// ==UserScript==
// @name            Arca base64 autodecoder
// @name:ko         아카라이브 Base64 자동 디코더
// @version         1.206
// @author          Laria
// @match           https://arca.live/b/*/*
// @description     auto decode Base64 encoded link in Arca.live
// @description:ko  아카라이브 내 Base64로 인코딩된 링크를 자동으로 복호화합니다.
// @icon            https://www.google.com/s2/favicons?sz=64&domain=arca.live
// @license         MIT
// @encoding        utf-8
// @run-at          document-end
// @supportURL      https://greasyfork.org/ko/scripts/482577-arca-base64-autodecoder
// @namespace       https://greasyfork.org/users/1235854
// @grant           GM.getValue
// @grant           GM.setValue
// @grant           GM.deleteValue
// @grant           GM.registerMenuCommand
// @grant           GM.unregisterMenuCommand
// @grant           GM.setClipboard
// @downloadURL none
// ==/UserScript==

/*
 * == Change log ==
 * 1.0 - Release
 * 1.1 - Invalid character update (replace -> replaceAll)
 * 1.11 - Improved show multiple links
 * 1.12 - Show Single links Bugfix
 * 1.13 - Bugfix 1.12
 * 1.14 - Base64 add padding func
 * 1.15 - Add annotation, display improvements
 * 1.16 - Display improved - CSS applied
 * 1.17 - var safe, max_iter defined (~7, def:3)
 * 1.18 - auto update check, log system
 * 1.20 - add menu(base64 depth, user-drag auto decoding, hide encoded link, update notify)
 * 1.201 - base64 depth extends - 11, temporary disable - drag auto decoding
 * 1.202 - improve encoded link click callback, feature block in edit mode, enable drag auto decoding
 * 1.203 - add menu(restore defaults)
 * 1.204 - set update check interval -> 1day(86400), seperate localparameter
 * 1.205 - url chk add(write), code stabilization
 * 1.206 - add menu(expand menu), newline, encoded link copy function, show url hostname
*/

//base64 encoded(http:/*, https:/*) string prefix
const regexEncodedPrefixDef = [
    /(aHR0cDovL|aHR0cHM6Ly)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 1 time
    /(YUhSMGNEb3ZM|YUhSMGNITTZMe)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 2 time
    /(WVVoU01HTkViM1pN|WVVoU01HTklUVFpNZ)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 3 time
    /(V1ZWb1UwMUhUa1ZpTTFwT|V1ZWb1UwMUhUa2xVVkZwTl)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 4 time
    /(VjFaV2IxVXdNVWhVYTFacFRURndU|VjFaV2IxVXdNVWhVYTJ4VlZrWndUb)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 5 time
    /(VmpGYVYySXhWWGROVldoVllURmFjRlJVUm5kV|VmpGYVYySXhWWGROVldoVllUSjRWbFpyV25kVW)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 6 time
    /(Vm1wR1lWWXlTWGhXV0dST1ZsZG9WbGxVUm1GalJsSlZVbTVrV|Vm1wR1lWWXlTWGhXV0dST1ZsZG9WbGxVU2pSV2JGcHlWMjVrVl)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 7 time
    /(Vm0xd1IxbFdXWGxUV0doWFYwZFNUMVpzWkc5V2JHeFZVbTFHYWxKc1NsWlZiVFZyV|Vm0xd1IxbFdXWGxUV0doWFYwZFNUMVpzWkc5V2JHeFZVMnBTVjJKR2NIbFdNalZyVm)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 8 time
    /(Vm0weGQxSXhiRmRYV0d4VVYwZG9XRll3WkZOVU1WcHpXa2M1VjJKSGVGWlZiVEZIWVd4S2MxTnNXbFppVkZaeV|Vm0weGQxSXhiRmRYV0d4VVYwZG9XRll3WkZOVU1WcHpXa2M1VjJKSGVGWlZNbkJUVmpKS1IyTkliRmROYWxaeVZt)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 9 time
    /(Vm0wd2VHUXhTWGhpUm1SWVYwZDRWVll3Wkc5WFJsbDNXa1pPVlUxV2NIcFhhMk0xVmpKS1NHVkdXbFppVkVaSVdWZDRTMk14VG5OWGJGcHBWa1phZ|Vm0wd2VHUXhTWGhpUm1SWVYwZDRWVll3Wkc5WFJsbDNXa1pPVlUxV2NIcFhhMk0xVmpKS1NHVkdXbFpOYmtKVVZtcEtTMUl5VGtsaVJtUk9ZV3hhZVZad)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 10 time
    /(Vm0wd2QyVkhVWGhUV0docFVtMVNXVll3WkRSV1ZsbDNXa2M1V0ZKc2JETlhhMXBQVmxVeFYyTkljRmhoTWsweFZtcEtTMU5IVmtkWGJGcHBWa1ZhU1ZkV1pEUlRNazE0Vkc1T1dHSkdjSEJXYTFwaF|Vm0wd2QyVkhVWGhUV0docFVtMVNXVll3WkRSV1ZsbDNXa2M1V0ZKc2JETlhhMXBQVmxVeFYyTkljRmhoTWsweFZtcEtTMU5IVmtkWGJGcE9ZbXRLVlZadGNFdFRNVWw1Vkd0c2FWSnRVazlaVjNoaFpWWmFk)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //encoding 11 time
];

