Allow users to have multiple themes

app/helpers/theme_helper.rb

@@ -52,7 +52,7 @@ module ThemeHelper
   end
 
   def theme_color
-    theme = active_theme_user&.theme
+    theme = active_theme_user&.active_theme
     if theme
       theme.theme_color
     else
@@ -61,7 +61,7 @@ module ThemeHelper
   end
 
   def mobile_theme_color
-    theme = active_theme_user&.theme
+    theme = active_theme_user&.active_theme
     if theme
       theme.mobile_theme_color
     else
@@ -72,7 +72,7 @@ module ThemeHelper
   def active_theme_user
     user = @user || @answer&.user # rubocop:disable Rails/HelperInstanceVariable
 
-    if user&.theme.present? && should_show_foreign_theme?
+    if user&.active_theme.present? && should_show_foreign_theme?
       user
     elsif user_signed_in?
       current_user

app/models/user.rb

@@ -41,13 +41,14 @@ class User < ApplicationRecord
   has_many :list_memberships, class_name: "ListMember", dependent: :destroy_async
   has_many :mute_rules, dependent: :destroy_async
   has_many :anonymous_blocks, dependent: :destroy_async
+  has_many :themes, dependent: :destroy
 
   has_many :subscriptions, dependent: :destroy_async
   has_many :totp_recovery_codes, dependent: :destroy_async
   has_many :web_push_subscriptions, dependent: :destroy_async
 
   has_one :profile, dependent: :destroy
-  has_one :theme, dependent: :destroy
+  has_one :active_theme, -> { where(active: true) }, class_name: "Theme"
 
   has_many :bans, class_name: "UserBan", dependent: :destroy_async
   has_many :banned_users, class_name:  "UserBan",

app/views/settings/theme/edit.html.haml

@@ -4,10 +4,10 @@
     %p.lead= t(".lead")
     = t(".body_html")
 
-    - if current_user.theme
+    - if current_user.active_theme
       .pull-right
         = link_to t(".delete"), settings_theme_path, data: { turbo_confirm: t("voc.confirm"), turbo_method: :delete }, tabindex: -1, class: "btn btn-danger"
-= bootstrap_form_for(current_user.theme || Theme.new,
+= bootstrap_form_for(current_user.active_theme || Theme.new,
   html: { id: "update" },
   method: :patch,
   data: { turbo: false, controller: "theme", action: "theme#submit" }) do |f|

db/migrate/20231220130817_allow_multiple_themes.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class AllowMultipleThemes < ActiveRecord::Migration[7.0]
+  def up
+    change_table :themes, bulk: true do |t|
+      t.boolean :active, default: true, null: false
+      t.string :name, null: true
+    end
+
+    change_column :themes, :active, :boolean, default: false, null: false
+
+    add_index :themes, %i[user_id active]
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2023_12_20_100445) do
+ActiveRecord::Schema[7.0].define(version: 2023_12_20_130817) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -292,6 +292,9 @@ ActiveRecord::Schema[7.0].define(version: 2023_12_20_100445) do
     t.integer "input_placeholder", default: 7107965, null: false
     t.integer "raised_text", default: 0, null: false
     t.integer "raised_accent_text", default: 0, null: false
+    t.boolean "active", default: false, null: false
+    t.string "name"
+    t.index ["user_id", "active"], name: "index_themes_on_user_id_and_active"
     t.index ["user_id"], name: "index_themes_on_user_id"
   end