// TODO: refactor me!
var sourceVisible = localStorage.getItem('source-visible') === 'true';

(function ($) {
  addOriginalToggler();
  addSpacingBetweenCnAndEn();

  function addOriginalToggler() {
    var nodes = document.querySelectorAll('p, li, h1, h2, h3, h4, h5, h6, header, a, button, small');
    _.each(nodes, function (node) {
      var $node = $(node);

      if (isLink(node) || isButton(node)) {
        $node.on('click', function (event) {
          event.stopPropagation();
        });

        if (/^http?s:\/\//.test($node.attr('href')) && !$node.attr('target')) {
          $node.attr('target', '_blank');
        }
      }

      var prevNode = node.previousElementSibling;
      var $prevNode = $(prevNode);

      if (!prevNode) {
        return;
      }

      if (isTranslationResult(node, prevNode)) {
        if ($prevNode.hasClass('nav-list-item')) {
          return;
        }
        if (isPureEnglish($node.text()) && $node.text() !== $prevNode.text()) {
          return;
        }

        if (isPureEnglish($prevNode.text())) {
          $node.attr('id', prevNode.id);
          $node.addClass('translated');
          $node.addClass('translated-cn');
          $prevNode.removeAttr('id');
          $prevNode.addClass('original-english');
          if (!sourceVisible) {
            $prevNode.addClass('hidden');
          }
          if (!isLink(node) && !isButton(node)) {
            var isDragging = false;
            $node.on('mousedown', function(){
                $(window).on('mousemove', function(){
                    isDragging = true;
                    $(window).unbind('mousemove');
                });
            });
            $prevNode.on('mousedown', function(){
                $(window).on('mousemove', function(){
                    isDragging = true;
                    $(window).unbind('mousemove');
                });
            });
            $node.on('mouseup', function () {
              var wasDragging = isDragging;
              isDragging = false;
              $(window).unbind('mousemove');
              if(!wasDragging){
                $prevNode.toggleClass('hidden');
              }
            });
            $prevNode.on('mouseup', function () {
              var wasDragging = isDragging;
              isDragging = false;
              $(window).unbind('mousemove');
              if(!wasDragging){
                $prevNode.addClass('hidden');
              }
            });
          }
          $node.after($prevNode);
        }
      }
    });
  }

  function addSpacingBetweenCnAndEn($node) {
    var nodes = document.querySelectorAll('.translated-cn');
    _.each(nodes, function (node) {
      var text = node.innerHTML;
      text = text.replace(/([\x20-\xff]+)/g, function (word) {
        if (!word.replace(/\s/, '')) {
          return '';
        } else if (/<[^>]*>/.test(word)) {
          return ' ' + word + ' ';
        } else {
          return ' ' + word + ' ';
        }
      });
      node.innerHTML = text;
    });
  }

  function isLink(node) {
    return node.tagName.toUpperCase() === 'A';
  }

  function isButton(node) {
    return node.tagName.toUpperCase() === 'BUTTON';
  }

  function isPureEnglish(text) {
    // accept &mdash; , quotes, ® and façade too.
    text = text.replace('在线例子', '');
    return /^[\1-\255—’“”ç®…à]*$/.test(text);
  }

  function attributesToString(node) {
    return _.chain(node.attributes)
      .map(function (value) {
        if (value.name === 'id') {
          return '';
        } else {
          return value.name + '=' + value.value;
        }
      })
      .sortBy()
      .value()
      .join(';');
  }

  function isClonedNode(node1, node2) {
    return node1.tagName === node2.tagName &&
      attributesToString(node1) === attributesToString(node2);
  }

  function indexOfSameType(node) {
    var i = 0;
    var aNode = node.parentNode.firstChild;
    while (aNode !== node) {
      ++i;
      if (aNode.tagName !== node.tagName) {
        i = 0;
      }
      aNode = aNode.nextElementSibling;
    }
    return i;
  }

  function isTranslationResult(node, prevNode) {
    return indexOfSameType(node) % 2 === 1 && isClonedNode(node, prevNode) && isPureEnglish(prevNode.innerText);
  }
})(angular.element);