/*
 * share-selection: Medium like popover menu to share on Twitter or by email any text selected on the page 
 *
 * -- Requires jQuery --
 * -- AMD compatible  --
 *
 * Author: Xavier Damman (@xdamman)
 * GIT: https://github.com/xdamman/share-selection
 * MIT License
 */

(function($) {

  var SelectionSharer = function(options) {

    var self = this;

    options = options || {};
    if(typeof options == 'string')
        options = { elements: options };

    this.sel = null;
    this.textSelection='';
    this.htmlSelection='';


    this.getSelectionText = function(sel) {
        var html = "", text = "";
        var sel = sel || window.getSelection();
        if (sel.rangeCount) {
            var container = document.createElement("div");
            for (var i = 0, len = sel.rangeCount; i < len; ++i) {
                container.appendChild(sel.getRangeAt(i).cloneContents());
            }
            text = container.textContent;
            html = container.innerHTML
        }
        self.textSelection = text;
        self.htmlSelection = html || text;
        return text;
    };

    this.selectionDirection = function(selection) {
      var sel = selection || window.getSelection();
      var range = document.createRange();
      if(!sel.anchorNode) return 0;
      range.setStart(sel.anchorNode, sel.anchorOffset);
      range.setEnd(sel.focusNode, sel.focusOffset);
      var direction = (range.collapsed) ? "backward" : "forward";
      range.detach();
      return direction;
    };

    this.showPopunder = function() {
      self.popunder = self.popunder || document.getElementById('selectionSharerPopunder'); 

      var sel = window.getSelection(); 
      var selection = self.getSelectionText(sel);

      if(sel.isCollapsed || selection.length < 10 || !selection.match(/ /))
        return self.hidePopunder();

      if(self.popunder.classList.contains("fixed"))
        return self.popunder.style.bottom = 0;

      var range = sel.getRangeAt(0);
      var node = range.endContainer.parentNode; // The <p> where the selection ends

      // If the popunder is currently displayed
      if(self.popunder.classList.contains('show')) { 
        // If the popunder is already at the right place, we do nothing
        if(Math.ceil(self.popunder.getBoundingClientRect().top) == Math.ceil(node.getBoundingClientRect().bottom))
          return;

        // Otherwise, we first hide it and the we try again
        return self.hidePopunder(self.showPopunder);
      }

      if(node.nextElementSibling) {
        // We need to push down all the following siblings 
        self.pushSiblings(node);
      }
      else {
        // We need to append a new element to push all the content below 
        if(!self.placeholder) {
          self.placeholder = document.createElement('div');
          self.placeholder.className = 'selectionSharerPlaceholder';
        }
       
        // If we add a div between two <p> that have a 1em margin, the space between them
        // will become 2x 1em. So we give the placeholder a negative margin to avoid that
        var margin = window.getComputedStyle(node).marginBottom;
        self.placeholder.style.height = margin;
        self.placeholder.style.marginBottom = (-2 * parseInt(margin,10))+'px';
        node.parentNode.insertBefore(self.placeholder);
      }

      // scroll offset
      var offsetTop = window.pageYOffset + node.getBoundingClientRect().bottom;
      self.popunder.style.top = Math.ceil(offsetTop)+'px';

      setTimeout(function() {
        if(self.placeholder) self.placeholder.classList.add('show');
        self.popunder.classList.add('show');
      },0);

    };

    this.pushSiblings = function(el) {
      while(el=el.nextElementSibling) { el.classList.add('selectionSharer'); el.classList.add('moveDown'); }
    };

    this.hidePopunder = function(cb) {
      cb = cb || function() {};

      if(self.popunder == "fixed") {
        self.popunder.style.bottom = '-50px';
        return cb();
      }

      self.popunder.classList.remove('show');
      if(self.placeholder) self.placeholder.classList.remove('show');
      // We need to push back up all the siblings
      var els = document.getElementsByClassName('moveDown');
      while(el=els[0]) {
          el.classList.remove('moveDown');
      }

