text: /**
   * @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
   * For licensing, see LICENSE.md.
   */
  
  /**
   * @module link/findlinkrange
   */
  
  import Range from '@ckeditor/ckeditor5-engine/src/model/range';
  import Position from '@ckeditor/ckeditor5-engine/src/model/position';
  
  /**
   * Walks backward and forward from the start position, node by node, as long as they have the same `linkHref` attribute value and return
   * a {@link module:engine/model/range~Range Range} with the found link.
   *
   * @param {module:engine/model/position~Position} position The start position.
   * @param {String} value The `linkHref` attribute value.
   * @returns {module:engine/model/range~Range} The link range.
   */
  export default function findLinkRange( position, value ) {
  	return new Range( _findBound( position, value, true ), _findBound( position, value, false ) );
  }
  
  // Walks forward or backward (depends on the `lookBack` flag), node by node, as long as they have the same `linkHref` attribute value
  // and returns a position just before or after (depends on the `lookBack` flag) the last matched node.
  //
  // @param {module:engine/model/position~Position} position The start position.
  // @param {String} value The `linkHref` attribute value.
  // @param {Boolean} lookBack Whether the walk direction is forward (`false`) or backward (`true`).
  // @returns {module:engine/model/position~Position} The position just before the last matched node.
  function _findBound( position, value, lookBack ) {
  	// Get node before or after position (depends on `lookBack` flag).
  	// When position is inside text node then start searching from text node.
  	let node = position.textNode || ( lookBack ? position.nodeBefore : position.nodeAfter );
  
  	let lastNode = null;
  
  	while ( node && node.getAttribute( 'linkHref' ) == value ) {
  		lastNode = node;
  		node = lookBack ? node.previousSibling : node.nextSibling;
  	}
  
  	return lastNode ? Position.createAt( lastNode, lookBack ? 'before' : 'after' ) : position;
  }
  