//TODO
const regexEncodedPrefixNewline1 = [
    /(Cmh0dHA6L|Cmh0dHBzOi8)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 1 time
    /(Q21oMGRIQTZM|Q21oMGRIQnpPaT)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 2 time
    /(UTIxb01HUklRVFpN|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 3 time
    /(VVRJeGIwMUhVa2xSVkZwT|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 4 time
    /(VlZSSmVHSXdNVWhWYTJ4U1ZrWndU|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 5 time
    /(VmxaU1NtVkhTWGROVldoV1lUSjRVMVpyV25kV|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 6 time
    /(Vm14YVUxTnRWa2hUV0dST1ZsZG9WMWxVU2pSVk1WcHlWMjVrV|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 7 time
    /(Vm0xNFlWVXhUblJXYTJoVVYwZFNUMVpzWkc5V01XeFZVMnBTVmsxV2NIbFdNalZyV|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 8 time
    /(Vm0weE5GbFdWWGhVYmxKWFlUSm9WVll3WkZOVU1WcHpXa2M1VjAxWGVGWlZNbkJUVm1zeFYyTkliRmROYWxaeV|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 9 time
    /(Vm0wd2VFNUdiRmRXV0doVllteEtXRmxVU205V1ZsbDNXa1pPVlUxV2NIcFhhMk0xVmpBeFdHVkdXbFpOYmtKVVZtMXplRll5VGtsaVJtUk9ZV3hhZV|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 10 time
    /(Vm0wd2QyVkZOVWRpUm1SWFYwZG9WbGx0ZUV0WFJteFZVMjA1VjFac2JETlhhMXBQVmxVeFYyTkljRmhoTWsweFZtcEJlRmRIVmtkWGJGcE9ZbXRLVlZadE1YcGxSbGw1Vkd0c2FWSnRVazlaVjNoaFpW|aaaa)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 newline, encoding 11 time
];

//TODO
const regexEncodedPrefixNewline2 = [
    /(CgpodHRwOi8|CgpodHRwczov)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 1 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 2 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 3 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 4 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 5 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 6 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 7 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 8 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 9 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 10 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 newline, encoding 11 time
];

//TODO
const regexEncodedPrefixSpace1 = [
    /(IGh0dHA6L|IGh0dHBzOi8)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 1 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 2 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 3 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 4 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 5 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 6 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 7 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 8 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 9 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 10 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 1 space, encoding 11 time
];

//TODO
const regexEncodedPrefixSpace2 = [
    /(ICBodHRwOi8|ICBodHRwczov)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 1 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 2 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 3 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 4 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 5 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 6 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 7 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 8 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 9 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 10 time
    /(|)(\w|=|\+|\/)*(?=[^\+=\w\/])/g, //with 2 space, encoding 11 time
];

//auto decoding maximum
const autoDecodingMaximum = Math.min(regexEncodedPrefixDef.length, regexEncodedPrefixNewline1.length, regexEncodedPrefixNewline2.length, regexEncodedPrefixSpace1.length, regexEncodedPrefixSpace2.length);

//regex prefix - drag
const regInvalid = /[^\w\+\/=]/;

//update check interval (sec, def:1 day(86400))
const updateInterval = 86400;

//update chk, fail->false
let updateAvailble = true;

//auto drag decoding enable status
let draggableActivated = false;

//encoded link list, [uuid]: [encoded link]
let encodedList = {};

//total decode count
let hindex = 0;

//drag function comparison
let lastSelected = document;
let lastSelectedTime = Date.now();

//domain - end chk
const deniedURLSuffix = ['/write', '/edit'];

//logging prefix, param
const logPromptDEF = '['+GM.info.script.name+']';
const logPromptUPD = '['+GM.info.script.name+'-UPD]';
const logPromptPARAM = '['+GM.info.script.name+'-PAR]';

//script local parameter
let localParameter = {
  'lastupdate': {
    'param_name': 'lastupdate',
    'value': 0,
    'def_value': 0,
  },
  'basedepth': {
    'param_name': 'basedepth',
    'value': 3,
    'def_value': 3,
  },
  'enclinkhide': {
    'param_name': 'enclinkhide',
    'value': false,
    'def_value': false,
  },
  'draggable': {
    'param_name': 'draggable',
    'value': false,
    'def_value': false,
  },
  'updatechk': {
    'param_name': 'chkupd',
    'value': true,
    'def_value': true,
  },
  'expandmenu': {
    'param_name': 'expandmenu',
    'value': true,
    'def_value': true,
  },
};

