window.wp = window.wp || {};

(function($){

	var Attachment, Attachments, Query, compare, l10n, media;

	/**

	 * wp.media( attributes )

	 *

	 * Handles the default media experience. Automatically creates

	 * and opens a media frame, and returns the result.

	 * Does nothing if the controllers do not exist.

	 *

	 * @param  {object} attributes The properties passed to the main media controller.

	 * @return {object}            A media workflow.

	 */

	media = wp.media = function( attributes ) {

		var MediaFrame = media.view.MediaFrame,

			frame;

		if ( ! MediaFrame )

			return;

		attributes = _.defaults( attributes || {}, {

			frame: 'select'

		});

		if ( 'select' === attributes.frame && MediaFrame.Select )

			frame = new MediaFrame.Select( attributes );

		else if ( 'post' === attributes.frame && MediaFrame.Post )

			frame = new MediaFrame.Post( attributes );

		delete attributes.frame;

		return frame;

	};

	_.extend( media, { model: {}, view: {}, controller: {}, frames: {} });

	// Link any localized strings.

	l10n = media.model.l10n = typeof _wpMediaModelsL10n === 'undefined' ? {} : _wpMediaModelsL10n;

	// Link any settings.

	media.model.settings = l10n.settings || {};

	delete l10n.settings;

	/**

	 * ========================================================================

	 * UTILITIES

	 * ========================================================================

	 */

	/**

	 * A basic comparator.

	 *

	 * @param  {mixed}  a  The primary parameter to compare.

	 * @param  {mixed}  b  The primary parameter to compare.

	 * @param  {string} ac The fallback parameter to compare, a's cid.

	 * @param  {string} bc The fallback parameter to compare, b's cid.

	 * @return {number}    -1: a should come before b.

	 *                      0: a and b are of the same rank.

	 *                      1: b should come before a.

	 */

	compare = function( a, b, ac, bc ) {

		if ( _.isEqual( a, b ) )

			return ac === bc ? 0 : (ac > bc ? -1 : 1);

		else

			return a > b ? -1 : 1;

	};

	_.extend( media, {

		/**

		 * media.template( id )

		 *

		 * Fetches a template by id.

		 *

		 * @param  {string} id   A string that corresponds to a DOM element with an id prefixed with "tmpl-".

		 *                       For example, "attachment" maps to "tmpl-attachment".

		 * @return {function}    A function that lazily-compiles the template requested.

		 */

		template: _.memoize( function( id ) {

			var compiled,

				options = {

					evaluate:    /<#([\s\S]+?)#>/g,

					interpolate: /\{\{\{([\s\S]+?)\}\}\}/g,

					escape:      /\{\{([^\}]+?)\}\}(?!\})/g,

					variable:    'data'

				};

			return function( data ) {

				compiled = compiled || _.template( $( '#tmpl-' + id ).html(), null, options );

				return compiled( data );

			};

		}),

		/**

		 * media.post( [action], [data] )

		 *

		 * Sends a POST request to WordPress.

		 *

		 * @param  {string} action The slug of the action to fire in WordPress.

		 * @param  {object} data   The data to populate $_POST with.

		 * @return {$.promise}     A jQuery promise that represents the request.

		 */

		post: function( action, data ) {

			return media.ajax({

				data: _.isObject( action ) ? action : _.extend( data || {}, { action: action })

			});

		},

		/**

		 * media.ajax( [action], [options] )

		 *

		 * Sends a POST request to WordPress.

		 *

		 * @param  {string} action  The slug of the action to fire in WordPress.

		 * @param  {object} options The options passed to jQuery.ajax.

		 * @return {$.promise}      A jQuery promise that represents the request.

		 */

		ajax: function( action, options ) {

			if ( _.isObject( action ) ) {

				options = action;

			} else {

				options = options || {};

				options.data = _.extend( options.data || {}, { action: action });

			}

			options = _.defaults( options || {}, {

				type:    'POST',

				url:     media.model.settings.ajaxurl,

				context: this

			});

			return $.Deferred( function( deferred ) {

				// Transfer success/error callbacks.

				if ( options.success )

					deferred.done( options.success );

				if ( options.error )

					deferred.fail( options.error );

				delete options.success;

				delete options.error;

				// Use with PHP's wp_send_json_success() and wp_send_json_error()

				$.ajax( options ).done( function( response ) {

					// Treat a response of `1` as successful for backwards

					// compatibility with existing handlers.

					if ( response === '1' || response === 1 )

						response = { success: true };

					if ( _.isObject( response ) && ! _.isUndefined( response.success ) )

						deferred[ response.success ? 'resolveWith' : 'rejectWith' ]( this, [response.data] );

					else

						deferred.rejectWith( this, [response] );

				}).fail( function() {

					deferred.rejectWith( this, arguments );

				});

			}).promise();

		},

		// Scales a set of dimensions to fit within bounding dimensions.

		fit: function( dimensions ) {

			var width     = dimensions.width,

				height    = dimensions.height,

				maxWidth  = dimensions.maxWidth,

				maxHeight = dimensions.maxHeight,

				constraint;

			// Compare ratios between the two values to determine which

			// max to constrain by. If a max value doesn't exist, then the

			// opposite side is the constraint.

