post replacements: add option to fix source after replacement.

Adds a "Final Source" field to the post replacement dialog. If
specified, the post's source field will be changed to this value after
replacement.

This makes fixing the source back to the HTML page after
replacement easier.

app/controllers/post_replacements_controller.rb

@@ -23,6 +23,6 @@ class PostReplacementsController < ApplicationController
 
 private
   def create_params
-    params.require(:post_replacement).permit(:replacement_url)
+    params.require(:post_replacement).permit(:replacement_url, :final_source)
   end
 end

app/models/post_replacement.rb

@@ -4,7 +4,8 @@ class PostReplacement < ApplicationRecord
   belongs_to :post
   belongs_to :creator, class_name: "User"
   before_validation :initialize_fields
-  attr_accessible :replacement_url
+  attr_accessible :replacement_url, :final_source
+  attr_accessor :final_source
 
   def initialize_fields
     self.creator = CurrentUser.user
@@ -37,7 +38,7 @@ class PostReplacement < ApplicationRecord
       post.image_width = upload.image_width
       post.image_height = upload.image_height
       post.file_size = upload.file_size
-      post.source = upload.source
+      post.source = final_source.presence || upload.source
       post.tag_string = upload.tag_string
       rescale_notes
       update_ugoira_frame_data(upload)

app/views/post_replacements/_new.html.erb

@@ -1,5 +1,6 @@
 <%= format_text(WikiPage.titled(Danbooru.config.replacement_notice_wiki_page).first.try(&:body), ragel: true) %>
 
 <%= simple_form_for(post_replacement, url: post_replacements_path(post_id: post_replacement.post_id), method: :post) do |f| %>
-  <%= f.input :replacement_url, label: "New Source", input_html: { value: "" } %>
+  <%= f.input :replacement_url, label: "Replacement URL", hint: "The source URL to download the replacement from.", as: :string, input_html: { value: post_replacement.post.normalized_source } %>
+  <%= f.input :final_source, label: "Final Source", hint: "If present, the source field will be changed to this after replacement.", as: :string, input_html: { value: post_replacement.post.source } %>
 <% end %>

test/unit/post_replacement_test.rb

@@ -190,5 +190,15 @@ class PostReplacementTest < ActiveSupport::TestCase
         assert(File.exists?(@post.large_file_path))
       end
     end
+
+    context "a post when given a final_source" do
+      should "change the source to the final_source" do
+        replacement_url = "http://data.tumblr.com/afed9f5b3c33c39dc8c967e262955de2/tumblr_orwwptNBCE1wsfqepo1_raw.png"
+        final_source = "https://noizave.tumblr.com/post/162094447052"
+        @post.replace!(replacement_url: replacement_url, final_source: final_source)
+
+        assert_equal(final_source, @post.source)
+      end
+    end
   end
 end