//script menu structure
let menuStructure = {
  'basedepth': {
    'param_name': localParameter.basedepth,
    'name': '🎛 base64 깊이 조절하기 - 현재 값 : 알수없음',
    'desc': '자동 base64 디코딩 깊이를 조절할 수 있습니다.',
    'id': -1,
    'func': menuFunctionBasedepth,
    'visible': true,
  },
  'enclinkhide': {
    'param_name': localParameter.enclinkhide,
    'name': '🔗 인코딩된 링크 [보이기/숨기기]',
    'desc': '자동 base64 디코딩 전 인코딩된 링크 표시 여부를 설정할 수 있습니다.',
    'id': -1,
    'func': menuFunctionEnchide,
    'visible': true,
  },
  'draggable': {
    'param_name': localParameter.draggable,
    'name': '🖱 드래그 시 자동 디코딩 [켜기/끄기]',
    'desc': '드래그 시 자동으로 드래그한 부분을 base64로 디코딩할지 설정할 수 있습니다.',
    'id': -1,
    'func': menuFunctionDraggable,
    'visible': true,
  },
  'updatechk': {
    'param_name': localParameter.updatechk,
    'name': '🔄 업데이트 알림 [켜기/끄기]',
    'desc': '새 버전이 나올 시 업데이트 확인 알림을 띄울지 여부를 설정할 수 있습니다.',
    'id': -1,
    'func': menuFunctionUpdateCheck,
    'visible': true,
  },
  'resetdefaults': {
    'param_name': null,
    'name': '🛠 스크립트 기본값 초기화',
    'desc': '스크립트의 사용자 설정을 초기화하고 설치 상태로 되돌립니다.',
    'id': -1,
    'func': menuFunctionRstDefaults,
    'visible': true,
  },
  'expandmenu': {
    'param_name': localParameter.expandmenu,
    'name': '⚙️ 스크립트 메뉴 [축소/확장]',
    'desc': '스크립트 설정 메뉴를 확장하거나 축소할 수 있습니다.',
    'id': -1,
    'func': menuFunctionChangeExpandMode,
    'visible': true,
  },
};

function getLocation(href) {
    var match = href.toString().match(/^(https?\:)\/\/(([^:\/?#]*)(?:\:([0-9]+))?)([\/]{0,1}[^?#]*)(\?[^#]*|)(#.*|)$/);
    return match && {
        href: href,
        protocol: match[1],
        host: match[2],
        hostname: match[3],
        port: match[4],
        pathname: match[5],
        search: match[6],
        hash: match[7]
    }
}

//auto add padding - add '=' padding in base64 encoded string
function base64AddPadding(str) {
    return str + Array((4 - str.length % 4) % 4 + 1).join('=');
}

//base64 decode
const Base64 = {
  _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
  decode : function (input) {
    let output = "";
    let chr1, chr2, chr3;
    let enc1, enc2, enc3, enc4;
    let i = 0;

    input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

    while (i < input.length) {
      enc1 = this._keyStr.indexOf(input.charAt(i++));
      enc2 = this._keyStr.indexOf(input.charAt(i++));
      enc3 = this._keyStr.indexOf(input.charAt(i++));
      enc4 = this._keyStr.indexOf(input.charAt(i++));

      chr1 = (enc1 << 2) | (enc2 >> 4);
      chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
      chr3 = ((enc3 & 3) << 6) | enc4;

      //last bits
      output = output + String.fromCharCode(chr1);
      if (enc3 != 64) { //=
        output = output + String.fromCharCode(chr2);
      }
      if (enc4 != 64) { //==
        output = output + String.fromCharCode(chr3);
      }
    }

    output = Base64._utf8_decode(output);
    return output;
  },
  // private method for UTF-8 decoding
  _utf8_decode : function (utftext) {
    let string = "";
    let i = 0;
    let c = 0;
    let c1 = 0;
    let c2 = 0;
    let c3 = 0;

    while (i < utftext.length) {
      c = utftext.charCodeAt(i);
      if (c < 128) {
        string += String.fromCharCode(c);
        i++;
      }
      else if ((c > 191) && (c < 224)) {
        c2 = utftext.charCodeAt(i+1);
        string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
        i += 2;
      }
      else {
        c2 = utftext.charCodeAt(i+1);
        c3 = utftext.charCodeAt(i+2);
        string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
        i += 3;
      }
    }
    return string;
  }
};

