if ( typeof wp === 'undefined' )

	var wp = {};

(function( exports, $ ) {

	var Uploader;

	if ( typeof _wpPluploadSettings === 'undefined' )

		return;

	/*

	 * An object that helps create a WordPress uploader using plupload.

	 *

	 * @param options - object - The options passed to the new plupload instance.

	 *    Requires the following parameters:

	 *    - container - The id of uploader container.

	 *    - browser   - The id of button to trigger the file select.

	 *    - dropzone  - The id of file drop target.

	 *    - plupload  - An object of parameters to pass to the plupload instance.

	 *    - params    - An object of parameters to pass to $_POST when uploading the file.

	 *                  Extends this.plupload.multipart_params under the hood.

	 *

	 * @param attributes - object - Attributes and methods for this specific instance.

	 */

	Uploader = function( options ) {

		var self = this,

			elements = {

				container: 'container',

				browser:   'browse_button',

				dropzone:  'drop_element'

			},

			key;

		this.supports = {

			upload: Uploader.browser.supported

		};

		this.supported = this.supports.upload;

		if ( ! this.supported )

			return;

		// Use deep extend to ensure that multipart_params and other objects are cloned.

		this.plupload = $.extend( true, { multipart_params: {} }, Uploader.defaults );

		this.container = document.body; // Set default container.

		// Extend the instance with options

		//

		// Use deep extend to allow options.plupload to override individual

		// default plupload keys.

		$.extend( true, this, options );

		// Proxy all methods so this always refers to the current instance.

		for ( key in this ) {

			if ( $.isFunction( this[ key ] ) )

				this[ key ] = $.proxy( this[ key ], this );

		}

		// Ensure all elements are jQuery elements and have id attributes

		// Then set the proper plupload arguments to the ids.

		for ( key in elements ) {

			if ( ! this[ key ] )

				continue;

			this[ key ] = $( this[ key ] ).first();

			if ( ! this[ key ].length ) {

				delete this[ key ];

				continue;

			}

			if ( ! this[ key ].prop('id') )

				this[ key ].prop( 'id', '__wp-uploader-id-' + Uploader.uuid++ );

			this.plupload[ elements[ key ] ] = this[ key ].prop('id');

		}

		// If the uploader has neither a browse button nor a dropzone, bail.

		if ( ! ( this.browser && this.browser.length ) && ! ( this.dropzone && this.dropzone.length ) )

			return;

		this.uploader = new plupload.Uploader( this.plupload );

		delete this.plupload;

		// Set default params and remove this.params alias.

		this.param( this.params || {} );

		delete this.params;

		this.uploader.init();

		this.supports.dragdrop = this.uploader.features.dragdrop && ! Uploader.browser.mobile;

		// Generate drag/drop helper classes.

		(function( dropzone, supported ) {

			var sensitivity = 50,

				active;

			if ( ! dropzone )

				return;

			dropzone.toggleClass( 'supports-drag-drop', !! supported );

			if ( ! supported )

				return dropzone.unbind('.wp-uploader');

			// 'dragenter' doesn't fire correctly,

			// simulate it with a limited 'dragover'

			dropzone.bind( 'dragover.wp-uploader', function(){

				if ( active )

					return;

				dropzone.addClass('drag-over');

				active = true;

			});

			dropzone.bind('dragleave.wp-uploader, drop.wp-uploader', function(){

				active = false;

				dropzone.removeClass('drag-over');

			});

		}( this.dropzone, this.supports.dragdrop ));

		if ( this.browser ) {

			this.browser.on( 'mouseenter', this.refresh );

		} else {

			this.uploader.disableBrowse( true );

			// If HTML5 mode, hide the auto-created file container.

			$('#' + this.uploader.id + '_html5_container').hide();

		}

		this.uploader.bind( 'UploadProgress', this.progress );

		this.uploader.bind( 'FileUploaded', function( up, file, response ) {

			try {

				response = JSON.parse( response.response );

			} catch ( e ) {

				return self.error( pluploadL10n.default_error, e );

			}

			if ( ! response || ! response.type || ! response.data )

				return self.error( pluploadL10n.default_error );

			if ( 'error' === response.type )

				return self.error( response.data.message, response.data );

			if ( 'success' === response.type )

				return self.success( response.data );

		});

		this.uploader.bind( 'Error', function( up, error ) {

			var message = pluploadL10n.default_error,

				key;

			// Check for plupload errors.

			for ( key in Uploader.errorMap ) {

				if ( error.code === plupload[ key ] ) {

					message = Uploader.errorMap[ key ];

					break;

				}

			}

			self.error( message, error );

			up.refresh();

		});

		this.uploader.bind( 'FilesAdded', function( up, files ) {

			$.each( files, function() {

				self.added( this );

			});

			up.refresh();

			up.start();

		});

		this.init();

	};

	// Adds the 'defaults' and 'browser' properties.

	$.extend( Uploader, _wpPluploadSettings );

	Uploader.uuid = 0;

	Uploader.errorMap = {

		'FAILED':                 pluploadL10n.upload_failed,

		'FILE_EXTENSION_ERROR':   pluploadL10n.invalid_filetype,

		// 'FILE_SIZE_ERROR': '',

		'IMAGE_FORMAT_ERROR':     pluploadL10n.not_an_image,

		'IMAGE_MEMORY_ERROR':     pluploadL10n.image_memory_exceeded,

		'IMAGE_DIMENSIONS_ERROR': pluploadL10n.image_dimensions_exceeded,

		'GENERIC_ERROR':          pluploadL10n.upload_failed,

		'IO_ERROR':               pluploadL10n.io_error,

		'HTTP_ERROR':             pluploadL10n.http_error,

		'SECURITY_ERROR':         pluploadL10n.security_error

	};

	$.extend( Uploader.prototype, {

		/**

		 * Acts as a shortcut to extending the uploader's multipart_params object.

		 *

		 * param( key )

		 *    Returns the value of the key.

		 *

		 * param( key, value )

		 *    Sets the value of a key.

		 *

		 * param( map )

		 *    Sets values for a map of data.

		 */

		param: function( key, value ) {

			if ( arguments.length === 1 && typeof key === 'string' )

				return this.uploader.settings.multipart_params[ key ];

			if ( arguments.length > 1 ) {

				this.uploader.settings.multipart_params[ key ] = value;

			} else {

				$.extend( this.uploader.settings.multipart_params, key );

			}

		},

		init:     function() {},

		error:    function() {},

		success:  function() {},

		added:    function() {},

		progress: function() {},

		complete: function() {},

		refresh:  function() {

			this.uploader.refresh();

		}

	});

	exports.Uploader = Uploader;

})( wp, jQuery );