overleaf/services/web/frontend/js/ide/binary-files/controllers/BinaryFileController.js

import App from '../../../base'

export default App.controller('BinaryFileController', function(
  $scope,
  $rootScope,
  $http,
  $timeout,
  $element,
  ide,
  waitFor
) {
  const MAX_FILE_SIZE = 2 * 1024 * 1024
  const MAX_URL_LENGTH = 60
  const FRONT_OF_URL_LENGTH = 35
  const FILLER = '...'
  const TAIL_OF_URL_LENGTH =
    MAX_URL_LENGTH - FRONT_OF_URL_LENGTH - FILLER.length

  const textExtensions = [
    'tex',
    'latex',
    'sty',
    'cls',
    'bst',
    'bib',
    'bibtex',
    'txt',
    'tikz',
    'rtex',
    'md',
    'asy',
    'latexmkrc',
    'lbx',
    'bbx',
    'cbx',
    'm',
    'lco',
    'dtx',
    'ins',
    'ist',
    'def',
    'clo',
    'ldf',
    'rmd',
    'lua'
  ]
  const imageExtensions = ['png', 'jpg', 'jpeg', 'gif']
  const previewableExtensions = []

  const extension = file =>
    file.name
      .split('.')
      .pop()
      .toLowerCase()

  $scope.isTextFile = () =>
    textExtensions.indexOf(extension($scope.openFile)) > -1
  $scope.isImageFile = () =>
    imageExtensions.indexOf(extension($scope.openFile)) > -1
  $scope.isPreviewableFile = () =>
    previewableExtensions.indexOf(extension($scope.openFile)) > -1
  $scope.isUnpreviewableFile = () =>
    !$scope.isTextFile() && !$scope.isImageFile() && !$scope.isPreviewableFile()

  $scope.textPreview = {
    loading: false,
    shouldShowDots: false,
    error: false,
    data: null
  }

  $scope.refreshing = false
  $scope.refreshError = null

  $scope.displayUrl = function(url) {
    if (url == null) {
      return
    }
    if (url.length > MAX_URL_LENGTH) {
      const front = url.slice(0, FRONT_OF_URL_LENGTH)
      const tail = url.slice(url.length - TAIL_OF_URL_LENGTH)
      return front + FILLER + tail
    }
    return url
  }

  $scope.refreshFile = function(file) {
    $scope.refreshing = true
    $scope.refreshError = null
    ide.fileTreeManager
      .refreshLinkedFile(file)
      .then(function(response) {
        const { data } = response
        const newFileId = data.new_file_id
        $timeout(
          () =>
            waitFor(() => ide.fileTreeManager.findEntityById(newFileId), 5000)
              .then(newFile => ide.binaryFilesManager.openFile(newFile))
              .catch(err => console.warn(err)),

          0
        )
        $scope.refreshError = null
      })
      .catch(response => ($scope.refreshError = response.data))
      .finally(() => {
        $scope.refreshing = false
        const provider = file.linkedFileData.provider
        if (
          provider === 'mendeley' ||
          provider === 'zotero' ||
          file.name.match(/^.*\.bib$/)
        ) {
          ide.$scope.$emit('references:should-reindex', {})
        }
      })
  }

  // Callback fired when the `img` tag fails to load,
  // `failedLoad` used to show the "No Preview" message
  $scope.failedLoad = false
  window.sl_binaryFilePreviewError = () => {
    $scope.failedLoad = true
    $scope.$apply()
  }

  // Callback fired when the `img` tag is done loading,
  // `imgLoaded` is used to show the spinner gif while loading
  $scope.imgLoaded = false
  window.sl_binaryFilePreviewLoaded = () => {
    $scope.imgLoaded = true
    $scope.$apply()
  }

  if ($scope.isTextFile()) {
    loadTextFilePreview()
  }

  function loadTextFilePreview() {
    const url = `/project/${window.project_id}/file/${$scope.openFile.id}`
    let truncated = false
    displayPreviewLoading()
    getFileSize(url)
      .then(fileSize => {
        const opts = {}
        if (fileSize > MAX_FILE_SIZE) {
          truncated = true
          opts.maxSize = MAX_FILE_SIZE
        }
        return getFileContents(url, opts)
      })
      .then(contents => {
        const displayedContents = truncated
          ? truncateFileContents(contents)
          : contents
        displayPreview(displayedContents, truncated)
      })
      .catch(err => {
        console.error(err)
        displayPreviewError()
      })
  }

  function getFileSize(url) {
    return $http.head(url).then(response => {
      const size = parseInt(response.headers('Content-Length'), 10)
      if (isNaN(size)) {
        throw new Error('Could not parse Content-Length header')
      }
      return size
    })
  }

  function getFileContents(url, opts = {}) {
    const { maxSize } = opts
    if (maxSize != null) {
      url += `?range=0-${maxSize}`
    }
    return $http
      .get(url, {
        transformResponse: null // Don't parse JSON
      })
      .then(response => {
        return response.data
      })
  }

  function truncateFileContents(contents) {
    return contents.replace(/\n.*$/, '')
  }

  function displayPreviewLoading() {
    $scope.textPreview.data = null
    $scope.textPreview.loading = true
    $scope.textPreview.shouldShowDots = false
    $scope.$apply()
  }

  function displayPreview(contents, truncated) {
    $scope.textPreview.error = false
    $scope.textPreview.data = contents
    $scope.textPreview.shouldShowDots = truncated
    $timeout(setPreviewHeight, 0)
  }

  function displayPreviewError() {
    $scope.textPreview.error = true
    $scope.textPreview.loading = false
  }

  function setPreviewHeight() {
    const $preview = $element.find('.text-preview .scroll-container')
    const $header = $element.find('.binary-file-header')
    const maxHeight = $element.height() - $header.height() - 14 // borders + margin
    $preview.css({ 'max-height': maxHeight })
    // Don't show the preview until we've set the height, otherwise we jump around
    $scope.textPreview.loading = false
  }
})