/**
 * @description Array of selectors
 * @type {string[]}
 */

let classes = [];

/**
 * @description Shortcut to send messages to background script
 * @type {void}
 */

const dispatch = chrome.runtime.sendMessage;

/**
 * @description Is consent preview page?
 */

const isConsentPreview = document.location.host.startsWith("consent.");

/**
 * @description Options provided to observer
 */

const options = { childList: true, subtree: true };

/**
 * @description Selectors list
 * @type {string}
 */

let selectors = "";

/**
 * @description Target provided to observer
 */

const target = document.body || document.documentElement;

/**
 * @description Cleans DOM
 */

const clean = () => {
  if (selectors.length) {
    const results = document.querySelectorAll(selectors);

    for (let i = results.length; i--; ) results[i].outerHTML = "";
  }
};

/**
 * @description Fixes scroll issues
 */

const fix = () => {
  const body = document.body;
  const facebook = document.getElementsByClassName("_31e")[0];
  const google = document.querySelector('form[action*="consent.google"]');
  const html = document.documentElement;
  const yahoo = document.querySelector("#consent-page");

  if (body) {
    if (classes.length) body.classList.remove(...classes);
    body.style.setProperty("overflow-y", "initial", "important");
    body.style.setProperty("position", "initial", "important");
  }

  if (facebook) {
    facebook.style.setProperty("position", "initial", "important");
  }

  if (google) {
    google.querySelector("button").click();
  }

  if (html) {
    if (classes.length) html.classList.remove(...classes);
    html.style.setProperty("position", "initial", "important");
    html.style.setProperty("overflow-y", "initial", "important");
  }

  if (yahoo) {
    yahoo.querySelector('button[type="submit"]').click();
  }
};

const observer = new MutationObserver((mutations, instance) => {
  instance.disconnect();
  fix();

  if (!isConsentPreview) {
    for (let i = mutations.length; i--; ) {
      const mutation = mutations[i];

      for (let j = mutation.addedNodes.length; j--; ) {
        const node = mutation.addedNodes[j];
        const valid =
          node instanceof HTMLElement &&
          node.parentElement &&
          !["BODY", "HTML"].includes(node.tagName);

        if (!valid) continue;

        if (node.matches(selectors)) node.outerHTML = "";
      }
    }
  }

  instance.observe(target, options);
});

/**
 * @description Setups classes selectors
 * @returns {Promise<{ classes: string[] }>}
 */

const setupClasses = () =>
  new Promise((resolve) => {
    dispatch({ type: "GET_CLASSES" }, null, resolve);
  });

/**
 * @description Setups elements selectors
 * @returns {Promise<{ selectors: string }>}
 */

const setupSelectors = () =>
  new Promise((resolve) => {
    dispatch({ type: "GET_SELECTORS" }, null, resolve);
  });

/**
 * @description Listens DOM complete state
 */

document.addEventListener("readystatechange", () => {
  if (document.readyState === "complete") {
    fix();

    if (!isConsentPreview) {
      clean();
      setTimeout(clean, 2000);
    }
  }
});

/**
 * @description Setups everything and starts to observe if enabled
 */

dispatch(
  { hostname: document.location.hostname, type: "GET_CACHE" },
  null,
  async ({ enabled }) => {
    dispatch({ type: "ENABLE_POPUP" });

    if (enabled) {
      dispatch({ type: "ENABLE_ICON" });
      const results = await Promise.all([setupClasses(), setupSelectors()]);
      classes = results[0].classes;
      selectors = results[1].selectors;
      observer.observe(target, options);
    }
  }
);