/**
 * Copyright (c) 2022 - present TinyVue Authors.
 * Copyright (c) 2022 - present Huawei Cloud Computing Technologies Co., Ltd.
 *
 * Use of this source code is governed by an MIT-style license.
 *
 * THE OPEN SOURCE SOFTWARE IN THIS PRODUCT IS DISTRIBUTED IN THE HOPE THAT IT WILL BE USEFUL,
 * BUT WITHOUT ANY WARRANTY, WITHOUT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR
 * A PARTICULAR PURPOSE. SEE THE APPLICABLE LICENSES FOR MORE DETAILS.
 *
 */

export default (container, selected) => {
  if (!selected) {
    container.scrollTop = 0
    return
  }

  const offsetParents = []
  let pointer = selected.offsetParent

  while (pointer && container !== pointer && container.contains(pointer)) {
    offsetParents.push(pointer)
    pointer = pointer.offsetParent
  }

  const top = selected.offsetTop + offsetParents.reduce((prev, curr) => prev + curr.offsetTop, 0)
  const bottom = top + selected.offsetHeight
  const viewRectTop = container.scrollTop
  const viewRectBottom = viewRectTop + container.clientHeight

  if (top < viewRectTop) {
    container.scrollTop = top
  } else if (bottom > viewRectBottom) {
    container.scrollTop = bottom - container.clientHeight
  }
}
