(function( window, undefined ) {

	'use strict';

	/**

	 * Initialise the WP_API.

	 */

	function WP_API() {

		/** @namespace wp.api.models */

		this.models = {};

		/** @namespace wp.api.collections */

		this.collections = {};

		/** @namespace wp.api.views */

		this.views = {};

	}

	/** @namespace wp */

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

	/** @namespace wp.api */

	wp.api               = wp.api || new WP_API();

	wp.api.versionString = wp.api.versionString || 'wp/v2/';

	// Alias _includes to _.contains, ensuring it is available if lodash is used.

	if ( ! _.isFunction( _.includes ) && _.isFunction( _.contains ) ) {

	  _.includes = _.contains;

	}

})( window );

(function( window, undefined ) {

	'use strict';

	var pad, r;

	/** @namespace wp */

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

	/** @namespace wp.api */

	wp.api = wp.api || {};

	/** @namespace wp.api.utils */

	wp.api.utils = wp.api.utils || {};

	/**

	 * Determine model based on API route.

	 *

	 * @param {string} route    The API route.

	 *

	 * @return {Backbone Model} The model found at given route. Undefined if not found.

	 */

	wp.api.getModelByRoute = function( route ) {

		return _.find( wp.api.models, function( model ) {

			return model.prototype.route && route === model.prototype.route.index;

		} );

	};

	/**

	 * Determine collection based on API route.

	 *

	 * @param {string} route    The API route.

	 *

	 * @return {Backbone Model} The collection found at given route. Undefined if not found.

	 */

	wp.api.getCollectionByRoute = function( route ) {

		return _.find( wp.api.collections, function( collection ) {

			return collection.prototype.route && route === collection.prototype.route.index;

		} );

	};

	/**

	 * ECMAScript 5 shim, adapted from MDN.

	 * @link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString

	 */

	if ( ! Date.prototype.toISOString ) {

		pad = function( number ) {

			r = String( number );

			if ( 1 === r.length ) {

				r = '0' + r;

			}

			return r;

		};

		Date.prototype.toISOString = function() {

			return this.getUTCFullYear() +

				'-' + pad( this.getUTCMonth() + 1 ) +

				'-' + pad( this.getUTCDate() ) +

				'T' + pad( this.getUTCHours() ) +

				':' + pad( this.getUTCMinutes() ) +

				':' + pad( this.getUTCSeconds() ) +

				'.' + String( ( this.getUTCMilliseconds() / 1000 ).toFixed( 3 ) ).slice( 2, 5 ) +

				'Z';

		};

	}

	/**

	 * Parse date into ISO8601 format.

	 *

	 * @param {Date} date.

	 */

	wp.api.utils.parseISO8601 = function( date ) {

		var timestamp, struct, i, k,

			minutesOffset = 0,

			numericKeys = [ 1, 4, 5, 6, 7, 10, 11 ];

		// ES5 §15.9.4.2 states that the string should attempt to be parsed as a Date Time String Format string

		// before falling back to any implementation-specific date parsing, so that’s what we do, even if native

		// implementations could be faster.

		//              1 YYYY                2 MM       3 DD           4 HH    5 mm       6 ss        7 msec        8 Z 9 ±    10 tzHH    11 tzmm

		if ( ( struct = /^(\d{4}|[+\-]\d{6})(?:-(\d{2})(?:-(\d{2}))?)?(?:T(\d{2}):(\d{2})(?::(\d{2})(?:\.(\d{3}))?)?(?:(Z)|([+\-])(\d{2})(?::(\d{2}))?)?)?$/.exec( date ) ) ) {

			// Avoid NaN timestamps caused by “undefined” values being passed to Date.UTC.

			for ( i = 0; ( k = numericKeys[i] ); ++i ) {

				struct[k] = +struct[k] || 0;

			}

			// Allow undefined days and months.

			struct[2] = ( +struct[2] || 1 ) - 1;

			struct[3] = +struct[3] || 1;

			if ( 'Z' !== struct[8]  && undefined !== struct[9] ) {

				minutesOffset = struct[10] * 60 + struct[11];

				if ( '+' === struct[9] ) {

					minutesOffset = 0 - minutesOffset;

				}

			}

			timestamp = Date.UTC( struct[1], struct[2], struct[3], struct[4], struct[5] + minutesOffset, struct[6], struct[7] );

		} else {

			timestamp = Date.parse ? Date.parse( date ) : NaN;

		}

		return timestamp;

	};

	/**

	 * Helper function for getting the root URL.