			if ( ! _.isUndefined( maxWidth ) && ! _.isUndefined( maxHeight ) ) {

				constraint = ( width / height > maxWidth / maxHeight ) ? 'width' : 'height';

			} else if ( _.isUndefined( maxHeight ) ) {

				constraint = 'width';

			} else if (  _.isUndefined( maxWidth ) && height > maxHeight ) {

				constraint = 'height';

			}

			// If the value of the constrained side is larger than the max,

			// then scale the values. Otherwise return the originals; they fit.

			if ( 'width' === constraint && width > maxWidth ) {

				return {

					width : maxWidth,

					height: Math.round( maxWidth * height / width )

				};

			} else if ( 'height' === constraint && height > maxHeight ) {

				return {

					width : Math.round( maxHeight * width / height ),

					height: maxHeight

				};

			} else {

				return {

					width : width,

					height: height

				};

			}

		},

		// Truncates a string by injecting an ellipsis into the middle.

		// Useful for filenames.

		truncate: function( string, length, replacement ) {

			length = length || 30;

			replacement = replacement || '…';

			if ( string.length <= length )

				return string;

			return string.substr( 0, length / 2 ) + replacement + string.substr( -1 * length / 2 );

		}

	});

	/**

	 * ========================================================================

	 * MODELS

	 * ========================================================================

	 */

	 /**

	  * wp.media.attachment

	  */

	 media.attachment = function( id ) {

		return Attachment.get( id );

	 };

	/**

	 * wp.media.model.Attachment

	 */

	Attachment = media.model.Attachment = Backbone.Model.extend({

		sync: function( method, model, options ) {

			// If the attachment does not yet have an `id`, return an instantly

			// rejected promise. Otherwise, all of our requests will fail.

			if ( _.isUndefined( this.id ) )

				return $.Deferred().rejectWith( this ).promise();

			// Overload the `read` request so Attachment.fetch() functions correctly.

			if ( 'read' === method ) {

				options = options || {};

				options.context = this;

				options.data = _.extend( options.data || {}, {

					action: 'get-attachment',

					id: this.id

				});

				return media.ajax( options );

			// Overload the `update` request so properties can be saved.

			} else if ( 'update' === method ) {

				// If we do not have the necessary nonce, fail immeditately.

				if ( ! this.get('nonces') || ! this.get('nonces').update )

					return $.Deferred().rejectWith( this ).promise();

				options = options || {};

				options.context = this;

				// Set the action and ID.

				options.data = _.extend( options.data || {}, {

					action:  'save-attachment',

					id:      this.id,

					nonce:   this.get('nonces').update,

					post_id: media.model.settings.post.id

				});

				// Record the values of the changed attributes.

				if ( options.changes ) {

					_.each( options.changes, function( value, key ) {

						options.changes[ key ] = this.get( key );

					}, this );

					options.data.changes = options.changes;

					delete options.changes;

				}

				return media.ajax( options );

			// Overload the `delete` request so attachments can be removed.

			// This will permanently delete an attachment.

			} else if ( 'delete' === method ) {

				options = options || {};

				if ( ! options.wait )

					this.destroyed = true;

				options.context = this;

				options.data = _.extend( options.data || {}, {

					action:   'delete-post',

					id:       this.id,

					_wpnonce: this.get('nonces')['delete']

				});

				return media.ajax( options ).done( function() {

					this.destroyed = true;

				}).fail( function() {

					this.destroyed = false;

				});

			}

		},

		parse: function( resp, xhr ) {

			if ( ! resp )

				return resp;

			// Convert date strings into Date objects.

			resp.date = new Date( resp.date );

			resp.modified = new Date( resp.modified );

			return resp;

		},

		saveCompat: function( data, options ) {

			var model = this;

			// If we do not have the necessary nonce, fail immeditately.

			if ( ! this.get('nonces') || ! this.get('nonces').update )

				return $.Deferred().rejectWith( this ).promise();

			return media.post( 'save-attachment-compat', _.defaults({

				id:      this.id,

				nonce:   this.get('nonces').update,

				post_id: media.model.settings.post.id

			}, data ) ).done( function( resp, status, xhr ) {

				model.set( model.parse( resp, xhr ), options );

			});

		}

	}, {

		create: function( attrs ) {

			return Attachments.all.push( attrs );

		},

		get: _.memoize( function( id, attachment ) {

			return Attachments.all.push( attachment || { id: id } );

		})

	});

	/**

	 * wp.media.model.Attachments

	 */

	Attachments = media.model.Attachments = Backbone.Collection.extend({

		model: Attachment,

		initialize: function( models, options ) {

			options = options || {};

			this.props   = new Backbone.Model();

			this.filters = options.filters || {};

			// Bind default `change` events to the `props` model.

			this.props.on( 'change', this._changeFilteredProps, this );

			this.props.on( 'change:order',   this._changeOrder,   this );

			this.props.on( 'change:orderby', this._changeOrderby, this );

			this.props.on( 'change:query',   this._changeQuery,   this );

			// Set the `props` model and fill the default property values.

			this.props.set( _.defaults( options.props || {} ) );

			// Observe another `Attachments` collection if one is provided.

			if ( options.observe )

				this.observe( options.observe );

		},