screen_caster.rb

class Project::ScreenCaster
  attr_reader :project

  PATH_TO_PHANTOM_SCRIPT = Rails.root.join('app','services','project','screen_grab.js')

  def initialize(project)
    @project = project
  end

  def capture
    screen_data
  end

  def update
    project.update screen_data: capture
  end

  def self.capture(project)
    new(project).capture
  end

  private

  def screen_data
    raise StandardError, 'No screen captured' unless phantom_data.present?
    "data:image/png;,#{phantom_data}"
  end

  def phantom_data
    `#{`which node`.strip} #{PATH_TO_PHANTOM_SCRIPT} #{project.url}`.split("\n")[0]
  end
end