// ==UserScript==
// @name         AO3: Fic's Style, Blacklist, Bookmarks
// @namespace    https://github.com/Schegge
// @version      3.1
// @description  Change font, size, width, background... of a work + number of words for each chapter and estimated reading time + blacklist/savior: hide works that contain certains tags + fullscreen reading mode + bookmarks: save the position you stopped reading a fic
// @author       Schegge
// @include      http*://archiveofourown.org/*
// @grant        none
// @icon         data:image/png;base64,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
// @downloadURL none
// ==/UserScript==

(function() {
   // CSS changes
   function addCSS(id, css) {
      if (!document.querySelector('style#' + id)) {
         let style = document.createElement('style');
         style.id = id;
         style.textContent = css;
         document.getElementsByTagName('head')[0].appendChild(style);
      } else {
         document.querySelector('style#' + id).textContent = css;
      }
   }

   // estimate reading time
   function countTime(num) {
      // 200 words per minute
      let timeReading = parseInt(num, 10) / 200;
      if (timeReading < 60) {
         timeReading = Math.round(timeReading) + 'min';
      } else {
         timeReading = (timeReading / 60).toFixed(2);
         timeReading = timeReading.toString().split('.');
         timeReading = timeReading[0] + 'hr ' + Math.round(parseInt(timeReading[1], 10) / 100 * 60) + 'min';
      }
      return timeReading;
   }

   function getScroll() {
      return Math.max(document.documentElement.scrollTop, window.scrollY);
   }
   function setScroll(s) {
      window.scroll(0, s ? s : 0);
   }
   function getDocHeight() {
      return Math.max(document.documentElement.scrollHeight, document.documentElement.offsetHeight, document.body.scrollHeight, document.body.offsetHeight);
   }

   // BOOKMARKS
   var BM = [];
   var Bookmarks = {
      getBooks: function() {
         if (localStorage.getItem('ficstyle_bookmarks')) BM = JSON.parse(localStorage.getItem('ficstyle_bookmarks'));
      },
      saveBooks: function() {
         localStorage.setItem('ficstyle_bookmarks', JSON.stringify(BM));
      },
      getUrl: window.location.pathname.split('/works/')[1],
      getTitle: function() {
         let title = document.querySelector('#workskin .preface.group h2.title.heading').textContent;
         // cut long titles
         title = title.trim().substring(0, 28);
         // if chapter by chapter, get the number of the chapter
         if (this.getUrl.indexOf('chapters') !== -1) {
            let chapter = document.querySelector('#chapters > .chapter > .chapter.preface.group > h3 > a').textContent;
            chapter = chapter.replace('Chapter ', 'ch');
            title += ' (' + chapter + ')';
         }
         return title;
      },
      getNewBook: function() {
         let newbook = getScroll();
			// # chapters
         let chs = document.querySelector('dl.stats dd.chapters').textContent;
			// if work completed (if number/number is the same) or chapter by chapter view
         if (/(\d+)\/\1/.test(chs) || window.location.pathname.indexOf('chapters') !== -1) {
				// calculate as a percent
            newbook = (newbook / getDocHeight()).toFixed(4) + '%';
         }
         return newbook;
      },
      checkIfExist: function(a, b) {
         let url = b || this.getUrl;
         for (let i = 0; i < BM.length; i++) {
            // if a bookmark already existed for the current chapter
            if (BM[i][0] === url) {
					// retrieve the bookmark
               if (a === 'book') {
                  let book = BM[i][2];
                  if (book.toString().indexOf('%') !== -1) {
                     book = parseFloat(book.replace('%', ''));
                     book *= getDocHeight();
                  }
                  return book;
               // delete the old bookmark
               } else if (a === 'cancel') {
                  return i;
               // check if it exists
               } else {
                  return true;
               }
				// if a bookmark already existed for the current fic, delete the old bookmark
            } else if (a === 'cancel' && BM[i][0].split('/chapters/')[0] === url.split('/chapters/')[0]) {
               return i;
            }
         }
         return false;
      },
      cancel: function(url) {
         let found = this.checkIfExist('cancel', url);
         if (found !== false) BM.splice(found, 1);
      },
      getNew: function() {
			this.cancel();
         BM.push([this.getUrl, this.getTitle(), this.getNewBook()]);
         this.saveBooks();
      }
   };
   Bookmarks.getBooks();

