ice.fo.utils/FileUtils.js

export function downloadString (text, filename = `${+new Date()}.txt`) {
  const element = document.createElement('a')
  element.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(text))
  element.setAttribute('download', filename)

  element.style.display = 'none'
  document.body.appendChild(element)

  element.click()

  document.body.removeChild(element)
}

export function makeIconForExtension (ext) {
  switch (ext) {
    case 'png':
    case 'jpg':
    case 'jpeg':
      return 'fas fa-file-image'
    case 'pdf':
      return 'far fa-file-pdf'
    case 'mp4':
    case 'mov':
      return 'far fa-file-video'
    default:
      return 'fas fa-folder'
  }
}

export function makeFileInfo (data) {
  if (!data) {
    return {}
  }

  const { fileName = '', fileSize, storePath } = data

  const actualFileSize = fileSize ? fileSize / (1024 * 1024) : 0
  const fileExtension = fileName.split('.').pop()
  const link = storePath && storePath.startsWith('/file') ? storePath : `/file/${storePath}`

  const icon = makeIconForExtension(fileExtension)

  return {
    icon,
    size: `${actualFileSize.toFixed(2)}MB`,
    link,
    name: fileName,
    url: storePath || '',
  }
}

// Doc: https://stackoverflow.com/questions/18299806/how-to-check-file-mime-type-with-javascript-before-upload
export function checkIsImageVideoFile (blob) {
  return new Promise((resolve) => {
    const fileReader = new FileReader()

    fileReader.onloadend = function (e) {
      const arr = (new Uint8Array(e.target.result)).subarray(0, 4)
      let fileHeader = ''
      for (let i = 0; i < arr.length; i++) {
        fileHeader += arr[i].toString(16)
      }

      const validCode = ['89504e47', '47494638', 'ffd8ffe0', 'ffd8ffe1', 'ffd8ffe2', '66747970', '00014', '3026B275']

      const isValiddMime = validCode.includes(fileHeader)

      resolve(isValiddMime)
    }
    fileReader.readAsArrayBuffer(blob)
  })
}

export function readFileAsBase64 (file) {
  return new Promise((resolve) => {
    const reader = new FileReader()

    reader.readAsDataURL(file)

    reader.addEventListener('load', (e) => {
      const base64 = e.target.result

      const result = {
        src: base64,
        size: file.size,
        name: file.name,
      }

      resolve(result)
    })
  })
}

export function isImageFile (file) {
  return (file.type && file.type.includes('image')) || (file.name && file.name.match(/\.(gif|jpe?g|png)$/i))
}

export function extractFileNameFromUrl (url) {
  const splitUrl = /\/([^/]+)\/?$/.exec(url)
  return splitUrl != null ? splitUrl[1] : ''
}

export function generateFileObject (file, serverApi) {
  if (!file || !serverApi) {
    return null
  }
  if (Array.isArray(file)) {
    return file.map(item => generateFileObject(item, serverApi))
  }
  const url = typeof file === 'string' ? file : file.url || file.file || ''
  const pathname = url.substring(serverApi.length)
  const downloadUrl = `${serverApi}/file${pathname}`
  const name = file.name || extractFileNameFromUrl(url)
  return { url, downloadUrl, name, ...file }
}