FEATURE: auto grant an available title when removing old title

* FEATURE: auto grant an available title when removing old title

app/models/badge.rb

@@ -159,6 +159,15 @@ class Badge < ActiveRecord::Base
     SQL
   end
 
+  def self.i18n_name(name)
+    name.downcase.tr(' ', '_')
+  end
+
+  def self.display_name(name)
+    key = "badges.#{i18n_name(name)}.name"
+    I18n.t(key, default: name)
+  end
+
   def awarded_for_trust_level?
     id <= 4
   end
@@ -191,8 +200,7 @@ class Badge < ActiveRecord::Base
   end
 
   def display_name
-    key = "badges.#{i18n_name}.name"
-    I18n.t(key, default: self.name)
+    self.class.display_name(name)
   end
 
   def long_description
@@ -230,9 +238,8 @@ class Badge < ActiveRecord::Base
   end
 
   def i18n_name
-    self.name.downcase.tr(' ', '_')
+    @i18n_name ||= self.class.i18n_name(name)
   end
-
 end
 
 # == Schema Information

app/models/group_user.rb

@@ -5,7 +5,7 @@ class GroupUser < ActiveRecord::Base
   belongs_to :user
 
   after_save :update_title
-  after_destroy :remove_title
+  after_destroy :grant_other_available_title
 
   after_save :set_primary_group
   after_destroy :remove_primary_group, :recalculate_trust_level
@@ -43,13 +43,9 @@ class GroupUser < ActiveRecord::Base
     )
   end
 
-  def remove_title
-    if group.title.present?
-      DB.exec("
-        UPDATE users SET title = NULL
-        WHERE title = :title AND id = :id",
-        id: user_id, title: group.title
-      )
+  def grant_other_available_title
+    if group.title.present? && group.title == user.title
+      user.update!(title: user.next_best_title)
     end
   end
 
@@ -85,7 +81,6 @@ class GroupUser < ActiveRecord::Base
     user.update!(group_locked_trust_level: highest_level)
     Promotion.recalculate(user)
   end
-
 end
 
 # == Schema Information

app/models/user.rb

@@ -110,6 +110,7 @@ class User < ActiveRecord::Base
   before_save :update_username_lower
   before_save :ensure_password_is_hashed
   before_save :match_title_to_primary_group_changes
+  before_save :check_if_title_is_badged_granted
 
   after_save :expire_tokens_if_password_changed
   after_save :clear_global_notice_if_needed
@@ -1000,13 +1001,6 @@ class User < ActiveRecord::Base
     @user_fields
   end
 
-  def title=(val)
-    write_attribute(:title, val)
-    if !new_record? && user_profile
-      user_profile.update_column(:badge_granted_title, false)
-    end
-  end
-
   def number_of_deleted_posts
     Post.with_deleted
       .where(user_id: self.id)
@@ -1123,6 +1117,19 @@ class User < ActiveRecord::Base
     from_staged? && self.created_at && self.created_at < 1.day.ago
   end
 
+  def next_best_title
+    group_titles_query = groups.where("groups.title <> ''")
+    group_titles_query = group_titles_query.order("groups.id = #{primary_group_id} DESC") if primary_group_id
+    group_titles_query = group_titles_query.order("groups.primary_group DESC").limit(1)
+
+    if next_best_group_title = group_titles_query.pluck(:title).first
+      return next_best_group_title
+    end
+
+    next_best_badge_title = badges.where(allow_title: true).limit(1).pluck(:name).first
+    next_best_badge_title ? Badge.display_name(next_best_badge_title) : nil
+  end
+
   protected
 
   def badge_grant
@@ -1285,6 +1292,13 @@ class User < ActiveRecord::Base
 
   private
 
+  def check_if_title_is_badged_granted
+    if title_changed? && !new_record? && user_profile
+      badge_granted_title = title.present? && badges.where(allow_title: true, name: title).exists?
+      user_profile.update_column(:badge_granted_title, badge_granted_title)
+    end
+  end
+
   def previous_visit_at_update_required?(timestamp)
     seen_before? && (last_seen_at < (timestamp - SiteSetting.previous_visit_timeout_hours.hours))
   end

app/services/user_updater.rb

@@ -66,9 +66,6 @@ class UserUpdater
       attributes[:title] != user.title &&
       guardian.can_grant_title?(user, attributes[:title])
       user.title = attributes[:title]
-      if user.badges.where(name: user.title).exists?
-        user_profile.badge_granted_title = true
-      end
     end
 
