Add S3 upload field to video edit form

dashboard/app/controllers/videos_controller.rb

@@ -37,10 +37,12 @@ def new
   end
 
   def edit
+    @s3_metadata = Video.s3_metadata(@video.download)
   end
 
   def create
-    @video = Video.new(video_params)
+    filename = upload_to_s3
+    @video = Video.new(video_params.merge(download: "https://videos.code.org/#{filename}"))
 
     if @video.save
       Video.merge_and_write_i18n({@video.key => i18n_params[:title]})
@@ -55,7 +57,9 @@ def create
   # PATCH/PUT /videos/1
   # PATCH/PUT /videos/1.json
   def update
-    if @video.update(video_params)
+    filename = upload_to_s3
+
+    if @video.update(video_params.merge(download: "https://videos.code.org/#{filename}"))
       Video.merge_and_write_i18n({@video.key => i18n_params[:title]})
       Video.merge_and_write_attributes(@video.key, @video.youtube_code, @video.download)
 
@@ -67,6 +71,19 @@ def update
 
   private
 
+  def upload_to_s3
+    raise 'Expected a video/mp4 (.mp4) file' unless video_params[:download].content_type == 'video/mp4'
+
+    filename = File.basename(video_params[:download].original_filename).parameterize + '.mp4'
+    AWS::S3.upload_to_bucket(
+      'videos.code.org',
+      "levelbuilder/#{filename}",
+      video_params[:download],
+      acl: 'public-read',
+      no_random: true,
+    )
+  end
+
   def allow_iframe
     response.headers['X-Frame-Options'] = 'ALLOWALL'
   end

dashboard/app/models/video.rb

@@ -17,6 +17,7 @@ class Video < ActiveRecord::Base
   default_scope {order(:key)}
 
   validates_uniqueness_of :key
+  validates_presence_of :download
 
   before_save :fetch_thumbnail
 
@@ -74,6 +75,13 @@ def self.youtube_base_url
     'https://www.youtube.com'
   end
 
+  def self.s3_metadata(url)
+    key = url.sub(/^https?:\/\/videos.code.org\//, '')
+    AWS::S3.create_client.head_object(bucket: 'videos.code.org', key: key)
+  rescue Aws::S3::Errors::NoSuchKey
+    {}
+  end
+
   def fetch_thumbnail
     return unless Rails.application.config.levelbuilder_mode
 

dashboard/app/views/videos/_form.html.haml

@@ -21,7 +21,16 @@
     = f.text_field :youtube_code
   .field
     = f.label 'S3 download link'
+    - if @s3_metadata.present?
+      %p
+        = link_to @video.download, @video.download
+      %p
+        Size:
+        = number_to_human_size(@s3_metadata.content_length)
+      %p{title: @s3_metadata.last_modified.to_formatted_s(:long_ordinal)}
+        Last modified:
+        = time_ago_in_words(@s3_metadata.last_modified) + ' ago'
     %br/
-    = f.text_field :download
+    = f.file_field :download, style: 'line-height: initial'
   .actions
     = f.submit