	 * @return {[type]} [description]

	 */

	wp.api.utils.getRootUrl = function() {

		return window.location.origin ?

			window.location.origin + '/' :

	};

	/**

	 * Helper for capitalizing strings.

	 */

	wp.api.utils.capitalize = function( str ) {

		if ( _.isUndefined( str ) ) {

			return str;

		}

		return str.charAt( 0 ).toUpperCase() + str.slice( 1 );

	};

	/**

	 * Helper function that capitalizes the first word and camel cases any words starting

	 * after dashes, removing the dashes.

	 */

	wp.api.utils.capitalizeAndCamelCaseDashes = function( str ) {

		if ( _.isUndefined( str ) ) {

			return str;

		}

		str = wp.api.utils.capitalize( str );

		return wp.api.utils.camelCaseDashes( str );

	};

	/**

	 * Helper function to camel case the letter after dashes, removing the dashes.

	 */

	wp.api.utils.camelCaseDashes = function( str ) {

		return str.replace( /-([a-z])/g, function( g ) {

			return g[ 1 ].toUpperCase();

		} );

	};

	/**

	 * Extract a route part based on negative index.

	 *

	 * @param {string}   route          The endpoint route.

	 * @param {int}      part           The number of parts from the end of the route to retrieve. Default 1.

	 *                                  Example route `/a/b/c`: part 1 is `c`, part 2 is `b`, part 3 is `a`.

	 * @param {string}  [versionString] Version string, defaults to `wp.api.versionString`.

	 * @param {boolean} [reverse]       Whether to reverse the order when extracting the route part. Optional, default false.

	 */

	wp.api.utils.extractRoutePart = function( route, part, versionString, reverse ) {

		var routeParts;

		part = part || 1;

		versionString = versionString || wp.api.versionString;

		// Remove versions string from route to avoid returning it.

		if ( 0 === route.indexOf( '/' + versionString ) ) {

			route = route.substr( versionString.length + 1 );

		}

		routeParts = route.split( '/' );

		if ( reverse ) {

			routeParts = routeParts.reverse();

		}

		if ( _.isUndefined( routeParts[ --part ] ) ) {

			return '';

		}

		return routeParts[ part ];

	};

	/**

	 * Extract a parent name from a passed route.

	 *

	 * @param {string} route The route to extract a name from.

	 */

	wp.api.utils.extractParentName = function( route ) {

		var name,

			lastSlash = route.lastIndexOf( '_id>[\\d]+)/' );

		if ( lastSlash < 0 ) {

			return '';

		}

		name = route.substr( 0, lastSlash - 1 );

		name = name.split( '/' );

		name.pop();

		name = name.pop();

		return name;

	};

	/**

	 * Add args and options to a model prototype from a route's endpoints.

	 *

	 * @param {array}  routeEndpoints Array of route endpoints.

	 * @param {Object} modelInstance  An instance of the model (or collection)

	 *                                to add the args to.

	 */

	wp.api.utils.decorateFromRoute = function( routeEndpoints, modelInstance ) {

		/**

		 * Build the args based on route endpoint data.

		 */

		_.each( routeEndpoints, function( routeEndpoint ) {

			// Add post and edit endpoints as model args.

			if ( _.includes( routeEndpoint.methods, 'POST' ) || _.includes( routeEndpoint.methods, 'PUT' ) ) {

				// Add any non empty args, merging them into the args object.

				if ( ! _.isEmpty( routeEndpoint.args ) ) {

					// Set as default if no args yet.

					if ( _.isEmpty( modelInstance.prototype.args ) ) {

						modelInstance.prototype.args = routeEndpoint.args;

					} else {

						// We already have args, merge these new args in.

						modelInstance.prototype.args = _.extend( modelInstance.prototype.args, routeEndpoint.args );

