/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
import * as ts from 'typescript';

/**
 * Return the node that most tightly encompasses the specified `position`.
 * @param node The starting node to start the top-down search.
 * @param position The target position within the `node`.
 */
export function findTightestNode(node: ts.Node, position: number): ts.Node|undefined {
  if (node.getStart() <= position && position < node.getEnd()) {
    return node.forEachChild(c => findTightestNode(c, position)) ?? node;
  }
  return undefined;
}

export function getParentClassDeclaration(startNode: ts.Node): ts.ClassDeclaration|undefined {
  while (startNode) {
    if (ts.isClassDeclaration(startNode)) {
      return startNode;
    }
    startNode = startNode.parent;
  }
  return undefined;
}