export default function useScrollHeight() {
  const getScrollTop = () => {
    let scrollTop:number = 0,
      bodyScrollTop:number = 0,
      documentScrollTop:number = 0
    if (document.body) {
      bodyScrollTop = document.body.scrollTop
    }
    if (document.documentElement) {
      documentScrollTop = document.documentElement.scrollTop
    }
    scrollTop = bodyScrollTop - documentScrollTop > 0 ? bodyScrollTop : documentScrollTop
    return scrollTop
  }
  //浏览器视口滚动的高度
  const getScrollHeight = () => {
    let scrollHeight:number = 0,
      bodyScrollHeight:number = 0,
      documentScrollHeight:number = 0
    if (document.body) {
      bodyScrollHeight = document.body.scrollHeight
    }
    if (document.documentElement) {
      documentScrollHeight = document.documentElement.scrollHeight
    }
    scrollHeight = bodyScrollHeight - documentScrollHeight > 0 ? bodyScrollHeight : documentScrollHeight
    return scrollHeight
  }
  //浏览器视口的高度
  const getWindowHeight = () => {
    let windowHeight:number = 0
    if (document.compatMode == 'CSS1Compat') {
      windowHeight = document.documentElement.clientHeight
    } else {
      windowHeight = document.body.clientHeight
    }
    return windowHeight
  }
  return {
    getScrollTop,
    getScrollHeight,
    getWindowHeight,
  }
}