   // Bookmarks' menu
   addCSS(
      'ficstyle-menu',
      '#menu-bookmarks ul li { display: flex!important; align-items: center; justify-content: space-between; } ' +
      '#menu-bookmarks ul li a:first-child { flex-grow: 1; font-size: .9em; } ' +
      'a.delete-book-menu { color: #900!important; } '
   );

   var bmMenu = document.createElement('li');
   var bmMenuDrop = document.createElement('ul');
   bmMenu.id = 'menu-bookmarks';
   bmMenu.className = 'dropdown';
   bmMenu.innerHTML = '<a>Bookmarks</a>';
   bmMenuDrop.className = 'menu dropdown-menu';
   bmMenu.appendChild(bmMenuDrop);
   document.querySelector('#header > ul').appendChild(bmMenu);

   if (BM.length) {
      let clickDelete = function() {
         Bookmarks.cancel(this.getAttribute('data-url'));
         Bookmarks.saveBooks();
         this.style.display = 'none';
         this.previousSibling.style.opacity = '.4';
      };

      for (let z = 0; z < BM.length; z++) {
         let bmLi = document.createElement('li');
         bmLi.innerHTML = '<a href="https://archiveofourown.org/works/' + BM[z][0] + '">' + BM[z][1] + '</a>';
         let deleteBookMenu = document.createElement('a');
         deleteBookMenu.className = 'delete-book-menu';
         deleteBookMenu.title = 'delete bookmark';
         deleteBookMenu.setAttribute('data-url', BM[z][0]);
         deleteBookMenu.textContent = 'x';
         bmLi.appendChild(deleteBookMenu);
         bmMenuDrop.appendChild(bmLi);
         deleteBookMenu.addEventListener('click', clickDelete);
      }
   } else {
      bmMenuDrop.innerHTML = '<li><a>No bookmark yet.</a></li>';
   }

   // add estimated reading time for every fic found
   var statsWords = document.querySelectorAll('dl.stats dd.words');
   for (let s = 0; s < statsWords.length; s++) {
      let numWords = statsWords[s].textContent.replace(/,/g, '');
      statsWords[s].insertAdjacentHTML('afterend', '<dt>Time:</dt><dd>' + countTime(numWords) + '</dd>');
   }

   // BLACKLIST: ONLY ON SEARCH PAGES but not on personal user profile
   let user = document.querySelector('#greeting .user a[href*="/users/"]');
   user = user ? window.location.pathname.indexOf(user.href.split('/users/')[1]) === -1 : true;
   var Blacklist = {where: 'li.blurb.group'};
   if (document.querySelector(Blacklist.where) && user) {
      var BL = [];
      Blacklist.what = [
         '.tags .tag',
         '.required-tags span.text'
      ];
      Blacklist.show = localStorage.getItem('ficstyle_blacklist_show') || true;
      Blacklist.get = function() {
         if (localStorage.getItem('ficstyle_blacklist')) BL = JSON.parse(localStorage.getItem('ficstyle_blacklist'));
      };
      Blacklist.set = function(v) {
         let items = v ? v.trim().replace(/[\\"]/g, '\\$&').split(',').join('","') : '';
         items = items ? '["' + items + '"]' : '[]';
         localStorage.setItem('ficstyle_blacklist', items);
         this.get();
      };
      Blacklist.get();

      addCSS(
         'ficstyle-blacklist',
         '#menu-blacklist ul li { text-align: center!important; }' +
         '#fs-save-ta {color: #900!important; font-weight: bold; } ' +
         '#menu-blacklist textarea { font-size: .9em; line-height: 1.2em; min-height: 10em; margin: .5em!important; padding: .3em; box-shadow: 0 0 0 1px #888; width: calc(100% - 1em); border: 0; box-sizing: border-box; resize: vertical; } ' +
         '#menu-blacklist .fs-black-info { font-size: .9em; font-variant: small-caps; }' +
         '#menu-blacklist .fs-black-info span { padding: 0 2em; }' +
         Blacklist.where + '[data-visibility="remove"] { display: none; } ' +
         Blacklist.where + '[data-visibility="hide"] { opacity: .6; } ' +
         Blacklist.where + '[data-visibility="hide"] > *:not(.header), ' +
         Blacklist.where + '[data-visibility="hide"] .required-tags, ' +
         Blacklist.where + '[data-visibility="hide"] .fandoms.heading:not(.reasons) { display: none; }' +
         Blacklist.where + '[data-visibility="hide"] > .header { margin: 0!important; }' +
         Blacklist.where + '[data-visibility="hide"] .reasons > span { color: #fff; background-color: #900; padding: 0 .2em; } '
      );

