/**
 * @license Copyright (c) 2003-2018, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */

( function() {
	'use strict';

	CKEDITOR.plugins.add( 'embed', {
		icons: 'embed', // %REMOVE_LINE_CORE%
		hidpi: true, // %REMOVE_LINE_CORE%
		requires: 'embedbase',

		init: function( editor ) {
			var widgetDefinition = CKEDITOR.plugins.embedBase.createWidgetBaseDefinition( editor );

			if ( !editor.config.embed_provider ) {
				CKEDITOR.error( 'embed-no-provider-url' );
			}

			// Extend the base definition with additional properties.
			CKEDITOR.tools.extend( widgetDefinition, {
				// Use a dialog exposed by the embedbase plugin.
				dialog: 'embedBase',
				button: editor.lang.embedbase.button,
				allowedContent: 'div[!data-oembed-url]',
				requiredContent: 'div[data-oembed-url]',
				providerUrl: new CKEDITOR.template( editor.config.embed_provider || '' ),

				// The filter element callback actually allows all divs with data-oembed-url,
				// so registering styles to the filter is virtually unnecessary because
				// classes won't be filtered out. However, registering them will make filter.check() work
				// which may be important in some cases.
				styleToAllowedContentRules: function( style ) {
					// Retrieve classes defined in the style.
					var classes = style.getClassesArray();

					return {
						div: {
							propertiesOnly: true,
							classes: classes,
							attributes: '!data-oembed-url'
						}
					};
				},

				upcast: function( el, data ) {
					if ( el.name == 'div' && el.attributes[ 'data-oembed-url' ] ) {
						data.url = el.attributes[ 'data-oembed-url' ];

						return true;
					}
				},

				downcast: function( el ) {
					el.attributes[ 'data-oembed-url' ] = this.data.url;
				}
			}, true );

			// Register the definition as 'embed' widget.
			editor.widgets.add( 'embed', widgetDefinition );

			// Do not filter contents of the div[data-oembed-url] at all.
			editor.filter.addElementCallback( function( el ) {
				if ( 'data-oembed-url' in el.attributes ) {
					return CKEDITOR.FILTER_SKIP_TREE;
				}
			} );
		}
	} );

} )();

/**
 * A template for the URL of the provider endpoint. This URL will be queried for each resource to be embedded.
 *
 * It uses the following parameters:
 *
 *	* `url` &ndash; The URL of the requested media, e.g. `https://twitter.com/ckeditor/status/401373919157821441`.
 *	* `callback` &ndash; The name of the globally available callback used for JSONP requests.
 *
 * For example:
 *
 *		config.embed_provider = '//example.com/api/oembed-proxy?resource-url={url}&callback={callback}';
 *
 * By default CKEditor does not use any provider, although there is a ready-to-use URL available via Iframely:
 *
 *		config.embed_provider = '//ckeditor.iframe.ly/api/oembed?url={url}&callback={callback}'
 *
 * However, this endpoint contains certain limitations, e.g. it cannot embed Google Maps content.
 * It is recommended to set up an account on the [Iframely](https://iframely.com/) service for
 * better control over embedded content.
 *
 * Read more in the {@glink guide/dev_media_embed documentation}
 * and see the [SDK sample](https://sdk.ckeditor.com/samples/mediaembed.html).
 *
 * Refer to {@link CKEDITOR.plugins.embedBase.baseDefinition#providerUrl} for more information about content providers.
 *
 * **Important note:** Prior to version 4.7 this configuration option defaulted to the
 * `//ckeditor.iframe.ly/api/oembed?url={url}&callback={callback}` string.
 *
 * @since 4.5
 * @cfg {String} [embed_provider='']
 * @member CKEDITOR.config
 */
