let whitelist = [];
let whitelistHandles = [];
let debugEnabled = false;
const memberOnlyIndex = new Map();
const DATA_PREFIX = "chipperfluff-nobs";

/* ---------------- CSS injection ---------------- */

function injectStyleOnce() {
  if (document.getElementById("member-filter-style")) return;

  const style = document.createElement("style");
  style.id = "member-filter-style";
  style.textContent = `
    [data-${DATA_PREFIX}-hidden="true"] {
      display: none !important;
    }
  `;
  document.head.appendChild(style);
}

injectStyleOnce();

/* ---------------- load whitelist ---------------- */

function debugLog(...args) {
  if (!debugEnabled) return;
  console.log("[MemberFilter]", ...args);
}

function debugGroup(...args) {
  if (!debugEnabled) return;
  console.group("[MemberFilter]", ...args);
}

function debugGroupEnd() {
  if (!debugEnabled) return;
  console.groupEnd();
}

function normalizeKey(value) {
  return value
    .toLowerCase()
    .replace(/\u00a0/g, " ")
    .replace(/\s+/g, " ")
    .replace(/\u2022/g, "")
    .trim();
}

function normalizeWhitelist(list) {
  const names = [];
  const handles = [];
  (list || []).forEach(item => {
    if (typeof item === "string") {
      if (item) names.push(normalizeKey(item));
      return;
    }
    const name = normalizeKey(item.name || "");
    const handle = normalizeKey(item.handle || "");
    if (name) names.push(name);
    if (handle) handles.push(handle);
  });
  return { names, handles };
}

function loadSettings() {
  chrome.storage.local.get({ whitelist: [], debug: false }, data => {
    const { names, handles } = normalizeWhitelist(data.whitelist);
    whitelist = names;
    whitelistHandles = handles;
    debugEnabled = Boolean(data.debug);
    debugLog("settings loaded:", { whitelist, whitelistHandles, debugEnabled });
    if (isWhitelistedChannelPage()) {
      revealAll();
      return;
    }
    updateKnownVisibility();
    process();
  });
}

loadSettings();

// Reload settings if popup changes them
chrome.storage.onChanged.addListener(loadSettings);

/* ---------------- detection logic ---------------- */

function process(root = document) {
  if (isWhitelistedChannelPage()) return;
  const badges = root.querySelectorAll("badge-shape");

  badges.forEach(badge => {
    if (!badge.textContent?.includes("Nur für Kanalmitglieder")) return;

    const video = badge.closest(
      "ytd-rich-item-renderer, ytd-video-renderer, ytd-grid-video-renderer"
    );

    if (!video) return;

    const titleEl = video.querySelector("#video-title");
    const channelEl =
      video.querySelector("ytd-channel-name a") ||
      video.querySelector(".ytd-channel-name a");

    const title = titleEl?.textContent?.trim() ?? "(no title)";
    const url = titleEl?.href ?? "";
    const channel = channelEl?.textContent?.trim() ?? "(no channel)";
    const channelKey = normalizeKey(channel);
    const id = getVideoId(video, url);

    video.setAttribute(`data-${DATA_PREFIX}-member-only`, "true");
    if (channelKey) video.setAttribute(`data-${DATA_PREFIX}-channel`, channelKey);
    if (id) video.setAttribute(`data-${DATA_PREFIX}-id`, id);

    if (id) {
      memberOnlyIndex.set(id, { channelKey, hidden: false });
    }

    const whitelisted = whitelist.includes(channelKey);

    debugGroup();
    debugLog("Title  :", title);
    debugLog("Channel:", channel);
    debugLog("URL    :", url);
    debugLog("ID     :", id || "(no id)");
    debugLog("Whitelisted:", whitelisted);
    debugGroupEnd();

    if (!whitelisted) {
      video.setAttribute(`data-${DATA_PREFIX}-hidden`, "true");
      if (id && memberOnlyIndex.has(id)) {
        memberOnlyIndex.get(id).hidden = true;
      }
    } else {
      video.removeAttribute(`data-${DATA_PREFIX}-hidden`);
      if (id && memberOnlyIndex.has(id)) {
        memberOnlyIndex.get(id).hidden = false;
      }
    }
  });
}

function updateKnownVisibility() {
  if (isWhitelistedChannelPage()) {
    revealAll();
    return;
  }
  for (const [id, meta] of memberOnlyIndex.entries()) {
    if (!meta.channelKey) continue;
    const video = findVideoById(id);
    if (!video) {
      memberOnlyIndex.delete(id);
      continue;
    }
    if (whitelist.includes(meta.channelKey)) {
      video.removeAttribute(`data-${DATA_PREFIX}-hidden`);
      meta.hidden = false;
    } else {
      video.setAttribute(`data-${DATA_PREFIX}-hidden`, "true");
      meta.hidden = true;
    }
  }
}

function isWhitelistedChannelPage() {
  const handle = getChannelHandleFromUrl(location.href);
  if (!handle) return false;
  return whitelistHandles.includes(normalizeKey(handle));
}

function getChannelHandleFromUrl(url) {
  const match = url.match(/youtube\.com\/@([^/]+)/i);
  return match ? match[1] : "";
}

function revealAll() {
  const videos = document.querySelectorAll(
    `[data-${DATA_PREFIX}-hidden="true"]`
  );
  videos.forEach(video => video.removeAttribute(`data-${DATA_PREFIX}-hidden`));
}

function getVideoId(video, url) {
  const dataId = video.getAttribute("data-video-id");
  if (dataId) return dataId;
  if (url) return url;
  const fallbackId = video.id;
  return fallbackId || "";
}

function getChannelKey(video) {
  const stored = video.getAttribute(`data-${DATA_PREFIX}-channel`);
  if (stored) return stored;

  const channelEl =
    video.querySelector("ytd-channel-name a") ||
    video.querySelector(".ytd-channel-name a");
  const channel = channelEl?.textContent?.trim() ?? "";
  return channel ? normalizeKey(channel) : "";
}

function findVideoById(id) {
  const escaped = cssEscape(id);
  return document.querySelector(`[data-${DATA_PREFIX}-id="${escaped}"]`);
}

function cssEscape(value) {
  if (window.CSS && CSS.escape) return CSS.escape(value);
  return String(value).replace(/["\\]/g, "\\$&");
}

/* ---------------- initial + observer ---------------- */

process();

const observer = new MutationObserver(mutations => {
  for (const m of mutations) {
    for (const node of m.addedNodes) {
      if (node instanceof HTMLElement) {
        process(node);
      }
    }
  }
});

observer.observe(document.body, {
  childList: true,
  subtree: true
});