      // CSS3 transition takes 0.6s
      setTimeout(function() {
        if(self.placeholder) document.body.insertBefore(self.placeholder);
        cb();
      }, 600);

    };

    this.show = function(e) {
      setTimeout(function() {
        var sel = window.getSelection(); 
        var selection = self.getSelectionText(sel);
        if(!sel.isCollapsed && selection && selection.length>10 && selection.match(/ /)) {
          var range = sel.getRangeAt(0);
          var topOffset = range.getBoundingClientRect().top - 5;
          var top = topOffset + window.scrollY - self.$popover.height();
          var left = 0;
          if(e) {
            left = e.pageX;
          }
          else {
            var obj = sel.anchorNode.parentNode;
            left += obj.offsetWidth / 2;
            do {
              left += obj.offsetLeft;
            }
            while(obj = obj.offsetParent);
          }
          switch(self.selectionDirection(sel)) {
            case 'forward':
              left -= self.$popover.width();
              break;
            case 'backward':
              left += self.$popover.width();
              break;
            default:
              return;
          }
          self.$popover.removeClass("anim").css("top", top+10).css("left", left).show();
          setTimeout(function() {
            self.$popover.addClass("anim").css("top", top);
          }, 0);
        }
      }, 10);
    };

    this.hide = function(e) {
      self.$popover.hide();
    };

    this.smart_truncate = function(str, n){
        if (!str || !str.length) return str;
        var toLong = str.length>n,
            s_ = toLong ? str.substr(0,n-1) : str;
        s_ = toLong ? s_.substr(0,s_.lastIndexOf(' ')) : s_;
        return  toLong ? s_ +'...' : s_;
    };

    this.getRelatedTwitterAccounts = function() {
      var usernames = [];

      var creator = $('meta[name="twitter:creator"]').attr("content") || $('meta[name="twitter:creator"]').attr("value");
      if(creator) usernames.push(creator);


      // We scrape the page to find a link to http(s)://twitter.com/username
      var anchors = document.getElementsByTagName('a');
      for(var i=0, len=anchors.length;i<len;i++) { 
        if(anchors[i].attributes.href && typeof anchors[i].attributes.href.value == 'string') {
          var matches = anchors[i].attributes.href.value.match(/^https?:\/\/twitter\.com\/([a-z0-9_]{1,20})/i) 
          if(matches && matches.length > 1 && ['widgets','intent'].indexOf(matches[1])==-1)
            usernames.push(matches[1]); 
        } 
      }

      if(usernames.length > 0)
        return usernames.join(',');
      else
        return '';
    };

    this.shareTwitter = function(e) {
      e.preventDefault(); 

      if(!self.viaTwitterAccount) {
        self.viaTwitterAccount = $('meta[name="twitter:site"]').attr("content") || $('meta[name="twitter:site"]').attr("value") || "";
        self.viaTwitterAccount = self.viaTwitterAccount.replace(/@/,'');
      }

      if(!self.relatedTwitterAccounts) {
        self.relatedTwitterAccounts = self.getRelatedTwitterAccounts();
      }

      var text = "“"+self.smart_truncate(self.textSelection.trim(), 90)+"”";
	  var url_noticia = $("#url_noticia_twitter").val();
      var url = 'http://twitter.com/intent/tweet?text='+encodeURIComponent(text)+'&url='+url_noticia;

