javascript:(function() {
  var textareas = document.querySelectorAll('textarea.input');
  textareas.forEach(function(textarea) {
    var text = textarea.value;


    var pattern1 = /$$\s*URL=(.*?)\s*\$\$(.*?)\s*\/\s*URL\s*$$/gi;
    var pattern2 = /$$\s*URL\s*\$\$(.*?)\s*\/\s*URL\s*$$/gi;
    replacedText = text.replace(pattern1, '[U][URL=$1]$2[/URL][/U]');
    replacedText = replacedText.replace(pattern2, '[U][URL]$1[/URL][/U]');
    replacedText = replacedText.replace(/$$U$$\$\$U\$\$URL=(.*?)\/URL\$\$\/U\$\$\/U$$/g, '[U][URL=$1[/URL][/U]');


    var existingUrlPattern = /(?<!\[U\])\[URL=(.*?)\](.*?)\[\/URL\](?!\[\/U\])/gi;
    replacedText = replacedText.replace(existingUrlPattern, '[U][URL=$1]$2[/URL][/U]');

    var existingUrlSimplePattern = /(?<!\[U\])\[URL\](.*?)\[\/URL\](?!\[\/U\])/gi;
    replacedText = replacedText.replace(existingUrlSimplePattern, '[U][URL]$1[/URL][/U]');

    var pattern3 = /(\n)([A-Z"]|\d|$$B$$|$$I$$|$$IMG$$)/g;
    var pattern6 = /($$HEADING=2$$|$$LIST$$|$$\*$$|$$\/LIST$$|$$IMG$$)/g;
    replacedText = replacedText.replace(pattern6, '\n$1');
    replacedText = replacedText.replace(/$$\/HEADING$$\n/g, '[/HEADING]\n');
    replacedText = replacedText.replace(/$$\/IMG$$\n/g, '[/IMG]\n');
    replacedText = replacedText.replace(/\[\/LIST\]/g, '[/LIST]\n');

    var pattern4 = /$$IMG alt="([^"]*)"/g;
    var pattern9 = /\$\$\/IMG$$([A-Za-z0-9])/g;
    replacedText = replacedText.replace(pattern4, '\n[IMG alt="$1"] ');
    replacedText = replacedText.replace(pattern9, '[/IMG] $1');

    var pattern5 = /\n/g;
    var pattern10 = /^\n+|\n{2,}|\n+$/g;
    replacedText = replacedText.replace(pattern5, '\n');
    replacedText = replacedText.replace(pattern10, '\n');

    var pattern7 = /$$\/?FONT(=.*?)?$$/g;
    var pattern8 = /$$\/?COLOR(=.*?)?$$/g;
    replacedText = replacedText.replace(pattern7, '');
    replacedText = replacedText.replace(pattern8, '');

    replacedText = replacedText.replace(/\$\$B\$\$(.*?)\$\$\/B\$\$/g, '[B]$1[/B]');
    replacedText = replacedText.replace(/\$\$I\$\$(.*?)\$\$\/I\$\$/g, '[I]$1[/I]');

    var mathPattern = /\$\$(.*?)\$\$/g;
    replacedText = replacedText.replace(mathPattern, '\$$$1\$$');

    var paragraphPattern = /([^\n])\n([A-Z0-9])/g;
    replacedText = replacedText.replace(paragraphPattern, '$1\n\n$2');

    var quotePattern = /$$QUOTE$$(?:.*?\n)*?(.*?)$$\/QUOTE$$/gs;
    replacedText = replacedText.replace(quotePattern, '[QUOTE][SIZE=4]$1[/SIZE][/QUOTE]');

    const emptyListItemsPattern = /\[LIST\](\n\[\*\]\s*)+\[\/LIST\]/gi;
    replacedText = replacedText.replace(emptyListItemsPattern, '');
    const emptyListBlockPattern = /\[LIST\]\s*\[\/LIST\]/gi;
    replacedText = replacedText.replace(emptyListBlockPattern, '');

    replacedText = replacedText.replace(/\[B\]\[\/B\]/g, '');
    replacedText = replacedText.replace(/\[I\]\[\/I\]/g, '');

    textarea.value = replacedText;
  });
})();