(function ($) {
  'use strict';
  var $body = $('body'),
    $window = $(window),
    $document = $(document);

  // debouncing function from John Hann
  // http://unscriptable.com/index.php/2009/03/20/debouncing-javascript-methods/
  function debounce(func, threshold, execAsap) {
    var timeout;

    return function debounced() {
      var obj = this, args = arguments;
      function delayed() {
        if (!execAsap)
          func.apply(obj, args);
        timeout = null;
      };

      if (timeout)
        clearTimeout(timeout);
      else if (execAsap)
        func.apply(obj, args);

      timeout = setTimeout(delayed, threshold || 100);
    };
  };

  // Throttle http://sampsonblog.com/simple-throttle-function/
  function throttle(callback, limit) {
    var tick = false;
    return function () {
      if (!tick) {
        callback.call();
        tick = true;
        setTimeout(function () {
          tick = false;
        }, limit);
      }
    }
  }

  function throttleRaf (callback) {
    var tick = false;
    return function () {
      if (!tick) {
        window.requestAnimationFrame(function(){
          callback.call();
          tick = false;
        });
        tick = true;
      }
    }
  }
  // smartscroll with throttle
  $.fn['smartscroll'] = function (fn) {
    return fn ? this.bind('scroll', throttleRaf(fn)) : this.trigger('smartscroll');
  };

  // offcanvas menu
  function offCanvasNav() {
    var isSmoothScrollSupported = 'scrollBehavior' in document.documentElement.style,
        isScrollToOptionsSupported = (function() {
          var supports = false
          try {
            var div = document.createElement('div');
            div.scrollTo({
              top: 0,
              get behavior () {
                supports = true
                return 'smooth'
              }
            });
          } catch (err) {}
          return supports
        })();

    var $offCanvasCollapse = $('.offcanvas-collapse'),
        $navbarCollapse = $('.site-header .navbar-collapse');

    function scrollToTop() {
      if (isSmoothScrollSupported && isScrollToOptionsSupported) {
        // jump if needed
        if (window.scrollY > 300) {
          window.scrollTo(0, 300);
        }
        
        // and smooth scroll
        window.scrollTo({
          top: 0,
          left: 0,
          behavior: 'smooth'
        });
      } else {
        // use jquery
        $("html, body").animate({ scrollTop: 0 }, "fast");
      }     
    }

    // open offcanvas menu
    function offcanvasOpen() {
      $offCanvasCollapse.addClass('open');
      $body.addClass('offcanvas-active');
      scrollToTop();
    }

    // close offcanvas menu
    function offcanvasClose() {
      $offCanvasCollapse.removeClass('open');
      $body.removeClass('offcanvas-active')
        .addClass('offcanvas-deactivating');

      window.setTimeout(function () {
        $body.removeClass('offcanvas-deactivating');
      }, 300);

      scrollToTop();
    }

    function offcanvasIsOpened() {
      return ($body.hasClass('offcanvas-active'));
    }

    function offcanvasToggle() {
      if (offcanvasIsOpened()) {
        offcanvasClose();
      } else {
        offcanvasOpen();
      }
    }

    // add mobile menu logo
    $('.site-header .site-title')
      .clone()
      .prependTo($navbarCollapse);

    // add mobile menu close
    $navbarCollapse.append('<a href="#" class="offcanvas-close" data-toggle="offcanvas">Close</a>');

    // add close overlay
    $('.outer-wrapper').append('<div class="outer-wrapper-overlay" data-toggle="offcanvas"></div>');

    $('[data-toggle="offcanvas"]').on('click', function () {
      offcanvasToggle();
    });

  }

  // sticky top nav
  function stickyNav() {
    var scrollTop = 0,
      navbarHeight = 80;
    $window.smartscroll(function () {
      scrollTop = $window.scrollTop();

      if (scrollTop >= navbarHeight) {
        $body.addClass('scrolled');
      } else {
        $body.removeClass('scrolled');
      }
    });
  }

  // search menu expand/collapsing functionality
  function searchNav() {
    var $navItemSearch = $('.nav-item-search'),
      // $searchField = $navItemSearch.find('.search-field'),
      $toggle;
    if ($navItemSearch.length) {
      $toggle = $('<a class="nav-item-search-toggle" href="#">Toggle</a>').appendTo($navItemSearch);
      $toggle.on('click', function (ev) {
        $navItemSearch.toggleClass('expand');
        $('.search-field').focus();
        ev.preventDefault();
      });

      $('.search-field, .search-submit').on('blur', function () {
        window.requestAnimationFrame(function () {
          var isFocus = $('.search-submit').is(':focus');
          if (!isFocus) {
            $navItemSearch.removeClass('expand');
          }
        });
      });
    }
  }

  $document.ready(function () {
    offCanvasNav();
    stickyNav();
    searchNav();
  });
}(jQuery));