import { createApp, Component } from 'vue'

export function mountComponent(Com: Component) {
  // 创建挂载节点
  const root = document.createElement('div')
  document.body.appendChild(root)
  // 创建组件实例
  const app = createApp(Com)
  // 挂载组件
  const instance = app.mount(root)

  return {
    instance,
    unmount: () => {
      app.unmount(root)
      document.body.removeChild(root)
    },
  }
}

// 节流函数
export function throttle(func: Function, time: number, isFirst = false) {
  let lastTime = Date.now()
  return (...args: any[]) => {
    if (isFirst) {
      lastTime = Date.now()
      func(args)
      isFirst = false
      return
    }

    const now = Date.now()
    if (now - lastTime >= time) {
      lastTime = now
      func(args)
    }
  }
}

// 查找节点
export function querySelector(selector: Function | Element | string, defaultSelector?: any) {
  if (typeof selector === 'function') {
    selector = selector()
  }
  if (selector instanceof HTMLElement) {
    return selector
  }
  try {
    const el = document.querySelector<any>(selector)
    if (el === null) {
      throw new Error()
    }
    return el
  } catch (err) {
    if (defaultSelector !== undefined) {
      return defaultSelector
    }
    throw new Error('必须提供有效的下拉刷新DOM节点')
  }
}

// 空函数
export function pop(): void {}

// ready
export function domReady(func: Function) {
  if (document.readyState === 'complete') {
    setTimeout(() => func(), 0)
  } else {
    const handler = () => {
      document.removeEventListener('DOMContentLoaded', handler, false)
      func()
    }
    document.addEventListener('DOMContentLoaded', handler, false)
  }
}