/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 - present Instructure, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import { findFocusable } from './findFocusable'
import { UIElement } from '@instructure/shared-types'

/**
 * ---
 * category: utilities/a11y
 * ---
 *
 * Given an element, finds and returns all visible, tabbable children.
 * Tabbable elements include input, select, textarea, button, and object.
 * Anchor tags are also tabbable if they include an href or zero or positive
 * tabindex attribute (to include elements with negative tabindex attributes,
 * use findFocusable).
 *
 * @module findTabbable
 * @param { Node | Window | React.ReactElement | React.Component | function | null } el - component or DOM node
 * @param { boolean } shouldSearchRootNode - should the root node be included in the search
 * @returns { Array } array of all tabbable children
 */
function findTabbable(el?: UIElement, shouldSearchRootNode?: boolean) {
  return findFocusable(
    el,
    (element) => {
      return !isInvalidTabIndex(element.getAttribute('tabindex'))
    },
    shouldSearchRootNode
  )
}

function isInvalidTabIndex(tabIndex: unknown) {
  // TS wants it to be number to be valid, but this method in fact checks if the parameter is a valid positive number
  return !isNaN(tabIndex as any) && (tabIndex as any) < 0
}

export default findTabbable
export { findTabbable }