     CATEGORY_IDS.each do |attribute, level|

spec/models/badge_spec.rb

@@ -80,4 +80,21 @@ describe Badge do
       it { is_expected.to be true }
     end
   end
+
+  describe '.i18n_name' do
+    it 'transforms to lower case letters, and replaces spaces with underscores' do
+      expect(Badge.i18n_name('Basic User')).to eq('basic_user')
+    end
+  end
+
+  describe '.display_name' do
+    it 'fetches from translations when i18n_name key exists' do
+      expect(Badge.display_name('basic_user')).to eq('Basic')
+      expect(Badge.display_name('Basic User')).to eq('Basic')
+    end
+
+    it 'fallbacks to argument value when translation does not exist' do
+      expect(Badge.display_name('Not In Translations')).to eq('Not In Translations')
+    end
+  end
 end

spec/models/group_spec.rb

@@ -675,13 +675,22 @@ describe Group do
   describe '#remove' do
     before { group.add(user) }
 
-    it "only strips user's title if exact match" do
-      group.update(title: 'Awesome')
-      expect { group.remove(user) }.to change { user.reload.title }.from('Awesome').to(nil)
+    context 'when stripping title' do
+      it "only strips user's title if exact match" do
+        group.update!(title: 'Awesome')
+        expect { group.remove(user) }.to change { user.reload.title }.from('Awesome').to(nil)
 
-      group.add(user)
-      user.update_columns(title: 'Different')
-      expect { group.remove(user) }.to_not change { user.reload.title }
+        group.add(user)
+        user.update_columns(title: 'Different')
+        expect { group.remove(user) }.to_not change { user.reload.title }
+      end
+
+      it "grants another title when the user has other available titles" do
+        group.update!(title: 'Awesome')
+        Fabricate(:group, title: 'Super').add(user)
+
+        expect { group.remove(user) }.to change { user.reload.title }.from('Awesome').to('Super')
+      end
     end
 
     it "unsets the user's primary group" do

spec/models/user_spec.rb

@@ -1826,4 +1826,75 @@ describe User do
       expect { user.update(primary_group: primary_group_a) }.to_not change { user.reload.title }
     end
   end
+
+  describe '#title=' do
+    let(:badge) { Fabricate(:badge, name: 'Badge', allow_title: false) }
+
+    it 'sets badge_granted_title correctly' do
+      BadgeGranter.grant(badge, user)
+
+      user.update!(title: badge.name)
+      expect(user.user_profile.reload.badge_granted_title).to eq(false)
+
+      user.update!(title: 'Custom')
+      expect(user.user_profile.reload.badge_granted_title).to eq(false)
+
+      badge.update!(allow_title: true)
+      user.update!(title: badge.name)
+      expect(user.user_profile.reload.badge_granted_title).to eq(true)
+
+      user.update!(title: nil)
+      expect(user.user_profile.reload.badge_granted_title).to eq(false)
+    end
+  end
+
+  describe '#next_best_title' do
+    let(:group_a) { Fabricate(:group, title: 'Group A') }
+    let(:group_b) { Fabricate(:group, title: 'Group B') }
+    let(:group_c) { Fabricate(:group, title: 'Group C') }
+    let(:badge) { Fabricate(:badge, name: 'Badge', allow_title: true) }
+
+    it 'only includes groups with title' do
+      group_a.add(user)
+      expect(user.next_best_title).to eq('Group A')
+
+      group_a.update!(title: nil)
+      expect(user.next_best_title).to eq(nil)
+    end
+
+    it 'only includes badges that allow to be set as title' do
+      BadgeGranter.grant(badge, user)
+      expect(user.next_best_title).to eq('Badge')
+
+      badge.update!(allow_title: false)
+      expect(user.next_best_title).to eq(nil)
+    end
+
+    it "picks the next best title in the order: user's primary group, primary group, groups, and badges" do
+      group_a.add(user)
+      group_b.add(user)
+      group_c.add(user)
+      BadgeGranter.grant(badge, user)
+
+      group_a.update!(primary_group: true)
+      group_b.update!(primary_group: true)
+      user.update!(primary_group_id: group_a.id)
+      expect(user.next_best_title).to eq('Group A')
+
+      user.update!(primary_group_id: group_b.id)
+      expect(user.next_best_title).to eq('Group B')
+
+      group_b.remove(user)
+      expect(user.next_best_title).to eq('Group A')
+
+      group_a.remove(user)
+      expect(user.next_best_title).to eq('Group C')
+
+      group_c.remove(user)
+      expect(user.next_best_title).to eq('Badge')
+
+      BadgeGranter.revoke(UserBadge.find_by(user_id: user.id, badge_id: badge.id))
+      expect(user.next_best_title).to eq(nil)
+    end
+  end
 end