/*jslint unparam: true, browser: true, indent: 2 */

;(function ($, window, document, undefined) {
  'use strict';

  Foundation.libs.clearing = {
    name : 'clearing',

    version : '4.0.0',

    settings : {
      templates : {
        viewing : '<a href="#" class="clearing-close">&times;</a>' +
          '<div class="visible-img" style="display: none"><img src="//:0">' +
          '<p class="clearing-caption"></p><a href="#" class="clearing-main-left"><span></span></a>' +
          '<a href="#" class="clearing-main-right"><span></span></a></div>'
      },

      // comma delimited list of selectors that, on click, will close clearing,
      // add 'div.clearing-blackout, div.visible-img' to close on background click
      close_selectors : '.clearing-close',

      // event initializers and locks
      init : false,
      locked : false
    },

    init : function (scope, method, options) {
      this.scope = this.scope || scope;
      Foundation.inherit(this, 'set_data get_data remove_data throttle');

      if (typeof method === 'object') {
        options = $.extend(true, this.settings, method);
      }

      if (typeof method != 'string') {
        $(this.scope).find('ul[data-clearing]').each(function () {
          var self = Foundation.libs.clearing,
              $el = $(this),
              options = options || {},
              settings = self.get_data($el);

          if (!settings) {
            options.$parent = $el.parent();

            self.set_data($el, $.extend(true, self.settings, options));

            self.assemble($el.find('li'));

            if (!self.settings.init) {
              self.events().swipe_events();
            }
          }
        });

        return this.settings.init;
      } else {
        // fire method
        return this[method].call(this, options);
      }
    },

    // event binding and initial setup

    events : function () {
      var self = this;

      $(this.scope)
        .on('click.fndtn.clearing', 'ul[data-clearing] li',
          function (e, current, target) {
            var current = current || $(this),
                target = target || current,
                settings = self.get_data(current.parent());

            e.preventDefault();
            if (!settings) self.init();

            // set current and target to the clicked li if not otherwise defined.
            self.open($(e.target), current, target);
            self.update_paddles(target);
          })

        .on('click.fndtn.clearing', '.clearing-main-right',
          function (e) { this.nav(e, 'next') }.bind(this))
        .on('click.fndtn.clearing', '.clearing-main-left',
          function (e) { this.nav(e, 'prev') }.bind(this))
        .on('click.fndtn.clearing', this.settings.close_selectors,
          function (e) { Foundation.libs.clearing.close(e, this) })
        .on('keydown.fndtn.clearing',
          function (e) { this.keydown(e) }.bind(this));

      $(window).on('resize.fndtn.clearing',
        function (e) { this.resize() }.bind(this));

      this.settings.init = true;
      return this;
    },

    swipe_events : function () {
      var self = this;

      $(this.scope)
        .on('touchstart.fndtn.clearing', '.visible-img', function(e) {
          var data = {
                start_page_x: e.touches[0].pageX,
                start_page_y: e.touches[0].pageY,
                start_time: (new Date()).getTime(),
                delta_x: 0,
                is_scrolling: undefined
              };

          $(this).data('swipe-transition', data);
          e.stopPropagation();
        })
        .on('touchmove.fndtn.clearing', '.visible-img', function(e) {
          // Ignore pinch/zoom events
          if(e.touches.length > 1 || e.scale && e.scale !== 1) return;

          var data = $(this).data('swipe-transition');

          if (typeof data === 'undefined') {
            data = {};
          }

          data.delta_x = e.touches[0].pageX - data.start_page_x;

          if ( typeof data.is_scrolling === 'undefined') {
            data.is_scrolling = !!( data.is_scrolling || Math.abs(data.delta_x) < Math.abs(e.touches[0].pageY - data.start_page_y) );
          }

          if (!data.is_scrolling && !data.active) {
            e.preventDefault();
            var direction = (data.delta_x < 0) ? 'next' : 'prev';
            data.active = true;
            self.nav(e, direction);
          }
        })
        .on('touchend.fndtn.clearing', '.visible-img', function(e) {
          $(this).data('swipe-transition', {});
          e.stopPropagation();
        });
    },

