Downloading and updating file content

app/decorators/upload_decorator.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+class UploadDecorator < Draper::Decorator
+  attr_reader :original_filename
+  delegate_all
+  def initialize(file, original_filename)
+    super(file)
+    @original_filename = original_filename
+  end
+end

app/services/file_appender.rb

@@ -9,6 +9,9 @@ def initialize(storage_adapter:, persister:, files:)
 
   def append_to(resource)
     return [] if files.blank?
+    updated_files = update_files(resource, files)
+    return updated_files unless updated_files.empty?
+
     file_sets = build_file_sets || file_nodes
     if resource.respond_to?(:file_metadata)
       resource.file_metadata += file_sets
@@ -20,6 +23,15 @@ def append_to(resource)
     file_sets
   end
 
+  def update_files(resource, files)
+    files.select { |file| file.is_a?(Hash) }.map do |file|
+      node = resource.file_metadata.select { |x| x.id.to_s == file.keys.first }.first
+      file_wrapper = UploadDecorator.new(file.values.first, node.original_filename.first)
+      file = storage_adapter.upload(file: file_wrapper, resource: node)
+      node
+    end
+  end
+
   def build_file_sets
     return if processing_derivatives?
     file_nodes.each_with_index.map do |node, index|

app/views/catalog/_admin_controls.html.erb

@@ -1,3 +1,27 @@
+<% if resource.kind_of?(FileSet) %>
+  <h2>Files</h2>
+  <%= simple_form_for FileSetChangeSet.new(resource) do |f| %>
+    <table class="table table-striped files">
+      <tr>
+       <th>Label</th>
+       <th>Download</th>
+       <th>Update</th>
+      </tr>
+      <% resource.file_metadata.each do |file| %>
+        <tr>
+          <td><%= file.label.first %></td>
+          <td><%= link_to "Download", valhalla.download_path(resource.id, file.id) %></td>
+          <td><%= f.input "files[][#{file.id}]", as: :file, label: false, required: false %></td>
+        </tr>
+      <% end %>
+      <tr>
+        <td colspan="2"></td>
+        <td><%= f.submit 'Update Files', class: 'btn btn-primary' %></td>
+      </tr>
+    </table>
+  <% end %>
+<% end %>
+
   <div class="form-actions">
     <%= link_to "Edit This #{resource.human_readable_type}", main_app.polymorphic_path([:edit, resource]), class: 'btn btn-default' %>
     <% if decorated_resource.manageable_files? %>

config/routes.rb

@@ -76,6 +76,7 @@
   get "/iiif/lookup/:prefix/:naan/:arkid", to: 'catalog#lookup_manifest', as: :lookup_manifest
 
   mount BrowseEverything::Engine => '/browse'
+  mount Valhalla::Engine => '/'
 
   if Rails.env.development? || Rails.env.test?
     mount Riiif::Engine => '/image-service', as: 'riiif'

spec/change_set_persisters/plum_change_set_persister_spec.rb

@@ -157,6 +157,30 @@
       expect(query_service.find_all.to_a.map(&:class)).to contain_exactly ScannedResource, FileSet
     end
   end
+  describe "updating files" do
+    let(:file1) { fixture_file_upload('files/example.tif', 'image/tiff') }
+    let(:file2) { fixture_file_upload('files/holding_locations.json', 'application/json') }
+    it "can append files as FileSets", run_real_derivatives: true do
+      # upload a file
+      resource = FactoryGirl.build(:scanned_resource)
+      change_set = change_set_class.new(resource)
+      change_set.files = [file1]
+      output = change_set_persister.save(change_set: change_set)
+      file_set = query_service.find_members(resource: output).first
+      file_node = file_set.file_metadata.find { |x| x.use == [Valkyrie::Vocab::PCDMUse.OriginalFile] }
+      file = storage_adapter.find_by(id: file_node.file_identifiers.first)
+      expect(file.size).to eq 196_882
+
+      # update the file
+      change_set = FileSetChangeSet.new(file_set)
+      change_set.files = [{ file_node.id.to_s => file2 }]
+      change_set_persister.save(change_set: change_set)
+      updated_file_set = query_service.find_by(id: file_set.id)
+      updated_file_node = updated_file_set.file_metadata.find { |x| x.id == file_node.id }
+      updated_file = storage_adapter.find_by(id: updated_file_node.file_identifiers.first)
+      expect(updated_file.size).to eq 5600
+    end
+  end
 
   describe "collection interactions" do
     context "when a collection is deleted" do