      // Blacklist's menu
      var blMenu = document.createElement('li');
      blMenu.id = 'menu-blacklist';
      blMenu.className = 'dropdown';
      blMenu.innerHTML = '<a>Blacklist</a><ul class="menu dropdown-menu" role="menu">' +
         '<li role="menu-item"><a id="fs-save-ta">SAVE</a></li>' +
         '<li role="menu-item"><textarea id="fs-blacklist"></textarea></li>' +
         '<li role="menu-item"><div class="fs-black-info"><span>separator: ,</span><span>wildcard: *</span></li>' +
         '<li role="menu-item"><a id="fs-blacklist-show">Hide blacklisted works</a></ul>';
      document.querySelector('#header > ul').appendChild(blMenu);
      if (!Blacklist.show) document.getElementById('fs-blacklist-show').textContent = 'Show reasons for blacklisting';

      // blacklisting
      var Blacklisting = {
         ifMatch: function(t) {
            for (let j = 0; j < BL.length; j++) {
               var b = BL[j].trim().toLowerCase();
               if (b.length) {
                  let r = b.replace(/[.+?^${}()|[\]\\]/g, '\\$&').replace(/\*/g, '.*');
                  let reg = new RegExp('^' + r + '$');
                  if (reg.test(t)) return true;
               }
            }
            return false;
         },
         findMatch: function(w) {
            var whereWhat = document.querySelectorAll(Blacklist.where + ' ' + w);
            for (let i = 0, len = whereWhat.length; i < len; i++) {
               let tag = whereWhat[i].textContent.trim().toLowerCase();
               if (tag && this.ifMatch(tag)) {
                  if (Blacklist.show) {
                     whereWhat[i].closest(Blacklist.where).setAttribute('data-visibility', 'hide');
                     let reasons = whereWhat[i].closest(Blacklist.where).getAttribute('data-reasons');
                     whereWhat[i].closest(Blacklist.where).setAttribute(
                        'data-reasons',
                        !reasons ? tag : reasons.trim() + ', ' + tag
                     );
                  } else {
                     whereWhat[i].closest(Blacklist.where).setAttribute('data-visibility', 'remove');
                  }
               }
            }
         },
         addReasons: function() {
            var whereReasons = document.querySelectorAll(Blacklist.where + '[data-reasons]');
            for (let i = 0, len = whereReasons.length; i < len; i++) {
               whereReasons[i].querySelector('h4.heading').insertAdjacentHTML('afterend', '<h5 class="fandoms heading reasons"><span>blacklisted</span> ' + whereReasons[i].getAttribute('data-reasons') + '</h5>');
            }
         },
         clear: function() {
            document.querySelectorAll(Blacklist.where + '[data-visibility]').forEach(function(el) {
               el.removeAttribute('data-visibility');
               el.removeAttribute('data-reasons');
               if (Blacklist.show) el.querySelector('.reasons').remove();
            });
         },
         search: function() {
            this.clear();
            if (!BL.length) return;
            for (let i = 0; i < Blacklist.what.length; i++) {
               this.findMatch(Blacklist.what[i]);
            }
            if (Blacklist.show) this.addReasons();
         },
         updateTextareas: function() {
            document.getElementById('fs-blacklist').value = BL.toString();
            this.search();
         },
         saveTextareas: function() {
            Blacklist.set(document.getElementById('fs-blacklist').value);
            this.search();
         }
      };
      Blacklisting.updateTextareas();

      document.getElementById('fs-save-ta').addEventListener('click', function() {
         Blacklisting.saveTextareas();
         this.textContent = 'SAVED';
         setTimeout(function() {
            document.getElementById('fs-save-ta').textContent = 'SAVE';
         }, 1000);
      });

      document.getElementById('fs-blacklist-show').addEventListener('click', function() {
         if (Blacklist.show) {
            Blacklist.show = false;
            this.textContent = 'Show reasons for blacklisting';
         } else {
            Blacklist.show = true;
            this.textContent = 'Hide blacklisted works';
         }
         localStorage.setItem('ficstyle_blacklist_show', Blacklist.show);
         Blacklisting.search();
      });