    assemble : function ($li) {
      var $el = $li.parent(),
          settings = this.get_data($el),
          grid = $el.detach(),
          data = {
            grid: '<div class="carousel">' + this.outerHTML(grid[0]) + '</div>',
            viewing: settings.templates.viewing
          },
          wrapper = '<div class="clearing-assembled"><div>' + data.viewing +
            data.grid + '</div></div>';

      return settings.$parent.append(wrapper);
    },

    // event callbacks

    open : function ($image, current, target) {
      var root = target.closest('.clearing-assembled'),
          container = root.find('div').first(),
          visible_image = container.find('.visible-img'),
          image = visible_image.find('img').not($image);

      if (!this.locked()) {
        // set the image to the selected thumbnail
        image.attr('src', this.load($image));

        this.loaded(image, function () {
          // toggle the gallery
          root.addClass('clearing-blackout');
          container.addClass('clearing-container');
          visible_image.show();
          this.fix_height(target)
            .caption(visible_image.find('.clearing-caption'), $image)
            .center(image)
            .shift(current, target, function () {
              target.siblings().removeClass('visible');
              target.addClass('visible');
            });
        }.bind(this));
      }
    },

    close : function (e, el) {
      e.preventDefault();

      var root = (function (target) {
            if (/blackout/.test(target.selector)) {
              return target;
            } else {
              return target.closest('.clearing-blackout');
            }
          }($(el))), container, visible_image;

      if (el === e.target && root) {
        container = root.find('div').first(),
        visible_image = container.find('.visible-img');
        this.settings.prev_index = 0;
        root.find('ul[data-clearing]')
          .attr('style', '').closest('.clearing-blackout')
          .removeClass('clearing-blackout');
        container.removeClass('clearing-container');
        visible_image.hide();
      }

      return false;
    },

    keydown : function (e) {
      var clearing = $('.clearing-blackout').find('ul[data-clearing]');

      if (e.which === 39) this.go(clearing, 'next');
      if (e.which === 37) this.go(clearing, 'prev');
      if (e.which === 27) $('a.clearing-close').trigger('click');
    },

    nav : function (e, direction) {
      var clearing = $('.clearing-blackout').find('ul[data-clearing]');

      e.preventDefault();
      this.go(clearing, direction);
    },

    resize : function () {
      var image = $('.clearing-blackout .visible-img').find('img');

      if (image.length) {
        this.center(image);
      }
    },

    // visual adjustments
    fix_height : function (target) {
      var lis = target.parent().children(),
          self = this;

      lis.each(function () {
          var li = $(this),
              image = li.find('img');

          if (li.height() > self.outerHeight(image)) {
            li.addClass('fix-height');
          }
        })
        .closest('ul')
        .width(lis.length * 100 + '%');

      return this;
    },

    update_paddles : function (target) {
      var visible_image = target
        .closest('.carousel')
        .siblings('.visible-img');

      if (target.next().length) {
        visible_image
          .find('.clearing-main-right')
          .removeClass('disabled');
      } else {
        visible_image
          .find('.clearing-main-right')
          .addClass('disabled');
      }

      if (target.prev().length) {
        visible_image
          .find('.clearing-main-left')
          .removeClass('disabled');
      } else {
        visible_image
          .find('.clearing-main-left')
          .addClass('disabled');
      }
    },

    center : function (target) {
      target.css({
        marginLeft : -(this.outerWidth(target) / 2),
        marginTop : -(this.outerHeight(target) / 2)
      });
      return this;
    },

