export class textFile
{
  /** 保存单文件 text类型的 */
  static saveFile(filename: string, content: string)
  {
    let blob = new Blob([content], { type: 'text/plain;charset=utf-8' })
    this.saveAs(filename, blob)
  }

  /** 读取文件 选择文件组件,读取文档处理函数 */
  static readFile(eleFile, fn_doText, fileType = '', fn_msg = null)
  {
    let noEleFile = !(eleFile)
    if (noEleFile)
    {
      eleFile = document.createElement('input')
      eleFile.type = 'file'
      eleFile.accept = 'text/*'
      eleFile.hidden = true
      document.body.appendChild(eleFile)
    }

    if (fileType && fileType != '')
      eleFile.accept = fileType
    let reader = new FileReader()
    reader.onload = function (event)
    {
      let text = event.target.result
      if (fn_doText)
        fn_doText(text)
    }
    // 选择文件
    eleFile.onchange = function (event)
    {
      let file = event.target.files[0]
      if (file)
      {
        reader.readAsText(file)
      }
      if (fn_msg != null)
      {
        fn_msg()
      }
    }
    eleFile.click()

    if (noEleFile)
    {
      document.body.removeChild(eleFile)
    }
  }

  static getStringFromFile(eleFile, fileType = '', fn_msg = null): string
  {
    let noEleFile = !(eleFile)
    if (noEleFile)
    {
      eleFile = document.createElement('input')
      eleFile.type = 'file'
      eleFile.accept = 'text/*'
      eleFile.hidden = true
      document.body.appendChild(eleFile)
    }

    if (fileType && fileType != '')
      eleFile.accept = fileType
    let reader = new FileReader()
    reader.onload = function (event)
    {
      let text = event.target.result
      return text
    }
    // 选择文件
    eleFile.onchange = function (event)
    {
      let file = event.target.files[0]
      if (file)
      {
        reader.readAsText(file)
      }
      if (fn_msg != null)
      {
        fn_msg()
      }
    }
    eleFile.click()

    if (noEleFile)
    {
      document.body.removeChild(eleFile)
    }
    return ''
  }

  /** 保存文件 */
  static saveAs(fileName: string, data: Blob)
  {
    // 创建隐藏的可下载链接
    let eleLink = document.createElement('a')
    eleLink.download = fileName
    eleLink.style.display = 'none'
    eleLink.href = URL.createObjectURL(data)
    // 触发点击
    document.body.appendChild(eleLink)
    eleLink.click()
    // 然后移除
    document.body.removeChild(eleLink)
  }

  static readFile2()
  {
    let rf = document.createElement('input')
    rf.type = 'file'
    rf.accept = 'text/*'
    rf.hidden = true

    document.body.removeChild(rf)
  }
}