//encoded link click callback
function showEncodedLink(event) {
  const self = event.currentTarget;
  //check already clicked
  if (encodedList.hasOwnProperty(self.id)) {
    window.console.log(logPromptDEF, 'show encoded link -', encodedList[self.id]);
    self.innerHTML = encodedList[self.id];
    self.style.color = 'rgb(71 88 188)';
    self.title = '디코딩 전 인코딩된 링크입니다, 클릭 시 내용이 복사됩니다.';
    delete encodedList[self.id];
  } else {
    window.console.log(logPromptDEF, 'copy link to clipboard -', self.innerHTML);
    try {
      GM.setClipboard(self.innerHTML);
      window.alert(logPromptDEF+'\n인코딩된 코드가 클립보드로 복사되었습니다.');
    } catch (e) {
      window.console.warn(logPromptDEF, 'error occured link copy:', e);
      window.alert(logPromptDEF+'\n코드 복사 실패.');
    }
  }
  return;
}

//link area
function createEncodedLink(src) {
  return '<span style="font-size: 87.5%;color: rgb(71 188 115);">[ ' + src.toString() + ' ]</span>';
}

//encoded link element
function createMaskEncodedLink(src) {
  const uuid = 'abad_'+self.crypto.randomUUID();
  encodedList[uuid] = src;
  return '<span id="' + uuid.toString() + '" title="클릭 시 디코딩 전 인코딩된 링크를 표시합니다.">' + '클릭 시 인코딩된 코드 보기' + '</span>';
}

//link creation
function createLink(src, index, url, depth, hidelink = false) {
  //n번째 링크 (base64 깊이: 0) [ ABCDEF= / 클릭시 원본~ ]
  return '<a href="'+url+'" title="'+url+' (새 창으로 열기)" target="_blank" rel="external nofollow noopener noreferrer">'+index.toString()+'번째 링크 (base64 깊이: '+depth.toString()+') <span style="font-size: 77.5%;">('+getLocation(url).hostname+')</span></a> '+(hidelink?createEncodedLink(createMaskEncodedLink(src)):createEncodedLink(src))+'';
}

//decode & generate
function replacerGen(numIter) {
  return function(source) {
    try {
      let rstring = ""; //return msg
      window.console.log('\n'+logPromptDEF,'No.',(hindex+1),'encoded link:\n', source.toString()); //source

      //decode
      let converted = Base64.decode(base64AddPadding(source));
      //attempt to decode nested base64 encoded string
      for (let i=0; i<numIter; i++) {
          converted = Base64.decode(base64AddPadding(converted));
      }
      hindex++;

      //remove invalid string - �
      converted = decodeURI(encodeURI(converted).replaceAll('%00', ''));
      window.console.log(logPromptDEF,'No.',hindex,'decode completed (depth:',numIter+1,'):\n',converted.toString()); //converted

      //trim
      converted = converted.trim();

      //split by new line
      converted = converted.split(/\r?\n/);
      //single component
      if (converted.length == 2 && converted[converted.length-1] == '') {
        rstring += createLink(source, hindex, converted[0], numIter+1, !localParameter.enclinkhide.value);
      //multiple component
      } else if (converted.length > 1) {
        rstring += createEncodedLink(localParameter.enclinkhide.value?source.toString():createMaskEncodedLink(source.toString()));

        let nindex = 1;
        const hindexPrev = hindex;
        converted.forEach(function(i) {
          if (i != '') {
            rstring += '<br><span style="margin-left:2px;">└ </span>' + createLink('<span style="color: rgb(71 188 115);" title="자동으로 분할된 '+nindex.toString()+'번째 링크입니다.">링크 자동 분할 : '+nindex.toString()+'번째</span>', hindex, i, numIter+1);
            hindex++;
            nindex++;
          }
        });
        //apply last components
        hindex--;
        nindex--;

        window.console.log(logPromptDEF,'No.',hindexPrev,'- splitted total :', nindex);
        rstring = '<span style="color: rgb(232 62 140);"><b><i>분할된 링크 총 '+nindex.toString()+'개</i></b></span> ' + rstring;
      } else rstring += createLink(source, hindex, converted, numIter+1, !localParameter.enclinkhide.value);
      return rstring;
    } catch(e) {
      window.console.warn('\n'+logPromptDEF,'error occured during decoding:', e);
      window.console.warn(logPromptDEF,'base64 decode fail:', source);
    }
    return '<span style="color: rgb(255 0 0);">[ base64 변환 실패: '+source.toString()+' ]</span>';
  };
}

//user drag event
function selClicked(event) {
  const sel = document.getSelection().toString();
  if (!sel.match(regInvalid) && sel.length >= 10 && lastSelectedTime + 200 < Date.now()) {
    try {
      window.console.log(logPromptDEF,'live match -',sel.toString());
      let converted = decodeURI(encodeURI(Base64.decode(base64AddPadding(sel))).replaceAll('%00', ''));
      window.console.log(logPromptDEF,'converted -',converted.toString());
      this.innerHTML = this.innerHTML.replace(sel, converted)+' ';
    } catch (e) {
      return;
    } finally {
      this.removeEventListener('click', selClicked);
    }
  }
}

