( function( window ) {

'use strict';

// --------------------------  -------------------------- //

function layoutModeDefinition( getSize, Outlayer ) {

  // layout mode class
  function LayoutMode( isotope ) {
    this.isotope = isotope;
    // link properties
    if ( isotope ) {
      this.options = isotope.options[ this.namespace ];
      this.element = isotope.element;
      this.items = isotope.filteredItems;
      this.size = isotope.size;
    }
  }

  /**
   * some methods should just defer to default Outlayer method
   * and reference the Isotope instance as `this`
  **/
  ( function() {
    var facadeMethods = [
      '_resetLayout',
      '_getItemLayoutPosition',
      '_manageStamp',
      '_getContainerSize',
      '_getElementOffset',
      'needsResizeLayout'
    ];

    for ( var i=0, len = facadeMethods.length; i < len; i++ ) {
      var methodName = facadeMethods[i];
      LayoutMode.prototype[ methodName ] = getOutlayerMethod( methodName );
    }

    function getOutlayerMethod( methodName ) {
      return function() {
        return Outlayer.prototype[ methodName ].apply( this.isotope, arguments );
      };
    }
  })();

  // -----  ----- //

  // for horizontal layout modes, check vertical size
  LayoutMode.prototype.needsVerticalResizeLayout = function() {
    // don't trigger if size did not change
    var size = getSize( this.isotope.element );
    // check that this.size and size are there
    // IE8 triggers resize on body size change, so they might not be
    var hasSizes = this.isotope.size && size;
    return hasSizes && size.innerHeight !== this.isotope.size.innerHeight;
  };

  // ----- measurements ----- //

  LayoutMode.prototype._getMeasurement = function() {
    this.isotope._getMeasurement.apply( this, arguments );
  };

  LayoutMode.prototype.getColumnWidth = function() {
    this.getSegmentSize( 'column', 'Width' );
  };

  LayoutMode.prototype.getRowHeight = function() {
    this.getSegmentSize( 'row', 'Height' );
  };

  /**
   * get columnWidth or rowHeight
   * segment: 'column' or 'row'
   * size 'Width' or 'Height'
  **/
  LayoutMode.prototype.getSegmentSize = function( segment, size ) {
    var segmentName = segment + size;
    var outerSize = 'outer' + size;
    // columnWidth / outerWidth // rowHeight / outerHeight
    this._getMeasurement( segmentName, outerSize );
    // got rowHeight or columnWidth, we can chill
    if ( this[ segmentName ] ) {
      return;
    }
    // fall back to item of first element
    var firstItemSize = this.getFirstItemSize();
    this[ segmentName ] = firstItemSize && firstItemSize[ outerSize ] ||
      // or size of container
      this.isotope.size[ 'inner' + size ];
  };

  LayoutMode.prototype.getFirstItemSize = function() {
    var firstItem = this.isotope.filteredItems[0];
    return firstItem && firstItem.element && getSize( firstItem.element );
  };

  // ----- methods that should reference isotope ----- //

  LayoutMode.prototype.layout = function() {
    this.isotope.layout.apply( this.isotope, arguments );
  };

  LayoutMode.prototype.getSize = function() {
    this.isotope.getSize();
    this.size = this.isotope.size;
  };

  // -------------------------- create -------------------------- //

  LayoutMode.modes = {};

  LayoutMode.create = function( namespace, options ) {

    function Mode() {
      LayoutMode.apply( this, arguments );
    }

    Mode.prototype = new LayoutMode();

    // default options
    if ( options ) {
      Mode.options = options;
    }

    Mode.prototype.namespace = namespace;
    // register in Isotope
    LayoutMode.modes[ namespace ] = Mode;

    return Mode;
  };


  return LayoutMode;

}

if ( typeof define === 'function' && define.amd ) {
  // AMD
  define( [
      'get-size/get-size',
      'outlayer/outlayer'
    ],
    layoutModeDefinition );
} else if ( typeof exports === 'object' ) {
  // CommonJS
  module.exports = layoutModeDefinition(
    require('get-size'),
    require('outlayer')
  );
} else {
  // browser global
  window.Isotope = window.Isotope || {};
  window.Isotope.LayoutMode = layoutModeDefinition(
    window.getSize,
    window.Outlayer
  );
}


})( window );