(function() {
    "use strict";

    var doc = document;

    var group = {
        // Detect and change the top position of the cycle navs
        cycleFix: function() {
          if( doc.querySelectorAll( ".group-post-banner-image").length >= 1 ) {
              var imgs = doc.querySelectorAll( ".group-post-banner-image" ),
                  imgHeight = imgs[ 0 ].clientHeight,
                  cycleNav = doc.querySelectorAll( ".cycle-nav" ),
                  cycleNavHeight = cycleNav[ 0 ].clientHeight,
                  len = cycleNav.length,
                  i = -1;

              // Hide the navs when there's noly one slide
              if( imgs.length <= 1 ) {
                  for( i = 0; i < len; i++ ) {
                      cycleNav[ i ].classList.add( "hide" );
                  }
              } else {
              // Change nav top positions which are calculating by JavaScript
                  for ( i = 0; i < len; i++ ) {
                      cycleNav[ i ].style.top = ( ( imgHeight / 2 ) - ( cycleNavHeight / 2 ) )  + "px";
                  }
              }
          }
        },
        // Create the tool tip wrap and get the seen counts and then inject them into DOM
        createToolTip: function() {
          if( doc.querySelectorAll( ".group-post-seen-by-name" ).length >= 1 ) {
              var container = doc.querySelector( ".group-post-seen-by" ),
                  names = doc.querySelectorAll( ".group-post-seen-by-name" ),
                  namesLen = names.length,
                  span = doc.createElement( "span" ),
                  wrap = doc.createElement( "div" ),
                  frag = document.createDocumentFragment();

              // Get the seen counts and append them
              span.className = "group-post-seen-by-count";
              span.textContent = namesLen;
              names[ 0 ].parentNode.appendChild( span );

              // Create the tool tip and save them in the document fragment
              wrap.className = "group-post-seen-by-names tool-tip";
              Array.prototype.slice.call( names ).forEach( function( el ) {
                  frag.appendChild( el );
              });

              // Append the final result to DOM
              wrap.appendChild( frag );
              container.appendChild( wrap );
          }
        },
        scrollEffect: function() {
            var page = doc.querySelector( ".group-page" ),
                wrap = doc.querySelector( ".group-page-banner-image-wrap" ),
                scrollClass = "scroll";

            function stickyScroll( e ) {
              if( window.pageYOffset > 210 ) {
                  page.classList.add( scrollClass );
              }
            }

            window.addEventListener( "scroll", stickyScroll);
        }
    }

    // When DOM is completely loaded
    document.addEventListener( "DOMContentLoaded", function( event ) {
        group.cycleFix();  
        group.createToolTip();
        group.scrollEffect();
    });

})();