      // We only show the via @twitter:site if we have enough room
      //if(self.viaTwitterAccount && text.length < (120-6-self.viaTwitterAccount.length))
      url += '&via='+self.viaTwitterAccount;

      var w = 640, h=440;
      var left = (screen.width/2)-(w/2);
      var top = (screen.height/2)-(h/2)-100;
      window.open(url, "share_twitter", 'toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=no, resizable=no, copyhistory=no, width='+w+', height='+h+',       top='+top+', left='+left);
      self.hide();
      return false;
    };
	
	this.shareFacebook = function(e) {
      var text = self.htmlSelection.replace(/<p[^>]*>/ig,'\n').replace(/<\/p>|  /ig,'').trim();
      
      self.hide();
      return true;
    };
	
    this.render = function() {
	  var url_noticia_facebook = $("#url_noticia_facebook").val();
	  var evento_facebook = "javascript:window.open(this.href,'','width=600,height=450,resizable=NO,scrollbars=NO,top=100,left=300'); return false;";
      var popoverHTML =  '<div class="selectionSharer" id="selectionSharerPopover" style="position:absolute;">'
                       + '  <div id="selectionSharerPopover-inner"> <p class="title-share"> Compartilhe </p>'
                       + '    <ul>'
                       + '      <li><a class="action tweet" href="" title="Compartilhe esta seleção no Twitter" target="_blank"></a></li>'
                       + '      <li><a class="action facebook" href=https://www.facebook.com/sharer/sharer.php?u='+url_noticia_facebook+' title="Compartilhe esta seleção no Facebook" onclick="'+evento_facebook+'"></a></li>'
					   + '    </ul>'
                       + '  </div>'
                       + '  <div class="selectionSharerPopover-clip"><span class="selectionSharerPopover-arrow"></span></div>'
                       + '</div>';

      var popunderHTML = '<div id="selectionSharerPopunder" class="selectionSharer">'
                       + '  <div id="selectionSharerPopunder-inner">'
                       + '    <label>Share this selection</label>'
                       + '    <ul>'
                       + '      <li><a class="action tweet" href="" title="Share this selection on Twitter" target="_blank">Tweet</a></li>'
                       + '      <li><a class="action facebook" href="" title="Compartilhe esta seleção no Facebook" target="_blank">Facebook</a></li>'
					   + '    </ul>'
                       + '  </div>'
                       + '</div>';

      self.$popover = $(popoverHTML);
      self.$popover.find('a.tweet').click(self.shareTwitter);

      $('body').append(self.$popover);

      self.$popunder = $(popunderHTML);
      self.$popunder.find('a.tweet').click(self.shareTwitter);
      $('body').append(self.$popunder);
    };

    this.setElements = function(elements) {
      if(typeof elements == 'string') elements = $(elements);
      self.$elements = elements instanceof $ ? elements : $(elements);
      self.$elements.mouseup(self.show).mousedown(self.hide).addClass("selectionShareable");

      self.$elements.bind('touchstart', function(e) {
        self.isMobile = true;
      });

      document.onselectionchange = self.selectionChanged;
    };

    this.selectionChanged = function(e) {
      if(!self.isMobile) return;

      if(self.lastSelectionChanged) {
        clearTimeout(self.lastSelectionChanged);
      }
      self.lastSelectionChanged = setTimeout(function() {
        self.showPopunder(e);
      }, 300);
    };

    this.render();

    if(options.elements) {
      this.setElements(options.elements);
    }

  };

  // jQuery plugin 
  // Usage: $( "p" ).selectionSharer();
  $.fn.selectionSharer = function() {
    var sharer = new SelectionSharer();
    sharer.setElements(this);
    return this; 
  };

  // For AMD / requirejs
  // Usage: require(["selection-sharer!"]); 
  //     or require(["selection-sharer"], function(selectionSharer) { var sharer = new SelectionSharer('p'); });
  if(typeof define == 'function') {
    define(function() { 
      SelectionSharer.load = function (name, req, onLoad, config) {
        var sharer = new SelectionSharer();
        sharer.setElements('p');
        onLoad();
      };
      return SelectionSharer; 
    });

  }
  else {
    // Registering SelectionSharer as a global
    // Usage: var sharer = new SelectionSharer('p');
    window.SelectionSharer = SelectionSharer;
  }
  
})(jQuery);