					}

				}

			} else {

				// Add GET method as model options.

				if ( _.includes( routeEndpoint.methods, 'GET' ) ) {

					// Add any non empty args, merging them into the defaults object.

					if ( ! _.isEmpty( routeEndpoint.args ) ) {

						// Set as default if no defaults yet.

						if ( _.isEmpty( modelInstance.prototype.options ) ) {

							modelInstance.prototype.options = routeEndpoint.args;

						} else {

							// We already have options, merge these new args in.

							modelInstance.prototype.options = _.extend( modelInstance.prototype.options, routeEndpoint.args );

						}

					}

				}

			}

		} );

	};

	/**

	 * Add mixins and helpers to models depending on their defaults.

	 *

	 * @param {Backbone Model} model          The model to attach helpers and mixins to.

	 * @param {string}         modelClassName The classname of the constructed model.

	 * @param {Object} 	       loadingObjects An object containing the models and collections we are building.

	 */

	wp.api.utils.addMixinsAndHelpers = function( model, modelClassName, loadingObjects ) {

		var hasDate = false,

			/**

			 * Array of parseable dates.

			 *

			 * @type {string[]}.

			 */

			parseableDates = [ 'date', 'modified', 'date_gmt', 'modified_gmt' ],

			/**

			 * Mixin for all content that is time stamped.

			 *

			 * This mixin converts between mysql timestamps and JavaScript Dates when syncing a model

			 * to or from the server. For example, a date stored as `2015-12-27T21:22:24` on the server

			 * gets expanded to `Sun Dec 27 2015 14:22:24 GMT-0700 (MST)` when the model is fetched.

			 *

			 * @type {{toJSON: toJSON, parse: parse}}.

			 */

			TimeStampedMixin = {

				/**

				 * Prepare a JavaScript Date for transmitting to the server.

				 *

				 * This helper function accepts a field and Date object. It converts the passed Date

				 * to an ISO string and sets that on the model field.

				 *

				 * @param {Date}   date   A JavaScript date object. WordPress expects dates in UTC.

				 * @param {string} field  The date field to set. One of 'date', 'date_gmt', 'date_modified'

				 *                        or 'date_modified_gmt'. Optional, defaults to 'date'.

				 */

				setDate: function( date, field ) {

					var theField = field || 'date';

					// Don't alter non parsable date fields.

					if ( _.indexOf( parseableDates, theField ) < 0 ) {

						return false;

					}

					this.set( theField, date.toISOString() );

				},

				/**

				 * Get a JavaScript Date from the passed field.

				 *

				 * WordPress returns 'date' and 'date_modified' in the timezone of the server as well as

				 * UTC dates as 'date_gmt' and 'date_modified_gmt'. Draft posts do not include UTC dates.

				 *

				 * @param {string} field  The date field to set. One of 'date', 'date_gmt', 'date_modified'

				 *                        or 'date_modified_gmt'. Optional, defaults to 'date'.

				 */

				getDate: function( field ) {

					var theField   = field || 'date',

						theISODate = this.get( theField );

					// Only get date fields and non null values.

					if ( _.indexOf( parseableDates, theField ) < 0 || _.isNull( theISODate ) ) {

						return false;

					}

					return new Date( wp.api.utils.parseISO8601( theISODate ) );

				}

			},

			/**

			 * Build a helper function to retrieve related model.

			 *

			 * @param  {string} parentModel      The parent model.

			 * @param  {int}    modelId          The model ID if the object to request

			 * @param  {string} modelName        The model name to use when constructing the model.

			 * @param  {string} embedSourcePoint Where to check the embedds object for _embed data.

			 * @param  {string} embedCheckField  Which model field to check to see if the model has data.

			 *

			 * @return {Deferred.promise}        A promise which resolves to the constructed model.

			 */

			buildModelGetter = function( parentModel, modelId, modelName, embedSourcePoint, embedCheckField ) {

				var getModel, embeddeds, attributes, deferred;

				deferred  = jQuery.Deferred();

				embeddeds = parentModel.get( '_embedded' ) || {};

				// Verify that we have a valid object id.