/**

 * Heartbeat API

 *

 * Note: this API is "experimental" meaning it will likely change a lot

 * in the next few releases based on feedback from 3.6.0. If you intend

 * to use it, please follow the development closely.

 *

 * Heartbeat is a simple server polling API that sends XHR requests to

 * the server every 15 seconds and triggers events (or callbacks) upon

 * receiving data. Currently these 'ticks' handle transports for post locking,

 * login-expiration warnings, and related tasks while a user is logged in.

 *

 * Available filters in ajax-actions.php:

 * - heartbeat_received

 * - heartbeat_send

 * - heartbeat_tick

 * - heartbeat_nopriv_received

 * - heartbeat_nopriv_send

 * - heartbeat_nopriv_tick

 * @see wp_ajax_nopriv_heartbeat(), wp_ajax_heartbeat()

 *

 * @since 3.6.0

 */

 // Ensure the global `wp` object exists.

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

(function($){

	var Heartbeat = function() {

		var self = this,

			running,

			beat,

			screenId = typeof pagenow != 'undefined' ? pagenow : '',

			url = typeof ajaxurl != 'undefined' ? ajaxurl : '',

			settings,

			tick = 0,

			queue = {},

			interval,

			connecting,

			countdown = 0,

			errorcount = 0,

			tempInterval,

			hasFocus = true,

			isUserActive,

			userActiveEvents,

			winBlurTimeout,

			frameBlurTimeout = -1,

			hasConnectionError = null;

		/**

		 * Returns a boolean that's indicative of whether or not there is a connection error

		 *

		 * @returns boolean

		 */

		this.hasConnectionError = function() {

			return !! hasConnectionError;

		};

		if ( typeof( window.heartbeatSettings ) == 'object' ) {

			settings = $.extend( {}, window.heartbeatSettings );

			// Add private vars

			url = settings.ajaxurl || url;

			delete settings.ajaxurl;

			delete settings.nonce;

			interval = settings.interval || 15; // default interval

			delete settings.interval;

			// The interval can be from 15 to 60 sec. and can be set temporarily to 5 sec.

			if ( interval < 15 )

				interval = 15;

			else if ( interval > 60 )

				interval = 60;

			interval = interval * 1000;

			// 'screenId' can be added from settings on the front-end where the JS global 'pagenow' is not set

			screenId = screenId || settings.screenId || 'front';

			delete settings.screenId;

			// Add or overwrite public vars

			$.extend( this, settings );

		}

		function time(s) {

			if ( s )

				return parseInt( (new Date()).getTime() / 1000 );

			return (new Date()).getTime();

		}

		function isLocalFrame( frame ) {

			var origin, src = frame.src;

			if ( src && /^https?:\/\//.test( src ) ) {

				origin = window.location.origin ? window.location.origin : window.location.protocol + '//' + window.location.host;

				if ( src.indexOf( origin ) !== 0 )

					return false;

			}

			try {

				if ( frame.contentWindow.document )

					return true;

			} catch(e) {}

			return false;

		}

		// Set error state and fire an event on XHR errors or timeout

		function errorstate( error, status ) {

			var trigger;

			if ( error ) {

				switch ( error ) {

					case 'abort':

						// do nothing

						break;

					case 'timeout':

						// no response for 30 sec.

						trigger = true;

						break;

					case 'parsererror':

					case 'error':

					case 'empty':

					case 'unknown':

						errorcount++;

						if ( errorcount > 2 )

							trigger = true;

						break;

				}

				if ( 503 == status && false === hasConnectionError ) {

					trigger = true;

				}

				if ( trigger && ! self.hasConnectionError() ) {

					hasConnectionError = true;

					$(document).trigger( 'heartbeat-connection-lost', [error, status] );

				}

			} else if ( self.hasConnectionError() ) {

				errorcount = 0;

				hasConnectionError = false;

				$(document).trigger( 'heartbeat-connection-restored' );

			} else if ( null === hasConnectionError ) {

				hasConnectionError = false;

			}

		}

		function connect() {

			var send = {}, data, i, empty = true,

			nonce = typeof window.heartbeatSettings == 'object' ? window.heartbeatSettings.nonce : '';

			tick = time();

			data = $.extend( {}, queue );

			// Clear the data queue, anything added after this point will be send on the next tick

			queue = {};

			$(document).trigger( 'heartbeat-send', [data] );

			for ( i in data ) {

				if ( data.hasOwnProperty( i ) ) {

					empty = false;

					break;

				}

			}

			// If nothing to send (nothing is expecting a response),

			// schedule the next tick and bail

			if ( empty && ! self.hasConnectionError() ) {

				connecting = false;

				next();

				return;

			}

			send.data = data;

			send.interval = interval / 1000;

			send._nonce = nonce;

			send.action = 'heartbeat';

			send.screen_id = screenId;

			send.has_focus = hasFocus;

			connecting = true;

			self.xhr = $.ajax({

				url: url,

				type: 'post',

				timeout: 30000, // throw an error if not completed after 30 sec.

				data: send,

				dataType: 'json'

			}).done( function( response, textStatus, jqXHR ) {

				var new_interval;

				if ( ! response )

					return errorstate( 'empty' );

