define ['angular', 'sprintf', 'file'], (ng, sprintf) ->
  xnat = ng.module 'qiprofile.xnat', ['qiprofile.file']

  xnat.factory 'XNAT', ['File', (File) ->
    # The image store location relative to the web app root.
    # This is a symbolic link to the image store root directory
    # on the server.
    IMAGE_STORE_ROOT = '/data'

    # @param project the project name
    # @returns the image store project directory
    projectLocation = (project) ->
      "#{ IMAGE_STORE_ROOT }/#{ project }/arc001"
      
      # If the image sequence is a scan, then this method
      # returns the image sequence. Otherwise, this method
      # returns the scan from which the image sequence is
      # derived.
      #
      # @returns the image sequence scan
    scanFor = (imageSequence) ->
      if imageSequence._cls is 'Scan'
        imageSequence
      else if imageSequence.scan?
        imageSequence.scan
      else
        throw new TypeError("Cannot infer the #{ imageSequence.title }" +
                            " parent scan")

    # @param image the REST TimeSeries or Volume object
    # @returns the image file path relative to the web app root
    location = (image) ->
      # The image parent is either a scan or registration image
      # sequence.
      resource = image.resource
      imageSequence = image.imageSequence
      scan = scanFor(imageSequence)
      session = imageSequence.session
      subject = session.subject
      collection = subject.collection
      project = subject.project
      # The XNAT project directory.
      projectDir = projectLocation(project)
      # The scan subdirectory.
      scanDir = "SCANS/#{ scan.number }"
      # The zero-padded subject label number suffix, e.g. "003".
      subjectNumberSuffix = sprintf.sprintf("%03d", subject.number)
      # The subject label, e.g. "Breast003".
      subjectLabel = "#{ collection }#{ subjectNumberSuffix }"
      # The zero-padded session label number suffix, e.g. "01".
      sessionNumberSuffix = sprintf.sprintf("%02d", session.number)
      # The XNAT experiment label, e.g. "Breast003_Session02".
      expLabel = "#{ subjectLabel }_Session#{ sessionNumberSuffix }"
      
      # Return the formatted image file path.
      "#{ projectDir }/#{ expLabel }/#{ scanDir }/#{ resource }/#{ image.name }"

    # Loads the image file content.
    #
    # @param image the image object
    # @returns a promise which resolves to the loaded image file
    #   content
    load: (image) ->
      # The image file path.
      path = location(image)
      # Read the file into an ArrayBuffer.
      File.readBinary(path)
  ]