background.js

chrome.runtime.onInstalled.addListener(() => {
  chrome.storage.local.set({ hideOpponent: false });
});

chrome.storage.onChanged.addListener((changes, area) => {
  if (area === 'local' && changes.hideOpponent) {
    chrome.tabs.query({ active: true, currentWindow: true }, (tabs) => {
      if (tabs.length > 0) {
        const tab = tabs[0];
        if (tab.url.includes('lichess.org')) {
          chrome.scripting.executeScript({
            target: { tabId: tab.id },
            func: changes.hideOpponent.newValue ? hideOpponent : showOpponent
          });
        }
      }
    });
  }
});

function hideOpponent() {
  const playerinfo = document.querySelectorAll('.ruser-top');
  if (playerinfo.length) {
    const userLink = playerinfo[0].querySelector(".user-link");
    const rating = playerinfo[0].querySelector("rating");
    if (userLink) userLink.style.visibility = "hidden";
    if (rating) rating.style.visibility = "hidden";
  }

  const gameMetaPlayers = document.querySelectorAll('.game__meta__players');
  if (gameMetaPlayers.length) {
    const players = gameMetaPlayers[0].querySelectorAll(".user-link");
    players.forEach(player => {
      player.style.visibility = 'hidden';
    });
  }

  const crosstableUsers = document.querySelectorAll('.crosstable__users');
  if (crosstableUsers.length) {
    const players = crosstableUsers[0].querySelectorAll(".user-link");
    players[1].style.visibility = 'hidden';
  }
}

function showOpponent() {
  const playerinfo = document.querySelectorAll('.ruser-top');
  if (playerinfo.length) {
    const userLink = playerinfo[0].querySelector(".user-link");
    const rating = playerinfo[0].querySelector("rating");
    if (userLink) userLink.style.visibility = "";
    if (rating) rating.style.visibility = "";
  }

  const gameMetaPlayers = document.querySelectorAll('.game__meta__players');
  if (gameMetaPlayers.length) {
    const players = gameMetaPlayers[0].querySelectorAll(".user-link");
    players.forEach(player => {
      player.style.visibility = '';
    });
  }

  const crosstableUsers = document.querySelectorAll('.crosstable__users');
  if (crosstableUsers.length) {
    const players = crosstableUsers[0].querySelectorAll(".user-link");
    players[1].style.visibility = '';
  }
}