export function getBoundingClientRect(element: Element): DOMRect | number {
  if (!element || !element.getBoundingClientRect) {
    return 0
  }
  return element.getBoundingClientRect()
}

/**
 * Get the left and top offset of the current element
 * left: the distance between the leftmost element and the left side of the document
 * top: the distance from the top of the element to the top of the document
 * right: the distance from the far right of the element to the right of the document
 * bottom: the distance from the bottom of the element to the bottom of the document
 * rightIncludeBody: the distance between the leftmost element and the right side of the document
 * bottomIncludeBody: the distance from the bottom of the element to the bottom of the document
 *
 * @description:
 */
export function getViewportOffset(element: Element): ViewportOffsetResult {
  const doc = document.documentElement

  const docScrollLeft = doc.scrollLeft
  const docScrollTop = doc.scrollTop
  const docClientLeft = doc.clientLeft
  const docClientTop = doc.clientTop

  const { pageXOffset } = window
  const { pageYOffset } = window

  const box = getBoundingClientRect(element)

  const { left: retLeft, top: rectTop, width: rectWidth, height: rectHeight } = box as DOMRect

  const scrollLeft = (pageXOffset || docScrollLeft) - (docClientLeft || 0)
  const scrollTop = (pageYOffset || docScrollTop) - (docClientTop || 0)
  const offsetLeft = retLeft + pageXOffset
  const offsetTop = rectTop + pageYOffset

  const left = offsetLeft - scrollLeft
  const top = offsetTop - scrollTop

  const { clientWidth } = window.document.documentElement
  const { clientHeight } = window.document.documentElement
  return {
    left,
    top,
    right: clientWidth - rectWidth - left,
    bottom: clientHeight - rectHeight - top,
    rightIncludeBody: clientWidth - left,
    bottomIncludeBody: clientHeight - top
  }
}