function pswp(container, element, trigger, caption, isGallery) {
  var parseThumbnailElements = function (el) {
    var items = [],
      gridEl,
      linkEl,
      item;

    $(el)
      .find(element)
      .each(function (i, v) {
        gridEl = $(v);
        linkEl = gridEl.find(trigger);

        item = {
          src: isGallery
            ? gridEl.find('img').attr('src')
            : linkEl.attr('href'),
          w: 0,
          h: 0,
        };

        if (caption && gridEl.find(caption).length) {
          item.title = gridEl.find(caption).html();
        }

        items.push(item);
      });

    return items;
  };

  var openPhotoSwipe = function (index, galleryElement) {
    var pswpElement = document.querySelectorAll('.pswp')[0],
      gallery,
      options,
      items;

    items = parseThumbnailElements(galleryElement);

    options = {
      closeOnScroll: false,
      history: false,
      index: index,
      shareEl: false,
      showAnimationDuration: 0,
      showHideOpacity: true,
    };

    gallery = new PhotoSwipe(
      pswpElement,
      PhotoSwipeUI_Default,
      items,
      options
    );

    gallery.listen('gettingData', function (index, item) {
      if (item.w < 1 || item.h < 1) {
        var img = new Image();
        img.onload = function () {
          item.w = this.width;
          item.h = this.height;
          gallery.updateSize(true);
        };
        img.src = item.src;
      }
    });
    gallery.init();
  };

  var onThumbnailsClick = function (e) {
    e.preventDefault();

    var index = $(e.target)
      .closest(container)
      .find(element)
      .index($(e.target).closest(element));
    var clickedGallery = $(e.target).closest(container);

    openPhotoSwipe(index, clickedGallery[0]);

    return false;
  };

  $(container).on('click', trigger, function (e) {
    onThumbnailsClick(e);
  });
}

function feed() {
  'use strict';

  var grid = document.querySelector('.post-feed');
  if (!grid) return;

  var masonry;

  imagesLoaded(grid, function () {
    masonry = new Masonry(grid, {
      itemSelector: '.grid-item',
      columnWidth: '.grid-sizer',
      hiddenStyle: { transform: 'translateY(50px)', opacity: 0 },
      visibleStyle: { transform: 'translateY(0)', opacity: 1 },
    });

    masonry.on('layoutComplete', function () {
      grid.classList.add('initialized');
    });

    masonry.layout();

    function callback(items, loadNextPage) {
      imagesLoaded(items, function (loaded) {
        masonry.appended(items);
        masonry.layout();
        loaded.elements.forEach(function (item) {
          item.style.visibility = 'visible';
        });
        loadNextPage();
      });
    }

    pagination(true, callback, true);
  });

  pswp(
    '.post-feed',
    '.post',
    '.post-lightbox',
    '.post-caption',
    false
  );
}

feed();