tjy-uniapp/src/components/SpreadDesigner/tools/spreadUtils.ts

/**
 * 纯工具函数 —— 类型判断、数据转换、日期解析
 * 无组件状态依赖、无副作用（除类型转换的 console.error）
 */

export function is(val, type) {
  return Object.prototype.toString.call(val) === `[object ${type}]`
}

export function changeStringToObject(json) {
  if (is(json, 'String') && json?.length) {
    return changeStringToObject(JSON.parse(json))
  } else if (is(json, 'Object')) {
    return json
  } else {
    console.error('数据类型不正确!')
    return null
  }
}

export function base64ToBlob(base64Data, contentType = '') {
  const byteCharacters = atob(base64Data)
  const byteNumbers = new Array(byteCharacters.length)
  for (let i = 0; i < byteCharacters.length; i++) {
    byteNumbers[i] = byteCharacters.charCodeAt(i)
  }
  const byteArray = new Uint8Array(byteNumbers)
  return new Blob([byteArray], { type: contentType })
}

export function blobToBase64(blob) {
  return new Promise((resolve, reject) => {
    const reader = new FileReader()
    reader.onload = () => {
      const base64 = reader.result.split(',')[1]
      resolve(base64)
    }
    reader.onerror = reject
    reader.readAsDataURL(blob)
  })
}

export function formatterOADateNumber(input) {
  const regex = /OADate\(([\d.]+)\)/
  const match = input.match(regex)
  let OADate = null
  if (match && match[1]) {
    OADate = Number(match[1])
    OADate = isNaN(OADate) ? null : parseInt(OADate)
  }
  return OADate !== null ? new Date(Math.round(OADate - 25569) * 86400000) : null
}