/* eslint-disable no-underscore-dangle */
let _IS_MAC = false
let _IS_IOS = false
let _IS_WINDOWS = false
let _IS_IE = false
let _IS_IE11 = false
let _IS_EDGE = false
let _IS_NETSCAPE = false
let _IS_CHROME_APP = false
let _IS_CHROME = false
let _IS_OPERA = false
let _IS_FIREFOX = false
let _IS_SAFARI = false
let _SUPPORT_TOUCH = false
let _SUPPORT_POINTER = false
let _SUPPORT_PASSIVE = false
let _NO_FOREIGNOBJECT = false

if (typeof navigator === 'object') {
  const ua = navigator.userAgent
  _IS_MAC = ua.indexOf('Macintosh') >= 0
  _IS_IOS = !!ua.match(/(iPad|iPhone|iPod)/g)
  _IS_WINDOWS = ua.indexOf('Windows') >= 0

  _IS_IE = ua.indexOf('MSIE') >= 0
  _IS_IE11 = !!ua.match(/Trident\/7\./)
  _IS_EDGE = !!ua.match(/Edge\//)

  _IS_NETSCAPE =
    ua.indexOf('Mozilla/') >= 0 &&
    ua.indexOf('MSIE') < 0 &&
    ua.indexOf('Edge/') < 0

  _IS_CHROME = ua.indexOf('Chrome/') >= 0 && ua.indexOf('Edge/') < 0
  _IS_OPERA = ua.indexOf('Opera/') >= 0 || ua.indexOf('OPR/') >= 0
  _IS_FIREFOX = ua.indexOf('Firefox/') >= 0
  _IS_SAFARI =
    ua.indexOf('AppleWebKit/') >= 0 &&
    ua.indexOf('Chrome/') < 0 &&
    ua.indexOf('Edge/') < 0

  if (typeof document === 'object') {
    _NO_FOREIGNOBJECT =
      !document.createElementNS ||
      `${document.createElementNS(
        'http://www.w3.org/2000/svg',
        'foreignObject',
      )}` !== '[object SVGForeignObjectElement]' ||
      ua.indexOf('Opera/') >= 0
  }
}

if (typeof window === 'object') {
  _IS_CHROME_APP =
    (window as any).chrome != null &&
    (window as any).chrome.app != null &&
    (window as any).chrome.app.runtime != null
  _SUPPORT_POINTER = (window as any).PointerEvent != null && !_IS_MAC
}

if (typeof document === 'object') {
  _SUPPORT_TOUCH = 'ontouchstart' in document.documentElement

  try {
    const options = Object.defineProperty({}, 'passive', {
      get() {
        _SUPPORT_PASSIVE = true
      },
    })
    const div = document.createElement('div')
    if (div.addEventListener) {
      div.addEventListener('click', () => {}, options)
    }
  } catch (err) {
    // pass
  }
}
export const IS_MAC = _IS_MAC
export const IS_IOS = _IS_IOS
export const IS_WINDOWS = _IS_WINDOWS

export const IS_IE = _IS_IE
export const IS_IE11 = _IS_IE11
export const IS_EDGE = _IS_EDGE

/**
 * A flag indicating whether the browser is Netscape (including Firefox).
 */
export const IS_NETSCAPE = _IS_NETSCAPE

/**
 * A flag indicating whether the the this is running inside a Chrome App.
 */
export const IS_CHROME_APP = _IS_CHROME_APP

export const IS_CHROME = _IS_CHROME
export const IS_OPERA = _IS_OPERA
export const IS_FIREFOX = _IS_FIREFOX
export const IS_SAFARI = _IS_SAFARI

/**
 * A flag indicating whether this device supports touchstart/-move/-end
 * events (Apple iOS, Android, Chromebook and Chrome Browser on touch-enabled
 * devices).
 */
export const SUPPORT_TOUCH = _SUPPORT_TOUCH

/**
 * A flag indicating whether this device supports Microsoft pointer events.
 */
export const SUPPORT_POINTER = _SUPPORT_POINTER

export const SUPPORT_PASSIVE = _SUPPORT_PASSIVE

/**
 * A flag indicating whether foreignObject support is not available. This
 * is the case for Opera, older SVG-based browsers and all versions of IE.
 */
export const NO_FOREIGNOBJECT = _NO_FOREIGNOBJECT

export const SUPPORT_FOREIGNOBJECT = !NO_FOREIGNOBJECT

export function getHMRStatus() {
  const mod = window.module as any
  if (mod != null && mod.hot != null && mod.hot.status != null) {
    return mod.hot.status()
  }
  return 'unkonwn'
}

export function isApplyingHMR() {
  return getHMRStatus() === 'apply'
}

// This function checks if the specified event is supported by the browser.
// Source: http://perfectionkills.com/detecting-event-support-without-browser-sniffing/
const TAGNAMES: { [event: string]: string } = {
  select: 'input',
  change: 'input',
  submit: 'form',
  reset: 'form',
  error: 'img',
  load: 'img',
  abort: 'img',
}

export function isEventSupported(event: string) {
  const elem = document.createElement(TAGNAMES[event] || 'div')
  const eventName = `on${event}`
  let isSupported = eventName in elem
  if (!isSupported) {
    elem.setAttribute(eventName, 'return;')
    isSupported = typeof (elem as any)[eventName] === 'function'
  }
  return isSupported
}