//user drag activate
function activateDragDecoding() {
  if (draggableActivated) {
    window.console.log(logPromptDEF,'USR-Drag already enabled.');
    return;
  }
  draggableActivated = true;
  window.console.log(logPromptDEF,'USR-Drag enabled.');
  document.addEventListener('selectionchange', function() {
    let sel = document.getSelection().anchorNode;
    if (sel) {
      sel = sel.parentElement;
      if (sel != lastSelected) {
        lastSelected.removeEventListener('click', selClicked);
        sel.addEventListener('click', selClicked);
        lastSelected = sel;
        lastSelectedTime = Date.now();
      }
    }
  });
}

//update check
function checkForUpdate() {
  if (!updateAvailble || !localParameter.updatechk.value) {
    window.console.log(logPromptUPD,'updchk skipped.');
    return;
  }
  const currentTime = Math.floor(new Date().getTime() / 1000);
  if (currentTime - localParameter.lastupdate.value < updateInterval) {
    window.console.log(logPromptUPD,'updchk already done in 1 day.. skip updchk');
    return;
  }
  try {
    GM.setValue(localParameter.lastupdate.param_name, currentTime);
  } catch(e) {
    window.console.error(logPromptUPD,'last upd time write fail -', e);
    return;
  }

  window.console.log(logPromptUPD,'checking for update...');
  const updateLink = 'https://update.greasyfork.org/scripts/482577/Arca%20base64%20autodecoder.meta.js';
  fetch(updateLink)
  .then(response => response.text())
  .then(data => {
    //extract version from greaskyfork script
    const match = data.match(/@version\s+(\d+\.\d+)/);
    if (match) {
      const tar_version = parseFloat(match[1]);
      const cur_version = parseFloat(GM.info.script.version);
      //new version detected
      if (tar_version > cur_version) {
        window.console.log(logPromptUPD,'new version available. ('+cur_version+' -> '+tar_version+')');
        //y/n dialog
        if (window.confirm(logPromptDEF+'\n새로운 버전이 감지되었습니다. 업데이트를 권장합니다.\n( 기존버전 : '+cur_version+', 새로운 버전 : '+tar_version+' )\n(변경사항은 아카라이브 게시글을 참고해주세요.)\n\n취소를 누르면 앞으로 업데이트 알림을 띄우지 않습니다.')) {
          //get extension env
          if (!GM.info.scriptWillUpdate) {
            window.console.log(logPromptUPD,'extension not allowed auto update..');
            if (window.confirm(logPromptDEF+'\n주의! 스크립트 내용 변경 등으로 인해 확장프로그램 내 자동 업데이트가 꺼져있는 것 같습니다.\n업데이트 시 기존 스크립트에 덮어쓰게 되어 기존 내용이 손실될 수 있습니다.\n이 점 확인 후 업데이트 바랍니다.\n\n(계속하려면 확인, 취소하려면 취소를 눌러주세요.)')) {
              window.console.log(logPromptUPD,'opening source url..');
              window.location.replace(updateLink);
              window.alert(logPromptDEF+'\n업데이트 후 새로고침해야 적용됩니다.');
            } else {
              window.console.log(logPromptUPD,"user canceled.");
            }
          } else {
            window.console.log(logPromptUPD,'opening source url..');
            window.location.replace(updateLink);
            window.alert(logPromptDEF+'\n업데이트 후 새로고침해야 적용됩니다.');
          }
        } else {
          window.console.log(logPromptPARAM,'updatechk change',true.toString(),'to',false.toString());
          try {
            GM.setValue(localParameter.updatechk.param_name, false);
            localParameter.updatechk.value = false;
            window.console.log(logPromptPARAM,"updatechk change successful");
            menuStructureUpdate();
            window.alert(logPromptDEF+'\n앞으로 업데이트 알림을 띄우지 않습니다.');
          } catch(e) {
            localParameter.updatechk.value = true;
            window.console.error(logPromptPARAM,"updatechk change fail -", e);
            window.alert(logPromptDEF+'\n파라미터 변경 중 문제 발생, 브라우저 로그를 확인해주세요..');
          }
        }
      } else {
        window.console.log(logPromptUPD,'latest version', cur_version, 'detected. (eth:',tar_version,')');
      }
    } else {
      window.console.error(logPromptUPD,'unable to extract version..');
    }
  })
  .catch(error => {
    updateAvailble = false;
    window.console.error(logPromptUPD,'link unreachable.. -', error);
  });
  updateAvailble = false;
}

//menu update
function menuStructureUpdate(fistRun = false) {
  //pre process
  localParameter.basedepth.value = localParameter.basedepth.value > autoDecodingMaximum ? autoDecodingMaximum : localParameter.basedepth.value;

  //update menu name
  menuStructure.basedepth.name = '🎛 base64 깊이 조절하기 - 현재 값 : '+localParameter.basedepth.value+'회';
  menuStructure.enclinkhide.name = '🔗 인코딩된 링크 '+(localParameter.enclinkhide.value?'숨기기':'보이기');
  menuStructure.draggable.name = '🖱 드래그 시 자동 디코딩 '+(localParameter.draggable.value?'끄기':'켜기');
  menuStructure.updatechk.name = '🔄 업데이트 알림 '+(localParameter.updatechk.value?'끄기':'켜기');
  menuStructure.expandmenu.name = '⚙️ 스크립트 메뉴 '+(localParameter.expandmenu.value?'축소':'확장');

