Suggest closest contestant name when converting a message to completion

app/controllers/messages_controller.rb

@@ -74,7 +74,6 @@ class MessagesController < ApplicationController
     @action_name = t("helpers.buttons.back")
     @action_path = contest_path(@contest)
 
-    @message = Message.find(params[:message_id])
     @completion = Completion.new()
     @completion.display_time_from_start = @message.display_time
 
@@ -96,7 +95,19 @@ class MessagesController < ApplicationController
   end
 
   def set_data
-    @contestants = @contest.contestants.order(:name)
+    @message = Message.find(params[:message_id])
     @puzzles = @contest.puzzles
+    @contestants = @contest.contestants.order(:name)
+    if @contestants.size > 0
+      @closest_contestant = @contestants.first
+      closest_distance = 10000
+      @contestants.each do |contestant|
+        distance = DamerauLevenshtein.distance(@message.author, contestant.name)
+        if distance < closest_distance
+          closest_distance = distance
+          @closest_contestant = contestant
+        end
+      end
+    end
   end
 end

app/views/completions/_form.html.slim

@@ -22,6 +22,10 @@
       .form-floating
         = form.select :contestant_id, @contestants.map { |contestant| [contestant.form_name, contestant.id] }, {}, class: "form-select"
         = form.label :contestant_id
+  - if @closest_contestant
+    javascript:
+      el = document.querySelector('select[name="completion[contestant_id]"]');
+      el.value = "#{@closest_contestant.id}"
   - if @puzzles.size > 1
     .row.mb-3
       .col