/*!
 * imagesLoaded v4.1.0
 * JavaScript is all like "You images are done yet or what?"
 * MIT License
 */

"use strict";
( function( window, factory ) { 'use strict';
  // universal module definition

  /*global define: false, module: false, require: false */

  if ( typeof define == 'function' && define.amd ) {
    // AMD
    define( [
      'ev-emitter/ev-emitter'
    ], function( EvEmitter ) {
      return factory( window, EvEmitter );
    });
  } else if ( typeof module == 'object' && module.exports ) {
    // CommonJS
    module.exports = factory(
      window,
      require('ev-emitter')
    );
  } else {
    // browser global
    window.imagesLoaded = factory(
      window,
      window.EvEmitter
    );
  }

})( window,

// --------------------------  factory -------------------------- //

function factory( window, EvEmitter ) {

'use strict';

var $ = window.jQuery;
var console = window.console;

// -------------------------- helpers -------------------------- //

// extend objects
function extend( a, b ) {
  for ( var prop in b ) {
    a[ prop ] = b[ prop ];
  }
  return a;
}

// turn element or nodeList into an array
function makeArray( obj ) {
  var ary = [];
  if ( Array.isArray( obj ) ) {
    // use object if already an array
    ary = obj;
  } else if ( typeof obj.length == 'number' ) {
    // convert nodeList to array
    for ( var i=0; i < obj.length; i++ ) {
      ary.push( obj[i] );
    }
  } else {
    // array of single index
    ary.push( obj );
  }
  return ary;
}

// -------------------------- imagesLoaded -------------------------- //

/**
 * @param {Array, Element, NodeList, String} elem
 * @param {Object or Function} options - if function, use as callback
 * @param {Function} onAlways - callback function
 */
function ImagesLoaded( elem, options, onAlways ) {
  // coerce ImagesLoaded() without new, to be new ImagesLoaded()
  if ( !( this instanceof ImagesLoaded ) ) {
    return new ImagesLoaded( elem, options, onAlways );
  }
  // use elem as selector string
  if ( typeof elem == 'string' ) {
    elem = document.querySelectorAll( elem );
  }

  this.elements = makeArray( elem );
  this.options = extend( {}, this.options );

  if ( typeof options == 'function' ) {
    onAlways = options;
  } else {
    extend( this.options, options );
  }

  if ( onAlways ) {
    this.on( 'always', onAlways );
  }

  this.getImages();

  if ( $ ) {
    // add jQuery Deferred object
    this.jqDeferred = new $.Deferred();
  }

  // HACK check to allow time to bind listeners
  setTimeout( function() {
    this.check();
  }.bind( this ));
}

ImagesLoaded.prototype = Object.create( EvEmitter.prototype );

ImagesLoaded.prototype.options = {};

ImagesLoaded.prototype.getImages = function() {
  this.images = [];

  // filter & find items if we have an item selector
  this.elements.forEach( this.addElementImages, this );
};

/**
 * @param {Node} element
 */
ImagesLoaded.prototype.addElementImages = function( elem ) {
  // filter siblings
  if ( elem.nodeName == 'IMG' ) {
    this.addImage( elem );
  }
  // get background image on element
  if ( this.options.background === true ) {
    this.addElementBackgroundImages( elem );
  }

  // find children
  // no non-element nodes, #143
  var nodeType = elem.nodeType;
  if ( !nodeType || !elementNodeTypes[ nodeType ] ) {
    return;
  }
  var childImgs = elem.querySelectorAll('img');
  // concat childElems to filterFound array
  for ( var i=0; i < childImgs.length; i++ ) {
    var img = childImgs[i];
    this.addImage( img );
  }

  // get child background images
  if ( typeof this.options.background == 'string' ) {
    var children = elem.querySelectorAll( this.options.background );
    for ( i=0; i < children.length; i++ ) {
      var child = children[i];
      this.addElementBackgroundImages( child );
    }
  }
};

var elementNodeTypes = {
  1: true,
  9: true,
  11: true
};

ImagesLoaded.prototype.addElementBackgroundImages = function( elem ) {
  var style = getComputedStyle( elem );
  if ( !style ) {
    // Firefox returns null if in a hidden iframe https://bugzil.la/548397
    return;
  }
  // get url inside url("...")
  var reURL = /url\((['"])?(.*?)\1\)/gi;
  var matches = reURL.exec( style.backgroundImage );
  while ( matches !== null ) {
    var url = matches && matches[2];
    if ( url ) {
      this.addBackground( url, elem );
    }
    matches = reURL.exec( style.backgroundImage );
  }
};

/**
 * @param {Image} img
 */
ImagesLoaded.prototype.addImage = function( img ) {
  var loadingImage = new LoadingImage( img );
  this.images.push( loadingImage );
};

ImagesLoaded.prototype.addBackground = function( url, elem ) {
  var background = new Background( url, elem );
  this.images.push( background );
};