  //remove exist menu cmd
  if (!fistRun) {
    Object.keys(menuStructure).forEach(function(i) {
      try {
        GM.unregisterMenuCommand(menuStructure[i].id);
      } catch(_) {}
    });
  }
  //monkey menu cmd register
  try {
    //all menu expanded
    if(localParameter.expandmenu.value) {
      Object.keys(menuStructure).forEach(function(i) {
        if (menuStructure[i].visible) {
          menuStructure[i].id = GM.registerMenuCommand(menuStructure[i].name, menuStructure[i].func, {title:menuStructure[i].desc});
        } else {
          //if invisible -> use default parameter
          if (localParameter.hasOwnProperty(i)) {
            localParameter[i].value = localParameter[i].def_value;
          }
        }
      });
    //simple menu
    } else {
      menuStructure.expandmenu.id = GM.registerMenuCommand(menuStructure.expandmenu.name, menuStructure.expandmenu.func, {title:menuStructure.expandmenu.desc});
    }
    window.console.log(logPromptPARAM,'ext opt pannel',(fistRun?'registered':'reloaded'));
  } catch(e) {
    window.console.error(logPromptPARAM,'err - ext opt pannel',(fistRun?'register':'reload'),'- ', e);
    Object.keys(menuStructure).forEach(function(i) {
      try {
        GM.unregisterMenuCommand(menuStructure[i].id);
      } catch(_) {}
    });
    try { GM.registerMenuCommand('ⓘ 메뉴 추가 실패, 브라우저 로그 참고', () => {window.alert(logPromptDEF+'\n메뉴 추가 도중 문제가 발생했습니다, 브라우저 로그를 확인해주세요..')}); } catch(_) {}
  }
}

function menuFuncSubPageReload(showmsg) {
  if(window.confirm(logPromptDEF+'\n'+((showmsg==undefined)?'':(showmsg+'\n\n'))+'반영을 위해 사이트 새로고침이 필요합니다, 사이트를 새로고침할까요?')) {
    window.location.reload(true);
  }
}

function menuFunctionBasedepth() {
  menuStructureUpdate();
  const previousValue = localParameter.basedepth.value;
  const str_common_1 = ' ( 지정 가능한 범위: 1~'+autoDecodingMaximum.toString()+' )';
  while(true) {
    const input = window.prompt(logPromptDEF+'\nBase64 자동 디코딩 중첩 횟수를 얼마로 지정할까요?\n(인코딩을 인코딩한 것을 여러번 반복한걸 자동으로 풀어냅니다.)\n현재 값: '+previousValue.toString()+'회,'+(previousValue == 3 ? '' : ' 기본값: 3회,')+str_common_1+'\n\n(값을 너무 크게 지정하면 컴퓨터 성능에 영향을 줄 수 있습니다.)', previousValue);
    if (input == null) {
      window.console.log(logPromptDEF,'basedepth change canceled.');
      break;
    }
    if (!isNaN(input)) {
      const targetValue = parseInt(input);
      if (targetValue == previousValue) {
        window.alert(logPromptDEF+'\n동일한 값을 입력했습니다, 현재 값: '+previousValue+'회');
      } else if (targetValue >= 1 && targetValue <= autoDecodingMaximum) {
        window.console.log(logPromptPARAM,'basedepth change',previousValue.toString(),'to',targetValue.toString());
        localParameter.basedepth.value = targetValue;
        try {
          GM.setValue(localParameter.basedepth.param_name, targetValue);
          window.console.log(logPromptPARAM,"basedepth change successful");
          menuFuncSubPageReload('값이 '+previousValue.toString()+'에서 '+targetValue.toString()+'으로 변경이 완료되었습니다.');
        } catch(e) {
          localParameter.basedepth.value = previousValue;
          window.console.error(logPromptPARAM,"basedepth change fail -", e);
          window.alert(logPromptDEF+'\n파라미터 변경 중 문제 발생, 브라우저 로그를 확인해주세요..');
        } finally {
          menuStructureUpdate();
        }
        break;
      } else {
        window.alert(logPromptDEF+'\n'+targetValue+'(으)로 설정할 수 없습니다.\n범위를 초과하였습니다..'+str_common_1);
      }
    } else {
      window.alert(logPromptDEF+'\n'+input+'은(는)숫자가 아닙니다.\n숫자만 입력해주세요..'+str_common_1);
    }
  }
}

