/**
* @output wp-includes/js/wp-util.js
*/

/* global _wpUtilSettings */

/** @namespace wp */
window.wp = window.wp || {};

(function ($) {
// Check for the utility settings.
var settings = typeof _wpUtilSettings === 'undefined' ? {} : _wpUtilSettings;

/**
* wp.template( id )
*
* Fetch a JavaScript template for an id, and return a templating function for it.
*
* @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.
*/
wp.template = _.memoize(function ( id ) {
var compiled,
/*
* Underscore's default ERB-style templates are incompatible with PHP
* when asp_tags is enabled, so WordPress uses Mustache-inspired templating syntax.
*
* @see trac ticket #22344.
*/
options = {
evaluate: /<#([\s\S]+?)#>/g,
interpolate: /\{\{\{([\s\S]+?)\}\}\}/g,
escape: /\{\{([^\}]+?)\}\}(?!\})/g,
variable: 'data'
};

return function ( data ) {
if ( ! document.getElementById( 'tmpl-' + id ) ) {
throw new Error( 'Template not found: ' + '#tmpl-' + id );
}
compiled = compiled || _.template( $( '#tmpl-' + id ).html(), options );
return compiled( data );
};
});

/*
* wp.ajax
* ------
*
* Tools for sending ajax requests with JSON responses and built in error handling.
* Mirrors and wraps jQuery's ajax APIs.
*/
wp.ajax = {
settings: settings.ajax || {},

/**
* wp.ajax.post( [action], [data] )
*
* Sends a POST request to WordPress.
*
* @param {(string|Object)} action The slug of the action to fire in WordPress or options passed
* to jQuery.ajax.
* @param {Object=} data Optional. The data to populate $_POST with.
* @return {$.promise} A jQuery promise that represents the request,
* decorated with an abort() method.
*/
post: function( action, data ) {
return wp.ajax.send({
data: _.isObject( action ) ? action : _.extend( data || {}, { action: action })
});
},

/**
* wp.ajax.send( [action], [options] )
*
* Sends a POST request to WordPress.
*
* @param {(string|Object)} action The slug of the action to fire in WordPress or options passed
* to jQuery.ajax.
* @param {Object=} options Optional. The options passed to jQuery.ajax.
* @return {$.promise} A jQuery promise that represents the request,
* decorated with an abort() method.
*/
send: function( action, options ) {
var promise, deferred;
if ( _.isObject( action ) ) {
options = action;
} else {
options = options || {};
options.data = _.extend( options.data || {}, { action: action });
}

options = _.defaults( options || {}, {
type: 'POST',
url: wp.ajax.settings.url,
context: this
});

deferred = $.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().
deferred.jqXHR = $.ajax( options ).done( function( response ) {
// Treat a response of 1 as successful for backward compatibility with existing handlers.
if ( response === '1' || response === 1 ) {
response = { success: true };
}

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

// When handling a media attachments request, get the total attachments from response headers.
var context = this;
deferred.done( function() {
if (
action &&
action.data &&
'query-attachments' === action.data.action &&
deferred.jqXHR.hasOwnProperty( 'getResponseHeader' ) &&
deferred.jqXHR.getResponseHeader( 'X-WP-Total' )
) {
context.totalAttachments = parseInt( deferred.jqXHR.getResponseHeader( 'X-WP-Total' ), 10 );
} else {
context.totalAttachments = 0;
}
} );
deferred[ response.success ? 'resolveWith' : 'rejectWith' ]( this, [response.data] );
} else {
deferred.rejectWith( this, [response] );
}
}).fail( function() {
deferred.rejectWith( this, arguments );
});
});

promise = deferred.promise();
promise.abort = function() {
deferred.jqXHR.abort();
return this;
};

return promise;
}
};

}(jQuery));