Show author names in problem and translation views

app/models/problem.rb

@@ -4,7 +4,8 @@ class Problem < ApplicationRecord
   delegate :title, :content, to: :translation
 
   has_many :translations, inverse_of: :problem
-  
+  has_many :authors, -> { where(translations: { status: [:in_use, :outdated] }).distinct }, through: :translations
+
   self.per_page = 50
 
   def is_translated?
@@ -19,6 +20,10 @@ class Problem < ApplicationRecord
     self.translation.in_use!
   end
 
+  def has_anonymous_author?
+    translations.where(status: [:in_use, :outdated], author: nil).any?
+  end
+
   def original_url
     "https://projecteuler.net/problem=#{self.id}"
   end

app/models/translation.rb

@@ -1,5 +1,6 @@
 class Translation < ApplicationRecord
   belongs_to :problem, inverse_of: :translations
+  belongs_to :author, class_name: 'User', inverse_of: :translations, optional: true
   enum status: [:pending, :in_use, :outdated, :declined]
 
   validates :title, :content, :problem_id, presence: true
@@ -7,6 +8,10 @@ class Translation < ApplicationRecord
 
   self.per_page = 50
 
+  def has_author?
+    !!self.author
+  end
+
   def title_is_unique_among_other_problems
     Problem.includes(:translation).where.not(id: problem_id).each do |problem|
       if problem.is_translated? and problem.title == title

app/models/user.rb

@@ -2,6 +2,7 @@ class User < ApplicationRecord
   devise :omniauthable, :rememberable
 
   enum role: [:user, :admin]
+  has_many :translations, inverse_of: :author, dependent: :nullify
 
   def self.from_omniauth(auth)
     where(provider: auth.provider, uid: auth.uid).first_or_create do |user|