				// Clear error state

				if ( self.hasConnectionError() )

					errorstate();

				if ( response.nonces_expired ) {

					$(document).trigger( 'heartbeat-nonces-expired' );

					return;

				}

				// Change the interval from PHP

				if ( response.heartbeat_interval ) {

					new_interval = response.heartbeat_interval;

					delete response.heartbeat_interval;

				}

				self.tick( response, textStatus, jqXHR );

				// do this last, can trigger the next XHR if connection time > 5 sec. and new_interval == 'fast'

				if ( new_interval )

					self.interval.call( self, new_interval );

			}).always( function() {

				connecting = false;

				next();

			}).fail( function( jqXHR, textStatus, error ) {

				errorstate( textStatus || 'unknown', jqXHR.status );

				self.error( jqXHR, textStatus, error );

			});

		}

		function next() {

			var delta = time() - tick, t = interval;

			if ( ! running )

				return;

			if ( ! hasFocus ) {

				t = 100000; // 100 sec. Post locks expire after 120 sec.

			} else if ( countdown > 0 && tempInterval ) {

				t = tempInterval;

				countdown--;

			}

			window.clearTimeout(beat);

			if ( delta < t ) {

				beat = window.setTimeout(

					function(){

						if ( running )

							connect();

					},

					t - delta

				);

			} else {

				connect();

			}

		}

		function blurred() {

			window.clearTimeout(winBlurTimeout);

			window.clearTimeout(frameBlurTimeout);

			winBlurTimeout = frameBlurTimeout = 0;

			hasFocus = false;

		}

		function focused() {

			window.clearTimeout(winBlurTimeout);

			window.clearTimeout(frameBlurTimeout);

			winBlurTimeout = frameBlurTimeout = 0;

			isUserActive = time();

			if ( hasFocus )

				return;

			hasFocus = true;

			window.clearTimeout(beat);

			if ( ! connecting )

				next();

		}

		function setFrameEvents() {

			$('iframe').each( function( i, frame ){

				if ( ! isLocalFrame( frame ) )

					return;

				if ( $.data( frame, 'wp-heartbeat-focus' ) )

					return;

				$.data( frame, 'wp-heartbeat-focus', 1 );

				$( frame.contentWindow ).on( 'focus.wp-heartbeat-focus', function(e) {

					focused();

				}).on('blur.wp-heartbeat-focus', function(e) {

					setFrameEvents();

					frameBlurTimeout = window.setTimeout( function(){ blurred(); }, 500 );

				});

			});

		}

		$(window).on( 'blur.wp-heartbeat-focus', function(e) {

			setFrameEvents();

			winBlurTimeout = window.setTimeout( function(){ blurred(); }, 500 );

		}).on( 'focus.wp-heartbeat-focus', function() {

			$('iframe').each( function( i, frame ) {

				if ( !isLocalFrame( frame ) )

					return;

				$.removeData( frame, 'wp-heartbeat-focus' );

				$( frame.contentWindow ).off( '.wp-heartbeat-focus' );

			});

			focused();

		});

		function userIsActive() {

			userActiveEvents = false;

			$(document).off( '.wp-heartbeat-active' );

			$('iframe').each( function( i, frame ) {

				if ( ! isLocalFrame( frame ) )

					return;

				$( frame.contentWindow ).off( '.wp-heartbeat-active' );

			});

			focused();

		}

		// Set 'hasFocus = true' if user is active and the window is in the background.

		// Set 'hasFocus = false' if the user has been inactive (no mouse or keyboard activity) for 5 min. even when the window has focus.

		function checkUserActive() {

			var lastActive = isUserActive ? time() - isUserActive : 0;

			// Throttle down when no mouse or keyboard activity for 5 min

			if ( lastActive > 300000 && hasFocus )

				 blurred();

			if ( ! userActiveEvents ) {

				$(document).on( 'mouseover.wp-heartbeat-active keyup.wp-heartbeat-active', function(){ userIsActive(); } );

				$('iframe').each( function( i, frame ) {

					if ( ! isLocalFrame( frame ) )

						return;

					$( frame.contentWindow ).on( 'mouseover.wp-heartbeat-active keyup.wp-heartbeat-active', function(){ userIsActive(); } );

				});

				userActiveEvents = true;

			}

		}

		// Check for user activity every 30 seconds.

		window.setInterval( function(){ checkUserActive(); }, 30000 );

		$(document).ready( function() {

			// Start one tick (15 sec) after DOM ready

			running = true;

			tick = time();

			next();

		});

		this.hasFocus = function() {

			return hasFocus;

		};

		/**

		 * Get/Set the interval

		 *

		 * When setting to 'fast', the interval is 5 sec. for the next 30 ticks (for 2 min and 30 sec).

		 * If the window doesn't have focus, the interval slows down to 2 min.

		 *

		 * @param string speed Interval speed: 'fast' (5sec), 'standard' (15sec) default, 'slow' (60sec)

		 * @param string ticks Used with speed = 'fast', how many ticks before the speed reverts back

		 * @return int Current interval in seconds

		 */

		this.interval = function( speed, ticks ) {

			var reset, seconds;

			ticks = parseInt( ticks, 10 ) || 30;

			ticks = ticks < 1 || ticks > 30 ? 30 : ticks;