text: /**
   * @license Copyright (c) 2003-2022, CKSource - Frederico Knabben. All rights reserved.
   * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
   */
  
  /**
   * @module language/textpartlanguagecommand
   */
  
  import { Command } from 'ckeditor5/src/core';
  import { stringifyLanguageAttribute } from './utils';
  
  /**
   * The text part language command plugin.
   *
   * @extends module:core/command~Command
   */
  export default class TextPartLanguageCommand extends Command {
  	/**
  	 * If the selection starts in a language attribute, the value is set to
  	 * the value of that language in a format:
  	 *
  	 *		<languageCode>:<textDirection>
  	 *
  	 * * `languageCode` - The language code used for the `lang` attribute in the [ISO 639-1](https://en.wikipedia.org/wiki/ISO_639-1)
  	 *    format.
  	 * * `textDirection` - One of the following values: `rtl` or `ltr`, indicating the reading direction of the language.
  	 *
  	 * See the {@link module:core/editor/editorconfig~LanguageConfig#textPartLanguage text part language configuration}
  	 * for more information about language properties.
  	 *
  	 * It is set to `false` otherwise.
  	 *
  	 * @observable
  	 * @readonly
  	 * @member {Boolean|String} #value
  	 */
  
  	/**
  	 * @inheritDoc
  	 */
  	refresh() {
  		const model = this.editor.model;
  		const doc = model.document;
  
  		this.value = this._getValueFromFirstAllowedNode();
  		this.isEnabled = model.schema.checkAttributeInSelection( doc.selection, 'language' );
  	}
  
  	/**
  	 * Executes the command. Applies the attribute to the selection or removes it from the selection.
  	 *
  	 * If `languageCode` is set to `false` or a `null` value, it will remove attributes. Otherwise, it will set
  	 * the attribute in the `{@link #value value}` format.
  	 *
  	 * The execution result differs, depending on the {@link module:engine/model/document~Document#selection}:
  	 *
  	 * * If the selection is on a range, the command applies the attribute to all nodes in that range
  	 * (if they are allowed to have this attribute by the {@link module:engine/model/schema~Schema schema}).
  	 * * If the selection is collapsed in a non-empty node, the command applies the attribute to the
  	 * {@link module:engine/model/document~Document#selection} itself (note that typed characters copy attributes from the selection).
  	 * * If the selection is collapsed in an empty node, the command applies the attribute to the parent node of the selection (note
  	 * that the selection inherits all attributes from a node if it is in an empty node).
  	 *
  	 * @fires execute
  	 * @param {Object} [options] Command options.
  	 * @param {String|Boolean} [options.languageCode] The language code to be applied to the model.
  	 * @param {String} [options.textDirection] The language text direction.
  	 */
  	execute( { languageCode, textDirection } = {} ) {
  		const model = this.editor.model;
  		const doc = model.document;
  		const selection = doc.selection;
  
  		const value = languageCode ? stringifyLanguageAttribute( languageCode, textDirection ) : false;
  
  		model.change( writer => {
  			if ( selection.isCollapsed ) {
  				if ( value ) {
  					writer.setSelectionAttribute( 'language', value );
  				} else {
  					writer.removeSelectionAttribute( 'language' );
  				}
  			} else {
  				const ranges = model.schema.getValidRanges( selection.getRanges(), 'language' );
  
  				for ( const range of ranges ) {
  					if ( value ) {
  						writer.setAttribute( 'language', value, range );
  					} else {
  						writer.removeAttribute( 'language', range );
  					}
  				}
  			}
  		} );
  	}
  
  	/**
  	 * Returns the attribute value of the first node in the selection that allows the attribute.
  	 * For a collapsed selection it returns the selection attribute.
  	 *
  	 * @private
  	 * @returns {Boolean|String} The attribute value.
  	 */
  	_getValueFromFirstAllowedNode() {
  		const model = this.editor.model;
  		const schema = model.schema;
  		const selection = model.document.selection;
  
  		if ( selection.isCollapsed ) {
  			return selection.getAttribute( 'language' ) || false;
  		}
  
  		for ( const range of selection.getRanges() ) {
  			for ( const item of range.getItems() ) {
  				if ( schema.checkAttribute( item, 'language' ) ) {
  					return item.getAttribute( 'language' ) || false;
  				}
  			}
  		}
  
  		return false;
  	}
  }
  