	}
	// end search page

   // FIC'S STYLE + FULLSCREEN + BOOKMARKING: ONLY ON WORK PAGES
   // include: /works/(numbers) and /works/(numbers)/chapters/(numbers) and exclude /works/(whatever)navigate
   if (/\/works\/\d+(\/chapters\/\d+)?(?!.*navigate)/.test(window.location.pathname)) {
      var workskin = document.getElementById('workskin');

      // default values
      var Options = {
         fontName: [
				// inherit = default
            'inherit',
            'Verdana',
            'Segoe UI',
            'Georgia',
            'Garamond',
            'Book Antiqua',
            'monospace'
			],
			// (%) (min = 50; max = 300)
			fontSize: 100,
			// (%) (min = 0; max = 40) to change text's width
			padding: 7,
         colors: {
				// background, font color
				// light = default
            light: ['#ffffff', '#000000'],
            grey: ['#eeeeee', '#111111'],
            sepia: ['#fbf0d9', '#54331b'],
            dark: ['#3c3c3c', '#e1e1e1'],
            darkblue: ['#282a36', '#f8f8e6']
         }
      };

      addCSS(
         'ficstyle-general',
         // fic's style
         '#workskin { margin: 0; text-align: justify; max-width: none!important; } ' +
         '#workskin .notes, #workskin .summary { font-size: inherit; font-family: inherit; } ' +
         '#main div.wrapper { margin-bottom: 1em; } ' +
         '.actions { font-family: \'Lucida Grande\', \'Lucida Sans Unicode\', \'GNU Unifont\', Verdana, Helvetica, sans-serif; font-size: 14px; } ' +
         '.chapter .preface { margin-bottom: 0; border-width: 0; } ' +
         '.chapter .preface[role="complementary"] { margin-top: 0; padding-top: 0; } ' +
         '.preface.group, div.preface { color: inherit; background-color: inherit; margin-left: 0; margin-right: 0; margin-top: 0; } ' +
         'div.preface .byline a { color: inherit; } ' +
         'div.preface .notes, div.preface .summary, div.preface .series, div.preface .children { min-height: 0; } ' +
         'div.preface .jump { margin-top: 1em; font-size: .9em; }' +
         '.preface blockquote { border: 3px solid rgba(0, 0, 0, .1); border-left: 0; border-right: 0; padding: .6em; margin: 0; }' +
         '.preface h3.title { background: repeating-linear-gradient(45deg, rgba(0, 0, 0, .05), rgba(0, 0, 0, .1) 2px, rgba(255, 255, 255, .2) 2px, rgba(255, 255, 255, .2) 4px); padding: .6em; margin: 0; } ' +
         '.preface h3.heading { border-width: 0; } ' +
         'h3.title a { border: 0; font-style: italic; } ' +
         'div.preface .associations, .preface .notes h3+p { margin-bottom: 0; font-style: italic; font-size: .8em; } ' +
         '.chapter .preface[role="complementary"] { border-width: 0; margin: 0; } ' +
         '#workskin #chapters, #workskin #chapters .userstuff { width: 100%!important; box-sizing: border-box; } ' +
         '#workskin #chapters .userstuff p { font-family: inherit; margin: .6em auto; text-align: justify; line-height: 1.5em; } ' +
         '#workskin #chapters .userstuff { font-family: inherit; text-align: justify; line-height: 1.5em } ' +
         '#workskin #chapters .userstuff br { display: block; margin-top: .6em; content: " "; } ' +
         '.userstuff hr { width: 100%; height: 1px; border: 0; background-image: linear-gradient(90deg, transparent, rgba(0, 0, 0, .3), transparent); margin: 1.5em 0; } ' +
         '#workskin #chapters a, #chapters a:link, #chapters a:visited { color: inherit; } ' +
         'blockquote { font-family: inherit; font-size: inherit; } ' +
         '#workskin #chapters .userstuff blockquote { padding-top: 1px; padding-bottom: 1px; margin: 0 .5em; font-size: inherit; } ' +
         '.userstuff img { max-width: 100%; height: auto; display: block; margin: auto; } ' +
         // options
         '#options.options-hide > div:nth-last-child(n+2) { display: none; }' +
         '#options, .ficleft { position: fixed; bottom: 10px; margin: 0; padding: 0; font-family: Consolas, monospace; font-size: 16px; line-height: 18px; color: #000; text-shadow: 0 0 2px rgba(0, 0, 0, .4); z-index: 999; } ' +
         '#options { right: 0; } ' +
         '#options > div { margin: 5px 0 0 0; padding: 0 5px; cursor: pointer; } ' +
         '#options > div:last-child { display: block; padding: .3em .2em; color: #fff; background-color: rgba(0, 0, 0, .2); border-radius: 4px 0 0 4px; } ' +
         '.ficleft { display: none; left: 10px; } ' +
         '.ficleft a, #options a { border: 0; color: #000; } ' +
         '.fictop { margin: 1em 0 0; font-size: 80%; text-align: right; padding: 0; } ' +
         // chapter words
         '.chapterWords { font-size: .8em; color: inherit; font-family: consolas, monospace; text-transform: uppercase; text-align: center; margin: 3em 0 .5em; }'
      );

