/* istanbul ignore file */
import * as dom from './dom/index.js'
import { swalClasses } from '../utils/classes.js'

// Fix iOS scrolling http://stackoverflow.com/q/39626302

export const iOSfix = () => {
  const iOS = (/iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream) || (navigator.platform === 'MacIntel' && navigator.maxTouchPoints > 1)
  if (iOS && !dom.hasClass(document.body, swalClasses.iosfix)) {
    const offset = document.body.scrollTop
    document.body.style.top = `${offset * -1}px`
    dom.addClass(document.body, swalClasses.iosfix)
    lockBodyScroll()
    addBottomPaddingForTallPopups() // #1948
  }
}

const addBottomPaddingForTallPopups = () => {
  const safari = !navigator.userAgent.match(/(CriOS|FxiOS|EdgiOS|YaBrowser|UCBrowser)/i)
  if (safari) {
    const bottomPanelHeight = 44
    if (dom.getPopup().scrollHeight > window.innerHeight - bottomPanelHeight) {
      dom.getContainer().style.paddingBottom = `${bottomPanelHeight}px`
    }
  }
}

const lockBodyScroll = () => { // #1246
  const container = dom.getContainer()
  let preventTouchMove
  container.ontouchstart = (e) => {
    preventTouchMove = shouldPreventTouchMove(e)
  }
  container.ontouchmove = (e) => {
    if (preventTouchMove) {
      e.preventDefault()
      e.stopPropagation()
    }
  }
}

const shouldPreventTouchMove = (event) => {
  const target = event.target
  const container = dom.getContainer()
  if (isStylys(event) || isZoom(event)) {
    return false
  }
  if (target === container) {
    return true
  }
  if (
    !dom.isScrollable(container) &&
    target.tagName !== 'INPUT' && // #1603
    target.tagName !== 'TEXTAREA' && // #2266
    !(
      dom.isScrollable(dom.getHtmlContainer()) && // #1944
      dom.getHtmlContainer().contains(target)
    )
  ) {
    return true
  }
  return false
}

const isStylys = (event) => { // #1786
  return event.touches && event.touches.length && event.touches[0].touchType === 'stylus'
}

const isZoom = (event) => { // #1891
  return event.touches && event.touches.length > 1
}

export const undoIOSfix = () => {
  if (dom.hasClass(document.body, swalClasses.iosfix)) {
    const offset = parseInt(document.body.style.top, 10)
    dom.removeClass(document.body, swalClasses.iosfix)
    document.body.style.top = ''
    document.body.scrollTop = (offset * -1)
  }
}
