import { ComponentPublicInstance } from 'vue'
import { extend } from '@vue/shared'
import { normalizeTarget } from '@dcloudio/uni-shared'
import { getWindowOffset } from '../../helpers'

const isClickEvent = (val: Event): val is MouseEvent => val.type === 'click'
const isMouseEvent = (val: Event): val is MouseEvent =>
  val.type.indexOf('mouse') === 0
// normalizeNativeEvent
export function $nne(this: ComponentPublicInstance, evt: Event) {
  // 目前内置组件底层实现，当需要访问原始event时，请使用withWebEvent包裹
  // 用法参考：uni-h5/src/framework/components/page/page-refresh/index.ts
  const { currentTarget } = evt
  if (!(evt instanceof Event) || !(currentTarget instanceof HTMLElement)) {
    return evt
  }
  if (currentTarget.tagName.indexOf('UNI-') !== 0) {
    return evt
  }

  const res = createNativeEvent(evt)

  if (isClickEvent(evt)) {
    normalizeClickEvent(res as unknown as WechatMiniprogram.Touch, evt)
  } else if (__PLATFORM__ === 'h5' && isMouseEvent(evt)) {
    normalizeMouseEvent(res as unknown as WechatMiniprogram.Touch, evt)
  } else if (evt instanceof TouchEvent) {
    const { top } = getWindowOffset()
    ;(res as any).touches = normalizeTouchEvent(evt.touches, top)
    ;(res as any).changedTouches = normalizeTouchEvent(evt.changedTouches, top)
  }

  return res
}

export function createNativeEvent(evt: Event | TouchEvent) {
  const { type, timeStamp, target, currentTarget } = evt
  const event = {
    type,
    timeStamp,
    target: normalizeTarget(target as HTMLElement),
    detail: {},
    currentTarget: normalizeTarget(currentTarget as HTMLElement),
  }
  if (evt.type.startsWith('touch')) {
    ;(event as any).touches = (evt as TouchEvent).touches
    ;(event as any).changedTouches = (evt as TouchEvent).changedTouches
  }
  if (__PLATFORM__ === 'h5') {
    extend(event, {
      preventDefault() {
        return evt.preventDefault()
      },
      stopPropagation() {
        return evt.stopPropagation()
      },
    })
  }
  return event
}

function normalizeClickEvent(
  evt: WechatMiniprogram.Touch,
  mouseEvt: MouseEvent
) {
  const { x, y } = mouseEvt
  const { top } = getWindowOffset()
  evt.detail = { x, y: y - top }
  evt.touches = evt.changedTouches = [createTouchEvent(mouseEvt)]
}

function normalizeMouseEvent(evt: Record<string, any>, mouseEvt: MouseEvent) {
  const { top } = getWindowOffset()
  evt.pageX = mouseEvt.pageX
  evt.pageY = mouseEvt.pageY - top
  evt.clientX = mouseEvt.clientX
  evt.clientY = mouseEvt.clientY - top
}

function createTouchEvent(evt: MouseEvent) {
  return {
    force: 1,
    identifier: 0,
    clientX: evt.clientX,
    clientY: evt.clientY,
    pageX: evt.pageX,
    pageY: evt.pageY,
  }
}

function normalizeTouchEvent(touches: TouchList, top: number) {
  const res = []
  for (let i = 0; i < touches.length; i++) {
    const { identifier, pageX, pageY, clientX, clientY, force } = touches[i]
    res.push({
      identifier,
      pageX,
      pageY: pageY - top,
      clientX: clientX,
      clientY: clientY - top,
      force: force || 0,
    })
  }
  return res
}