ImagesLoaded.prototype.check = function() {
  var _this = this;
  this.progressedCount = 0;
  this.hasAnyBroken = false;
  // complete if no images
  if ( !this.images.length ) {
    this.complete();
    return;
  }

  function onProgress( image, elem, message ) {
    // HACK - Chrome triggers event before object properties have changed. #83
    setTimeout( function() {
      _this.progress( image, elem, message );
    });
  }

  this.images.forEach( function( loadingImage ) {
    loadingImage.once( 'progress', onProgress );
    loadingImage.check();
  });
};

ImagesLoaded.prototype.progress = function( image, elem, message ) {
  this.progressedCount++;
  this.hasAnyBroken = this.hasAnyBroken || !image.isLoaded;
  // progress event
  this.emitEvent( 'progress', [ this, image, elem ] );
  if ( this.jqDeferred && this.jqDeferred.notify ) {
    this.jqDeferred.notify( this, image );
  }
  // check if completed
  if ( this.progressedCount == this.images.length ) {
    this.complete();
  }

  if ( this.options.debug && console ) {
    console.log( 'progress: ' + message, image, elem );
  }
};

ImagesLoaded.prototype.complete = function() {
  var eventName = this.hasAnyBroken ? 'fail' : 'done';
  this.isComplete = true;
  this.emitEvent( eventName, [ this ] );
  this.emitEvent( 'always', [ this ] );
  if ( this.jqDeferred ) {
    var jqMethod = this.hasAnyBroken ? 'reject' : 'resolve';
    this.jqDeferred[ jqMethod ]( this );
  }
};

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

function LoadingImage( img ) {
  this.img = img;
}

LoadingImage.prototype = Object.create( EvEmitter.prototype );

LoadingImage.prototype.check = function() {
  // If complete is true and browser supports natural sizes,
  // try to check for image status manually.
  var isComplete = this.getIsImageComplete();
  if ( isComplete ) {
    // report based on naturalWidth
    this.confirm( this.img.naturalWidth !== 0, 'naturalWidth' );
    return;
  }

  // If none of the checks above matched, simulate loading on detached element.
  this.proxyImage = new Image();
  this.proxyImage.addEventListener( 'load', this );
  this.proxyImage.addEventListener( 'error', this );
  // bind to image as well for Firefox. #191
  this.img.addEventListener( 'load', this );
  this.img.addEventListener( 'error', this );
  this.proxyImage.src = this.img.src;
};

LoadingImage.prototype.getIsImageComplete = function() {
  return this.img.complete && this.img.naturalWidth !== undefined;
};

LoadingImage.prototype.confirm = function( isLoaded, message ) {
  this.isLoaded = isLoaded;
  this.emitEvent( 'progress', [ this, this.img, message ] );
};

// ----- events ----- //

// trigger specified handler for event type
LoadingImage.prototype.handleEvent = function( event ) {
  var method = 'on' + event.type;
  if ( this[ method ] ) {
    this[ method ]( event );
  }
};

LoadingImage.prototype.onload = function() {
  this.confirm( true, 'onload' );
  this.unbindEvents();
};

LoadingImage.prototype.onerror = function() {
  this.confirm( false, 'onerror' );
  this.unbindEvents();
};

LoadingImage.prototype.unbindEvents = function() {
  this.proxyImage.removeEventListener( 'load', this );
  this.proxyImage.removeEventListener( 'error', this );
  this.img.removeEventListener( 'load', this );
  this.img.removeEventListener( 'error', this );
};

// -------------------------- Background -------------------------- //

function Background( url, element ) {
  this.url = url;
  this.element = element;
  this.img = new Image();
}

// inherit LoadingImage prototype
Background.prototype = Object.create( LoadingImage.prototype );

Background.prototype.check = function() {
  this.img.addEventListener( 'load', this );
  this.img.addEventListener( 'error', this );
  this.img.src = this.url;
  // check if image is already complete
  var isComplete = this.getIsImageComplete();
  if ( isComplete ) {
    this.confirm( this.img.naturalWidth !== 0, 'naturalWidth' );
    this.unbindEvents();
  }
};

Background.prototype.unbindEvents = function() {
  this.img.removeEventListener( 'load', this );
  this.img.removeEventListener( 'error', this );
};

Background.prototype.confirm = function( isLoaded, message ) {
  this.isLoaded = isLoaded;
  this.emitEvent( 'progress', [ this, this.element, message ] );
};

// -------------------------- jQuery -------------------------- //

ImagesLoaded.makeJQueryPlugin = function( jQuery ) {
  jQuery = jQuery || window.jQuery;
  if ( !jQuery ) {
    return;
  }
  // set local variable
  $ = jQuery;
  // $().imagesLoaded()
  $.fn.imagesLoaded = function( options, callback ) {
    var instance = new ImagesLoaded( this, options, callback );
    return instance.jqDeferred.promise( $(this) );
  };
};
// try making plugin
ImagesLoaded.makeJQueryPlugin();

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

return ImagesLoaded;

});