    // image loading and preloading

    load : function ($image) {
      var href = $image.parent().attr('href');

      this.preload($image);

      if (href) return href;
      return $image.attr('src');
    },

    preload : function ($image) {
      this
        .img($image.closest('li').next())
        .img($image.closest('li').prev());
    },

    loaded : function (image, callback) {
      // based on jquery.imageready.js
      // @weblinc, @jsantell, (c) 2012

      function loaded () {
        callback();
      }

      function bindLoad () {
        this.one('load', loaded);

        if (/MSIE (\d+\.\d+);/.test(navigator.userAgent)) {
          var src = this.attr( 'src' ),
              param = src.match( /\?/ ) ? '&' : '?';

          param += 'random=' + (new Date()).getTime();
          this.attr('src', src + param);
        }
      }

      if (!image.attr('src')) {
        loaded();
        return;
      }

      if (this.complete || this.readyState === 4) {
        loaded();
      } else {
        bindLoad.call(image);
      }
    },

    img : function (img) {
      if (img.length) {
        var new_img = new Image(),
            new_a = img.find('a');

        if (new_a.length) {
          new_img.src = new_a.attr('href');
        } else {
          new_img.src = img.find('img').attr('src');
        }
      }
      return this;
    },

    // image caption

    caption : function (container, $image) {
      var caption = $image.data('caption');

      if (caption) {
        container
          .text(caption)
          .show();
      } else {
        container
          .text('')
          .hide();
      }
      return this;
    },

    // directional methods

    go : function ($ul, direction) {
      var current = $ul.find('.visible'),
          target = current[direction]();

      if (target.length) {
        target
          .find('img')
          .trigger('click', [current, target]);
      }
    },

    shift : function (current, target, callback) {
      var clearing = target.parent(),
          old_index = this.settings.prev_index || target.index(),
          direction = this.direction(clearing, current, target),
          left = parseInt(clearing.css('left'), 10),
          width = this.outerWidth(target),
          skip_shift;

      // we use jQuery animate instead of CSS transitions because we
      // need a callback to unlock the next animation
      if (target.index() !== old_index && !/skip/.test(direction)){
        if (/left/.test(direction)) {
          this.lock();
          clearing.animate({left : left + width}, 300, this.unlock());
        } else if (/right/.test(direction)) {
          this.lock();
          clearing.animate({left : left - width}, 300, this.unlock());
        }
      } else if (/skip/.test(direction)) {
        // the target image is not adjacent to the current image, so
        // do we scroll right or not
        skip_shift = target.index() - this.settings.up_count;
        this.lock();

        if (skip_shift > 0) {
          clearing.animate({left : -(skip_shift * width)}, 300, this.unlock());
        } else {
          clearing.animate({left : 0}, 300, this.unlock());
        }
      }

      callback();
    },

    direction : function ($el, current, target) {
      var lis = $el.find('li'),
          li_width = this.outerWidth(lis) + (this.outerWidth(lis) / 4),
          up_count = Math.floor(this.outerWidth($('.clearing-container')) / li_width) - 1,
          target_index = lis.index(target),
          response;

      this.settings.up_count = up_count;

      if (this.adjacent(this.settings.prev_index, target_index)) {
        if ((target_index > up_count)
          && target_index > this.settings.prev_index) {
          response = 'right';
        } else if ((target_index > up_count - 1)
          && target_index <= this.settings.prev_index) {
          response = 'left';
        } else {
          response = false;
        }
      } else {
        response = 'skip';
      }

      this.settings.prev_index = target_index;

      return response;
    },

    adjacent : function (current_index, target_index) {
      for (var i = target_index + 1; i >= target_index - 1; i--) {
        if (i === current_index) return true;
      }
      return false;
    },

    // lock management

    lock : function () {
      this.settings.locked = true;
    },

    unlock : function () {
      this.settings.locked = false;
    },

    locked : function () {
      return this.settings.locked;
    },

    // plugin management/browser quirks

    outerHTML : function (el) {
      // support FireFox < 11
      return el.outerHTML || new XMLSerializer().serializeToString(el);
    },

    off : function () {
      $(this.scope).off('.fndtn.clearing');
      $(window).off('.fndtn.clearing');
      this.remove_data(); // empty settings cache
      this.settings.init = false;
    }
  };

}(Foundation.zj, this, this.document));
