// ==UserScript==
// @name         Meta Tag Monitor
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Monitors meta tags for changes, location, and value
// @author       You
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function () {
  'use strict';

  let previousMetaData = new Map();

  const internalLog = (message) => {
    console.log(`META CHECK ✅: ${message}`);
  };

  function getMetaKey(meta) {
    return meta.getAttribute('name') || meta.getAttribute('property') || meta.getAttribute('charset') || meta.getAttribute('http-equiv') || 'unknown';
  }

  function getMetaValue(meta) {
    return meta.getAttribute('content') || meta.getAttribute('charset') || '';
  }

  function getLocation(meta) {
    return (document.head.contains(meta)) ? '🐵head🐵' : '🦾body🦾';
  }

  function scanMetaTags() {
    const metaTags = document.querySelectorAll('meta');
    const currentMetaData = new Map();

    metaTags.forEach(meta => {
      const key = getMetaKey(meta);
      const value = getMetaValue(meta);
      const location = getLocation(meta);
      const identifier = key + '|' + location;

      currentMetaData.set(identifier, value);

      if (!previousMetaData.has(identifier)) {
        internalLog(`[${key}](${location}) 📦 NEW 📦`);
      } else if (previousMetaData.get(identifier) !== value) {
        internalLog(`[${key}](${location}) 👷 UPDATED 👷`);
      }
    });

    // Check for deletions or movements
    previousMetaData.forEach((value, identifier) => {
      if (!currentMetaData.has(identifier)) {
        const [key, location] = identifier.split('|');
        const otherLocation = location === 'head' ? 'body' : 'head';
        const movedIdentifier = key + '|' + otherLocation;

        if (currentMetaData.has(movedIdentifier)) {
          internalLog(`[${key}](${location}) -> (${otherLocation}) 🛺 MOVED 🛺`);
        } else {
          internalLog(`[${key}](${location}) ❌ DELETED ❌`);
        }
      }
    });

    previousMetaData = currentMetaData;
  }

  function initialScan() {
    const metaTags = document.querySelectorAll('meta');
    metaTags.forEach(meta => {
      const key = getMetaKey(meta);
      const value = getMetaValue(meta);
      const location = getLocation(meta);
      const identifier = key + '|' + location;
      previousMetaData.set(identifier, value);
      internalLog(`[${key}](${location}) 📦 INITIAL 📦`);
    });
  }

  window.addEventListener('load', () => {
    initialScan();
    setInterval(scanMetaTags, 3000); // every 3 seconds
  });
})();