/**

 * 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.

 *

 * @since 4.9.0

 * @since 5.6.0 Added overriding of the "PUT" and "DELETE" methods with "POST".

 *              Added an "application/json" Accept header to all requests.

 * @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 method = options.method;

		var namespaceTrimmed, endpointTrimmed, apiRoot;

		var headers, addNonceHeader, addAcceptHeader, 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( /^\//, '' );

			// API root may already include query parameter prefix

			// if site is configured to use plain permalinks.

			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 );

		addAcceptHeader = true;

		headers = options.headers || {};

		for ( headerName in headers ) {

			if ( ! headers.hasOwnProperty( headerName ) ) {

				continue;

			}

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

			// thereof) was specified, no need to add the header again.

			switch ( headerName.toLowerCase() ) {

				case 'x-wp-nonce':

					addNonceHeader = false;

					break;

				case 'accept':

					addAcceptHeader = false;

					break;

			}

		}

		if ( addNonceHeader ) {

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

			headers = $.extend( {

				'X-WP-Nonce': wpApiSettings.nonce

			}, headers );

		}

		if ( addAcceptHeader ) {

			headers = $.extend( {

				'Accept': 'application/json, */*;q=0.1'

			}, headers );

		}

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

			method = method.toUpperCase();

			if ( 'PUT' === method || 'DELETE' === method ) {

				headers = $.extend( {

					'X-HTTP-Method-Override': method

				}, headers );

				method = 'POST';

			}

		}

		// Do not mutate the original options object.

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

			headers: headers,

			url: url,

			method: method

		} );

		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 );