function menuFunctionEnchide() {
  menuStructureUpdate();
  const currentState = localParameter.enclinkhide.value;
  if (window.confirm(logPromptDEF+'\n디코딩 시 인코딩된 링크를 '+(currentState?'숨기시':'표시하')+'겠습니까?\n\n(앞으로 디코딩 전 인코딩된 링크를\n"'+(currentState?'클릭 시 기존링크 보기':'aHR0cHM6Ly9hcmNhLmx..')+'"와 같은 형태로 보여줍니다.)')) {
    const targetState = !currentState;
    window.console.log(logPromptPARAM,'enchide change',currentState.toString(),'to',targetState.toString());
    localParameter.enclinkhide.value = targetState;
    try {
      GM.setValue(localParameter.enclinkhide.param_name, targetState);
      window.console.log(logPromptPARAM,"updatechk change successful");
      if (targetState) {
        window.alert(logPromptDEF+'\n앞으로 인코딩된 링크를 표시합니다.\n\n(새로고침해야 적용됩니다.)');
      } else {
        window.alert(logPromptDEF+'\n앞으로 인코딩된 링크를 숨깁니다.');
      }
    } catch(e) {
      localParameter.enclinkhide.value = currentState;
      window.console.error(logPromptPARAM,"enchide change fail -", e);
      window.alert(logPromptDEF+'\n파라미터 변경 중 문제 발생, 브라우저 로그를 확인해주세요..');
    } finally {
      menuStructureUpdate();
    }
  } else {
    window.console.log(logPromptDEF,'enchide change canceled.');
  }
}

function menuFunctionDraggable() {
  menuStructureUpdate();
  const currentState = localParameter.draggable.value;
  if (window.confirm(logPromptDEF+'\n드래그 시 자동 디코딩을 '+(currentState?'비':'')+'활성화 하시겠습니까?\n\n(앞으로 인코딩된 부분을 드래그'+(currentState?'해도 자동으로 디코딩되지 않습':' 시 Base64로 인코딩된것으로\n판단 되면 자동으로 디코딩을 시도합')+'니다.)\n\n(이 기능은 작동이 불안정할 수 있습니다.)')) {
    const targetState = !currentState;
    window.console.log(logPromptPARAM,'draggable change',currentState.toString(),'to',targetState.toString());
    localParameter.draggable.value = targetState;
    try {
      GM.setValue(localParameter.draggable.param_name, targetState);
      window.console.log(logPromptPARAM,"draggable change successful");
      if (targetState) {
        try {
          activateDragDecoding();
          window.alert(logPromptDEF+'\n앞으로 드래그 시 자동 디코딩을 진행합니다.');
        } catch(e) {
          window.console.error(logPromptDEF,"draggable activate fail -", e);
          window.alert(logPromptDEF+'\n드래그 시 자동 디코딩 활성화 중 문제가 발생했습니다, 브라우저 로그를 확인해주세요..\n새로고침이 필요합니다..');
        }
      } else {
        menuFuncSubPageReload('앞으로 드래그 해도 반응하지 않습니다.');
      }
    } catch(e) {
      localParameter.draggable.value = currentState;
      window.console.error(logPromptPARAM,"draggable change fail -", e);
      window.alert(logPromptDEF+'\n파라미터 변경 중 문제 발생, 브라우저 로그를 확인해주세요..');
    } finally {
      menuStructureUpdate();
    }
  } else {
    window.console.log(logPromptDEF,'draggable change canceled.');
  }
}

function menuFunctionUpdateCheck() {
  menuStructureUpdate();
  const currentState = localParameter.updatechk.value;
  if (window.confirm(logPromptDEF+'\n업데이트 알림을 '+(currentState?'끄':'켜')+'시겠습니까?\n\n(앞으로 업데이트가 있'+(currentState?'어도 알려주지 않습':'으면 자동으로 알려줍')+'니다.)')) {
    const targetState = !currentState;
    window.console.log(logPromptPARAM,'updatechk change',currentState.toString(),'to',targetState.toString());
    localParameter.updatechk.value = targetState;
    try {
      GM.setValue(localParameter.updatechk.param_name, targetState);
      window.console.log(logPromptPARAM,"updatechk change successful");
      if (targetState) {
        window.alert(logPromptDEF+'\n앞으로 업데이트가 존재하면 알림을 띄웁니다.');
      } else {
        window.alert(logPromptDEF+'\n앞으로 업데이트 알림을 띄우지 않습니다.');
      }
    } catch(e) {
      localParameter.updatechk.value = currentState;
      window.console.error(logPromptPARAM,"updatechk change fail -", e);
      window.alert(logPromptDEF+'\n파라미터 변경 중 문제 발생, 브라우저 로그를 확인해주세요..');
    } finally {
      menuStructureUpdate();
    }
  } else {
    window.console.log(logPromptDEF,'updatechk change canceled.');
  }
}