spec/controllers/valhalla/downloads_controller_spec.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+require 'rails_helper'
+
+RSpec.describe Valhalla::DownloadsController do
+  let(:meta) { Valkyrie.config.metadata_adapter }
+  let(:disk) { Valkyrie.config.storage_adapter }
+  let(:change_set_persister) { PlumChangeSetPersister.new(metadata_adapter: meta, storage_adapter: disk) }
+  let(:sample_file) { fixture_file_upload('files/example.tif', 'image/tiff') }
+  let(:resource) { FactoryGirl.create_for_repository(:scanned_resource, files: [sample_file]) }
+  let(:file_set) { resource.member_ids.map { |id| meta.query_service.find_by(id: id) }.first }
+  let(:file_node) { file_set.file_metadata.first }
+  let(:user) { FactoryGirl.create(:admin) }
+
+  routes { Valhalla::Engine.routes }
+
+  describe 'GET /downloads/:obj/file/:id' do
+    context "when logged in" do
+      before do
+        sign_in user if user
+      end
+
+      it "serves files that exist" do
+        get :show, params: { resource_id: file_set.id.to_s, id: file_node.id.to_s }
+        expect(response.body).to eq(sample_file.read)
+        expect(response.content_length).to eq(196_882)
+        expect(response.content_type).to eq('image/tiff')
+        expect(response.headers['Content-Disposition']).to eq('inline; filename="example.tif"')
+      end
+
+      it "returns an appropriate error when the file doesn't exist" do
+        get :show, params: { resource_id: file_set.id.to_s, id: 'bogus' }
+        expect(response.status).to eq(404)
+      end
+
+      it "returns an appropriate error when the resource doesn't exist" do
+        get :show, params: { resource_id: 'bogus', id: 'bogus' }
+        expect(response.status).to eq(404)
+      end
+    end
+
+    context "when not logged in" do
+      it "redirects to login" do
+        get :show, params: { resource_id: file_set.id.to_s, id: file_node.id.to_s }
+        expect(response).to redirect_to('/users/auth/cas')
+      end
+    end
+  end
+end

valhalla/app/controllers/valhalla/downloads_controller.rb

@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+class Valhalla::DownloadsController < ApplicationController
+  include Hydra::Controller::DownloadBehavior
+
+  def show
+    if resource && load_file
+      send_content
+    else
+      render_404
+    end
+  end
+
+  def resource
+    @resource ||= query_service.find_by(id: params[:resource_id])
+  rescue Valkyrie::Persistence::ObjectNotFoundError
+    nil
+  end
+
+  def load_file
+    return unless binary_file && file_desc
+    @load_file ||= FileWithMetadata.new(id: params[:id], file: binary_file, mime_type: file_desc.mime_type, original_name: file_desc.original_filename.first)
+  end
+
+  def file_desc
+    return unless resource
+    @file_desc ||= resource.file_metadata.find { |m| m.id.to_s == params[:id] }
+  end
+
+  def binary_file
+    return unless file_desc
+    @binary_file ||= storage_adapter.find_by(id: file_desc.file_identifiers.first)
+  end
+
+  class FileWithMetadata < Dry::Struct
+    delegate :size, :read, :stream, to: :file
+    attribute :id, Valkyrie::Types::Any
+    attribute :file, Valkyrie::Types::Any
+    attribute :mime_type, Valkyrie::Types::SingleValuedString
+    attribute :original_name, Valkyrie::Types::SingleValuedString
+  end
+
+  # Customize the :download ability in your Ability class, or override this method
+  def authorize_download!
+    authorize! :download, resource
+  end
+
+  # Copied from hydra-head and adjusted to handle the fact that we don't have a
+  # modified_date in Valkyrie yet.
+  def prepare_file_headers
+    send_file_headers! content_options
+    response.headers['Content-Type'] = file_desc.mime_type.first.to_s
+    response.headers['Content-Length'] ||= binary_file.size.to_s
+    # Prevent Rack::ETag from calculating a digest over body
+    response.headers['Last-Modified'] = modified_date
+  end
+
+  def modified_date
+    return unless load_file.respond_to?(:updated_at)
+    # Copied/pasted from Hydra-Head.
+    file_desc.updated_at.utc.strftime("%a, %d %b %Y %T GMT")
+  end
+
+  def query_service
+    Valkyrie.config.metadata_adapter.query_service
+  end
+
+  def storage_adapter
+    Valkyrie.config.storage_adapter
+  end
+end

valhalla/config/routes.rb

@@ -1,3 +1,4 @@
 # frozen_string_literal: true
 Valhalla::Engine.routes.draw do
+  get '/downloads/:resource_id/file/:id', to: 'downloads#show', as: :download
 end