/**

 * WordPress inline HTML embed

 *

 * @since 4.4.0

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

 *

 * Single line comments should not be used since they will break

 * the script when inlined in get_post_embed_html(), specifically

 * when the comments are not stripped out due to SCRIPT_DEBUG

 * being turned on.

 */

(function ( window, document ) {

	'use strict';

	/* Abort for ancient browsers. */

	if ( ! document.querySelector || ! window.addEventListener || typeof URL === 'undefined' ) {

		return;

	}

	/** @namespace wp */

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

	/* Abort if script was already executed. */

	if ( !! window.wp.receiveEmbedMessage ) {

		return;

	}

	/**

	 * Receive embed message.

	 *

	 * @param {MessageEvent} e

	 */

	window.wp.receiveEmbedMessage = function( e ) {

		var data = e.data;

		/* Verify shape of message. */

		if (

			! ( data || data.secret || data.message || data.value ) ||

			/[^a-zA-Z0-9]/.test( data.secret )

		) {

			return;

		}

		var iframes = document.querySelectorAll( 'iframe[data-secret="' + data.secret + '"]' ),

			blockquotes = document.querySelectorAll( 'blockquote[data-secret="' + data.secret + '"]' ),

			allowedProtocols = new RegExp( '^https?:$', 'i' ),

			i, source, height, sourceURL, targetURL;

		for ( i = 0; i < blockquotes.length; i++ ) {

			blockquotes[ i ].style.display = 'none';

		}

		for ( i = 0; i < iframes.length; i++ ) {

			source = iframes[ i ];

			if ( e.source !== source.contentWindow ) {

				continue;

			}

			source.removeAttribute( 'style' );

			if ( 'height' === data.message ) {

				/* Resize the iframe on request. */

				height = parseInt( data.value, 10 );

				if ( height > 1000 ) {

					height = 1000;

				} else if ( ~~height < 200 ) {

					height = 200;

				}

				source.height = height;

			} else if ( 'link' === data.message ) {

				/* Link to a specific URL on request. */

				sourceURL = new URL( source.getAttribute( 'src' ) );

				targetURL = new URL( data.value );

				if (

					allowedProtocols.test( targetURL.protocol ) &&

					targetURL.host === sourceURL.host &&

					document.activeElement === source

				) {

					window.top.location.href = data.value;

				}

			}

		}

	};

	function onLoad() {

		var iframes = document.querySelectorAll( 'iframe.wp-embedded-content' ),

			i, source, secret;

		for ( i = 0; i < iframes.length; i++ ) {

			/** @var {IframeElement} */

			source = iframes[ i ];

			secret = source.getAttribute( 'data-secret' );

			if ( ! secret ) {

				/* Add secret to iframe */

				secret = Math.random().toString( 36 ).substring( 2, 12 );

				source.src += '#?secret=' + secret;

				source.setAttribute( 'data-secret', secret );

			}

			/*

			 * Let post embed window know that the parent is ready for receiving the height message, in case the iframe

			 * loaded before wp-embed.js was loaded. When the ready message is received by the post embed window, the

			 * window will then (re-)send the height message right away.

			 */

			source.contentWindow.postMessage( {

				message: 'ready',

				secret: secret

			}, '*' );

		}

	}

	window.addEventListener( 'message', window.wp.receiveEmbedMessage, false );

	document.addEventListener( 'DOMContentLoaded', onLoad, false );

})( window, document );