexingLink;
  if (appLink) {
    const match = appLink.match(/[?&]list=([^&]+)/);
    if (match) return match[1];
  }
  const url = new URL(window.location.href);
  return url.searchParams.get("list");
}

function findVideoListContents(raw: any): any[] | null {
  const tabs =
    raw?.contents?.twoColumnBrowseResultsRenderer?.tabs;
  if (!tabs?.length) return null;

  const tabContent = tabs[0]?.tabRenderer?.content;
  const sectionContents =
    tabContent?.sectionListRenderer?.contents;
  if (!sectionContents?.length) return null;

  const itemSection =
    sectionContents[0]?.itemSectionRenderer?.contents;
  if (!itemSection?.length) return null;

  return itemSection[0]?.playlistVideoListRenderer?.contents ?? null;
}

function parseVideo(renderer: any): PlaylistVideo | null {
  const videoId = renderer.videoId;
  if (!videoId) return null;

  const bylineRun = renderer.shortBylineText?.runs?.[0];
  const bylineEndpoint =
    bylineRun?.navigationEndpoint?.browseEndpoint;

  const lengthSeconds = renderer.lengthSeconds
    ? parseInt(renderer.lengthSeconds, 10)
    : null;

  return {
    videoId,
    title: extractText(renderer.title),
    index: parseInt(extractText(renderer.index) || "0", 10),
    durationSeconds: lengthSeconds,
    durationText: extractText(renderer.lengthText) || null,
    thumbnails: renderer.thumbnail?.thumbnails ?? [],
    channel: {
      name: bylineRun?.text ?? "",
      channelId: bylineEndpoint?.browseId ?? "",
      url: bylineRun?.navigationEndpoint?.commandMetadata
        ?.webCommandMetadata?.url ?? "",
    },
    isPlayable: renderer.isPlayable !== false,
    isLive:
      renderer.badges?.some(
        (b: any) =>
          b.metadataBadgeRenderer?.style === "BADGE_STYLE_TYPE_LIVE_NOW",
      ) ?? false,
    viewCountText: null,
    publishedAt: null,
    category: null,
    addedBy: null,
    voteCount: null,
  };
}

function extractText(textObj: any): string {
  if (!textObj) return "";
  if (typeof textObj === "string") return textObj;
  if (textObj.simpleText) return textObj.simpleText;
  if (textObj.runs) {
    return textObj.runs.map((r: any) => r.text).join("");
  }
  if (textObj.content) return extractText(textObj.content);
  return "";
}

function extractPlaylistThumbnails(
  pageHeaderVM: any,
  primaryInfo: any,
): Thumbnail[] {
  const heroThumbnails =
    pageHeaderVM?.heroImage?.contentPreviewImageViewModel?.image?.sources;
  if (heroThumbnails?.length) {
    return heroThumbnails.map((t: any) => ({
      url: t.url ?? "",
      width: t.width ?? 0,
      height: t.height ?? 0,
    }));
  }
  return (
    primaryInfo?.thumbnailRenderer?.playlistVideoThumbnailRenderer?.thumbnail
      ?.thumbnails ??
    primaryInfo?.thumbnailRenderer?.playlistCustomThumbnailRenderer?.thumbnail
      ?.thumbnails ??
    []
  );
}

function parseVideoCount(textObj: any): number {
  const text = extractText(textObj);
  const match = text.replace(/,/g, "").match(/(\d+)/);
  return match ? parseInt(match[1], 10) : 0;
}