      // CSS changes depending on the user
      var Variables = {
         init: function() {
            if (!localStorage.getItem('ficstyle')) {
               localStorage.setItem('ficstyle', JSON.stringify({
                  fontName: Options.fontName[0],
                  fontSize: Options.fontSize,
                  padding: Options.padding,
                  colors: Object.keys(Options.colors)[0]
               }));
            }
         },
         get: function() {
            return JSON.parse(localStorage.getItem('ficstyle'));
         },
         set: function(a, b) {
            let all = this.get();
            if (a && b) all[a] = b;
            localStorage.setItem('ficstyle', JSON.stringify(all));
            addCSS(
               'ficstyle-user-changes',
               '#workskin { font-family: ' + all.fontName + '; font-size: ' + all.fontSize + '%; padding: 0 ' + all.padding + '%; background-color: ' + Options.colors[all.colors][0] + '; color: ' + Options.colors[all.colors][1] + '; } '
            );
         },
         reset: function() {
            localStorage.removeItem('ficstyle');
            this.init();
            this.set();
         }
      };
		Variables.init();
      Variables.set();

      // remove all the non-breaking white spaces
      document.getElementById('chapters').innerHTML = document.getElementById('chapters').innerHTML.replace(/&nbsp;/g, ' ');

		// # words and time for every chapter, if the fic has chapters
      var numChapters = document.querySelectorAll('#chapters > .chapter').length;
      if (numChapters) {
         let chTexts = document.querySelectorAll('#chapters > .chapter > div.userstuff.module');
         chTexts.forEach(function(el) {
            let text = el.textContent.replace(/(\s-\s)|(-)/g, '').replace(/[."“”?!)(]/g, ' ');
            let words = text.match(/\S+\s/g);
				// -2 because of <h3>Chapter Text</h3>
            let numWords = words.length - 2;
            el.parentNode.querySelector('.chapter.preface.group[role="complementary"]').insertAdjacentHTML('beforebegin', '<div class="chapterWords">this chapter has ' + numWords + ' words (time: ' + countTime(numWords) + ')</div>');
         });
      }

      // to change options
      var changeVar = function(a) {
         // arguments : 0 name, 1 direction/increment, 2 type/limit
         var pos = getScroll() / getDocHeight();
         if (a.length > 1) {
            var cur = Variables.get()[a[0]];
            if (typeof a[2] === 'string') {
               // array of values
               let opts = a[2] === 'obj' ? Object.keys(Options[a[0]]) : Options[a[0]];
               // index out of the array, given the direction
               let end = a[1] > 0 ? opts.length : -1;
               // index of the next
               let j = opts.indexOf(cur) + a[1];
               // new value
               cur = opts[j !== end ? j : opts.length - Math.sign(a[1]) * end];
            } else {
               cur += a[1];
               // limit, given the direction
               if (Math.sign(a[1]) * cur > Math.sign(a[1]) * a[2]) cur = a[2];
            }
            Variables.set(a[0], cur);
         } else {
            Variables.reset();
         }
         setScroll(pos * getDocHeight());
      };

      // the options displayed on the page
      var options = document.createElement('div');
      options.id = 'options';
      options.className = 'options-hide';

      var opt = [
         ['previous font', '«', ['fontName', -1, 'array']],
         ['next font', '»', ['fontName', 1, 'array']],
         ['decrease font size', '-', ['fontSize', -2.5, 50]],
         ['increase font size', '+', ['fontSize', 2.5, 300]],
         ['decrease width', '&#9643;', ['padding', 1, 40]],
         ['increase width', '&#9633;', ['padding', -1, 0]],
         ['change background and color', '&#9642;', ['colors', 1, 'obj']],
         ['reset', 'r', ['reset']],
         ['show/hide menu', '&#9776;', 'show-hide']
      ];
      for (let i = 0; i < opt.length; i++) {
         let el = document.createElement('div');
         el.title = opt[i][0];
         el.innerHTML = opt[i][1];
         options.appendChild(el);
          if (opt[i][2] === 'show-hide') {
            el.addEventListener('click', function() {
               if (this.parentElement.classList.contains('options-hide')) this.parentElement.classList.remove('options-hide');
               else this.parentElement.classList.add('options-hide');
            });
         } else {
            el.addEventListener('click', function() { changeVar(opt[i][2]); });
         }
      }

      document.body.appendChild(options);