function menuFunctionChangeExpandMode() {
  menuStructureUpdate();
  const currentState = localParameter.expandmenu.value;
  if (window.confirm(logPromptDEF+'\n메뉴에 나타나는 항목을 '+(currentState?'줄일':'늘릴')+'까요?\n\n(앞으로 세부설정 메뉴가 '+(currentState?'숨겨':'보여')+'집니다.)')) {
    const targetState = !currentState;
    window.console.log(logPromptPARAM,'menuexpand change',currentState.toString(),'to',targetState.toString());
    localParameter.expandmenu.value = targetState;
    try {
      GM.setValue(localParameter.expandmenu.param_name, targetState);
      window.console.log(logPromptPARAM,"menuexpand change successful");
      if (targetState) {
        window.alert(logPromptDEF+'\n세부설정 메뉴가 보여집니다.');
      } else {
        window.alert(logPromptDEF+'\n세부설정 메뉴가 숨겨집니다.');
      }
    } catch(e) {
      localParameter.expandmenu.value = currentState;
      window.console.error(logPromptPARAM,"menuexpand change fail -", e);
      window.alert(logPromptDEF+'\n파라미터 변경 중 문제 발생, 브라우저 로그를 확인해주세요..');
    } finally {
      menuStructureUpdate();
    }
  } else {
    window.console.log(logPromptDEF,'menuexpand change canceled.');
  }
}

function menuFunctionRstDefaults() {
  menuStructureUpdate();
  if (window.confirm(logPromptDEF+'\n정말 스크립트 설정을 기본값으로 초기화하시겠습니까?\n\n(초기화 완료 후 자동으로 새로고침됩니다.)')) {
    try {
      window.console.log(logPromptPARAM, 'remove all settings..');
      for (const i of Object.keys(localParameter)) {
        GM.deleteValue(localParameter[i].param_name);
      }
      window.console.log(logPromptPARAM, 'all parameter removed.');
      window.alert(logPromptDEF+'\n설정값이 모두 제거되었습니다.\n\n(확인 후 현재 창이 자동으로 새로고침됩니다.)');
      window.location.reload(true);
    } catch(e) {
      window.console.error(logPromptPARAM,'err - get sc parameter - ', e);
      window.alert(logPromptDEF+'\n경고! 파라미터 초기화 도중 문제가 발생했습니다. 브라우저 로그를 참고해주세요..');
    }
  } else {
    window.console.log(logPromptDEF,'settings restore canceled.');
  }
}

//main
(async () => {
  'use strict';

  //chk browser env
  if (((window.navigator.language || window.navigator.userLanguage) != 'ko-KR')) {
    window.console.warn('Warning! this script support only korean language..');
  }

  //check edit mode
  const URLSuffix = window.location.pathname.match(/([/][a-z0-9_-]*[\/]?)$/g);
  if (URLSuffix != null) {
    if (deniedURLSuffix.some(str => str == URLSuffix[0])) {
      window.console.log(logPromptDEF,'write/edit mode detected, function disabled.');
      try {GM.registerMenuCommand("작성/수정 모드에서는 동작하지 않음", ()=>{window.alert(logPromptDEF+'\n작성 또는 수정모드에서는 동작하지 않습니다..');}, {title:'작성 또는 수정모드에서는 동작하지 않습니다.'});} catch(_) {}
      return;
    }
  }

  window.console.log(logPromptDEF,'V',GM.info.script.version,'enabled');

  //load parameter
  try {
    for (const i of Object.keys(localParameter)) {
      localParameter[i].value = await GM.getValue(localParameter[i].param_name, localParameter[i].def_value);
    }
    window.console.log(logPromptPARAM, 'sc parameter load completed.');
  } catch(e) {
    window.console.error(logPromptPARAM,'err - get sc parameter - ', e);
  }

  //apply parameter and register monkey menu command
  menuStructureUpdate(true);

  //chk update
  await checkForUpdate();

  //drag auto decoding
  if (localParameter.draggable.value) {
    activateDragDecoding();
  }

  window.console.log(logPromptDEF,'script ready');
  //main procedure

  //article
  let article = document.getElementsByClassName("article-content")[0];
  if (article != undefined) {
    for (let i=0; i<localParameter.basedepth.value; i++) {
      article.innerHTML = article.innerHTML.replaceAll(regexEncodedPrefixDef[i], replacerGen(i));
    }
  } else window.console.warn(logPromptDEF,'no article detected.');

  //comment
  let comments = document.getElementsByClassName("list-area");
  if (article != undefined) {
    if (comments.length != 0) {
      for (let i=0; i<localParameter.basedepth.value; i++) {
        comments[0].innerHTML = comments[0].innerHTML.replaceAll(regexEncodedPrefixDef[i], replacerGen(i));
      }
    }
  } else window.console.warn(logPromptDEF,'no comments detected.');
  window.console.log(logPromptDEF,'total',hindex,'link decode task completed.');

  //add eventlistner - click, show original encoded link
  if (!localParameter.enclinkhide.value) {
    Object.keys(encodedList).forEach(function(i) {
      document.getElementById(i).addEventListener('click', showEncodedLink); //, { once : true }
    });
  }
})();