# Each Node of the repository can have multiple Attachments associated with it.
# This controller is used to handle REST operations for the attachments.
class AttachmentsController < AuthenticatedController
  include ProjectScoped

  before_action :find_or_initialize_node

  # Retrieve all the associated attachments for a given :node_id
  def index
    @attachments = Node.find(params[:node_id]).attachments
    @attachments.each do |a| a.close end
  end

  # Create a new attachment for a given :node_id using a file that has been
  # submitted using an HTML form POST request.
  def create
    uploaded_file = params.fetch(:attachment_file, params.fetch(:files, []).first)

    attachment_name = NamingService.name_file(
      original_filename: uploaded_file.original_filename,
      pathname: Attachment.pwd.join(@node.id.to_s)
    )

    @attachment = Attachment.new(attachment_name, node_id: @node.id)
    @attachment << uploaded_file.read
    @attachment.save

    # new jQuery uploader
    json = {
      name:        @attachment.filename,
      size:        File.size(@attachment.fullpath),
      url:         project_node_attachment_path(current_project, @node, @attachment.filename),
      delete_url:  project_node_attachment_path(current_project, @node, @attachment.filename),
      delete_type: 'DELETE'
    }

    if Mime::Type.lookup_by_extension(File.extname(@attachment.filename).downcase.tr('.', '')).to_s =~ /^image\//
      json[:thumbnail_url] = project_node_attachment_path(current_project, @node, @attachment.filename)
    end

    render json: [json], content_type: 'text/plain'
  end

  # This function will send the Attachment file to the browser. It will try to
  # figure out if the file is an image in which case the attachment will be
  # displayed inline. By default the <tt>Content-disposition</tt> will be set to
  # +attachment+.
  def show
    filename = params[:filename]

    @attachment  = Attachment.find(filename, conditions: { node_id: @node.id })
    send_options = { filename: @attachment.filename }

    # Figure out the best way of displaying the file (by default send it as
    # an attachment).
    extname = File.extname(filename)
    send_options[:disposition] = 'attachment'

    # File.extname() returns either an empty string or the extension with a
    # leading dot (e.g. '.pdf')
    if !extname.empty?
      # account for the possibility of this being an image and present the
      # attachment inline
      mime_type = Mime::Type.lookup_by_extension(extname[1..-1])
      if mime_type
        send_options[:type] = mime_type.to_s
        if mime_type =~ 'image' && !mime_type.svg?
          send_options[:disposition] = 'inline'
        end
      end
    end

    send_data(@attachment.read, send_options)

    @attachment.close
  end

  # Invoke this method to delete an Attachment from the server. It receives the
  # attachment's file name in the :id parameter and the corresponding node in
  # the :node_id parameter.
  def destroy
    filename = params[:filename]

    @attachment = Attachment.find(filename, conditions: { node_id: @node.id })
    @attachment.delete

    render json: { success: true }
  end

  private
  # For most of the operations of this controller we need to identify the Node
  # we are working with. This filter sets the @node instance variable if the
  # give :node_id is valid.
  def find_or_initialize_node
    begin
      @node = current_project.nodes.find(params[:node_id])
    rescue
      redirect_to root_path, alert: 'Node not found'
    end
  end

  def attachment_params
    params.require(:attachment).permit(:filename)
  end
end