      // FULL SCREEN MODE
      workskin.insertAdjacentHTML('afterbegin', '<div class="actions fictop">' +
         '<div id="go-to-book" style="display: none;"><a>Go to Bookmark</a></div>' +
         '<div id="full-screen"><a>Full Screen</a></div>' +
         '</div>');

      document.body.insertAdjacentHTML('beforeend', '<div class="ficleft">' +
         '<a id="arrow" title="up">^</a> <a id="bookmark" title="new bookmark">+</a> ' +
         '<a id="delete-book" title="delete bookmark" style="display: none;">x</a>' +
         '</div>');

      // changes to create full screen mode
      var isFullScreen = false;
      var fullScreen = function() {
         setScroll();
         isFullScreen = true;

         addCSS(
            'ficstyle-fullscreen',
            '#outer { display: none; } ' +
            '#workskin .preface { margin: 0; padding-bottom: 0; } ' +
            '.preface h3.heading { border-width: 0; margin: .5em 0 0; } ' +
            '.actions:not(.fictop) li > a:not([href*="chapters"]) { display: none; } ' +
            '.actions:not(.fictop) { margin-top: 2em; } ' +
            'div.preface .module { padding-bottom: 0; } ' +
            '.notes-headings { cursor: pointer; border-bottom-width: 0!important; margin: 0; text-align: center; opacity: .5; } ' +
            '.notes-hidden, .notes > :not(h3):not(.userstuff):not(.jump) { display: none; } ' +
            '.module:hover .notes-hidden { display: block; position: absolute; width: 100%; max-height: 6em; font-size: .8em; transform: translateY(-100%); color: rgb(42, 42, 42); background-color: #fff; padding: 10px; box-shadow: 0 1px 2px 0 rgba(0, 0, 0, .4); margin: 0; overflow: auto; z-index: 999; cursor: pointer; } ' +
            '.preface h3 + .jump { border: 3px solid rgba(0, 0, 0, .1); border-left: 0; border-right: 0; padding: .6em; margin: 0; }'
         );

         document.body.appendChild(workskin);

         document.querySelectorAll('#workskin .preface .summary, #workskin .preface .notes').forEach(function(el) {
            let h = el.querySelector('h3');
            h.className += ' notes-headings';
            h.textContent = h.textContent.replace(':', '');
            let b = el.querySelector('.userstuff');
            let p = el.querySelector('.jump');
            if (b) {
               b.className += ' notes-hidden';
               if (p) b.appendChild(p);
            } else if (p) {
               p.className += ' notes-hidden';
            }
         });

         document.querySelector('#full-screen a').insertAdjacentText('afterbegin', 'Exit from ');
         document.querySelector('.ficleft').style.display = 'block';
         if (Bookmarks.checkIfExist()) {
            document.getElementById('delete-book').style.display = 'inline';
            document.getElementById('go-to-book').style.display = 'inline';
         }

         workskin.appendChild(document.querySelector('#feedback .actions'));
      };

		// open/close full screen mode
      document.getElementById('full-screen').addEventListener('click', function() {
         if (!isFullScreen) fullScreen();
         else window.location.reload();
      });

		// go to top
      document.getElementById('arrow').addEventListener('click', setScroll);

		// set new bookmark
      document.getElementById('bookmark').addEventListener('click', function() {
         Bookmarks.getNew();
         document.getElementById('go-to-book').style.display = 'inline';
         document.getElementById('delete-book').style.display = 'inline';
      });

		// go to the position of the bookmark
      document.getElementById('go-to-book').addEventListener('click', function() {
         setScroll(Bookmarks.checkIfExist('book'));
      });

		// delete bookmark
      document.getElementById('delete-book').addEventListener('click', function() {
         Bookmarks.cancel();
         Bookmarks.saveBooks();
         this.style.display = 'none';
         document.getElementById('go-to-book').style.display = 'none';
      });
	}
	// end fic page

})();