/**

 * Thin jQuery.ajax wrapper for WP REST API requests.

 *

 * Currently only applies to requests that do not use the `wp-api.js` Backbone

 * client library, though this may change.  Serves several purposes:

 *

 * - Allows overriding these requests as needed by customized WP installations.

 * - Sends the REST API nonce as a request header.

 * - Allows specifying only an endpoint namespace/path instead of a full URL.

 *

 * @output wp-includes/js/api-request.js

 */

( function( $ ) {

	var wpApiSettings = window.wpApiSettings;

	function apiRequest( options ) {

		options = apiRequest.buildAjaxOptions( options );

		return apiRequest.transport( options );

	}

	apiRequest.buildAjaxOptions = function( options ) {

		var url = options.url;

		var path = options.path;

		var namespaceTrimmed, endpointTrimmed, apiRoot;

		var headers, addNonceHeader, headerName;

		if (

			typeof options.namespace === 'string' &&

			typeof options.endpoint === 'string'

		) {

			namespaceTrimmed = options.namespace.replace( /^\/|\/$/g, '' );

			endpointTrimmed = options.endpoint.replace( /^\//, '' );

			if ( endpointTrimmed ) {

				path = namespaceTrimmed + '/' + endpointTrimmed;

			} else {

				path = namespaceTrimmed;

			}

		}

		if ( typeof path === 'string' ) {

			apiRoot = wpApiSettings.root;

			path = path.replace( /^\//, '' );

			if ( 'string' === typeof apiRoot && -1 !== apiRoot.indexOf( '?' ) ) {

				path = path.replace( '?', '&' );

			}

			url = apiRoot + path;

		}

		// If ?_wpnonce=... is present, no need to add a nonce header.

		addNonceHeader = ! ( options.data && options.data._wpnonce );

		headers = options.headers || {};

		// If an 'X-WP-Nonce' header (or any case-insensitive variation

		// thereof) was specified, no need to add a nonce header.

		if ( addNonceHeader ) {

			for ( headerName in headers ) {

				if ( headers.hasOwnProperty( headerName ) ) {

					if ( headerName.toLowerCase() === 'x-wp-nonce' ) {

						addNonceHeader = false;

						break;

					}

				}

			}

		}

		if ( addNonceHeader ) {

			// Do not mutate the original headers object, if any.

			headers = $.extend( {

				'X-WP-Nonce': wpApiSettings.nonce

			}, headers );

		}

		// Do not mutate the original options object.

		options = $.extend( {}, options, {

			headers: headers,

			url: url

		} );

		delete options.path;

		delete options.namespace;

		delete options.endpoint;

		return options;

	};

	apiRequest.transport = $.ajax;

	/** @namespace wp */

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

	window.wp.apiRequest = apiRequest;

} )( jQuery );