FEATURE: out-of-the-box dark/light user selectable themes

app/models/color_scheme.rb

@@ -92,13 +92,19 @@ class ColorScheme < ActiveRecord::Base
   # create_from_base will create a new ColorScheme that overrides Discourse's base color scheme with the given colors.
   def self.create_from_base(params)
     new_color_scheme = new(name: params[:name])
-    colors = base.colors_hashes
+    new_color_scheme.via_wizard = true if params[:via_wizard]
+    new_color_scheme.base_scheme_id = params[:base_scheme_id]
+
+    colors = CUSTOM_SCHEMES[params[:base_scheme_id].to_sym]&.map do |name, hex|
+      {name: name, hex: hex}
+    end if params[:base_scheme_id]
+    colors ||= base.colors_hashes
 
     # Override base values
     params[:colors].each do |name, hex|
       c = colors.find {|x| x[:name].to_s == name.to_s}
       c[:hex] = hex
-    end
+    end if params[:colors]
 
     new_color_scheme.colors = colors
     new_color_scheme.save

app/models/theme.rb

@@ -83,6 +83,10 @@ class Theme < ActiveRecord::Base
     Theme.expire_site_cache!
   end
 
+  def default?
+    SiteSetting.default_theme_key == key
+  end
+
   def self.lookup_field(key, target, field)
     return if key.blank?
 

config/locales/server.en.yml

@@ -2772,6 +2772,9 @@ en:
     base_theme_name: "Base"
     default: "Light Scheme"
     dark: "Dark Scheme"
+    default_theme_name: "Default"
+    dark_theme_name: "Dark"
+    light_theme_name: "Light"
 
   about: "About"
   guidelines: "Guidelines"

db/fixtures/600_themes.rb

@@ -0,0 +1,19 @@
+# we can not guess what to do if customization already started, so skip it
+if !Theme.exists?
+  STDERR.puts "> Seeding dark and light themes"
+
+  name = I18n.t("wizard.step.colors.fields.theme_id.choices.dark.label")
+  dark_scheme = ColorScheme.where.find_by(base_scheme_id: "dark")
+  dark_scheme ||= ColorScheme.create_from_base(name: name, via_wizard: true, base_scheme_id: "dark")
+
+  name = I18n.t('color_schemes.dark_theme_name')
+  _dark_theme =  Theme.create(name: name, user_id: -1,
+                                         color_scheme_id: dark_scheme.id,
+                                         user_selectable: true)
+
+  name = I18n.t('color_schemes.default_theme_name')
+  default_theme =  Theme.create(name: name, user_id: -1,
+                                         user_selectable: true)
+
+  default_theme.set_default!
+end

lib/wizard/builder.rb

@@ -114,8 +114,8 @@ class Wizard
       end
 
       @wizard.append_step('colors') do |step|
-        scheme_id = ColorScheme.where(via_wizard: true).pluck(:base_scheme_id)&.first
-        scheme_id ||= 'default'
+        default_theme = Theme.find_by(key: SiteSetting.default_theme_key)
+        scheme_id = default_theme&.color_scheme&.base_scheme_id || 'default'
 
         themes = step.add_field(id: 'base_scheme_id', type: 'dropdown', required: true, value: scheme_id)
         ColorScheme.base_color_scheme_colors.each do |t|
@@ -128,37 +128,28 @@ class Wizard
         step.on_update do |updater|
           scheme_name = updater.fields[:base_scheme_id]
 
-          theme = ColorScheme.base_color_schemes.find{|s| s.base_scheme_id == scheme_name}
+          theme = nil
 
-          colors = []
-          theme.colors.each do |color|
-            colors << {name: color.name, hex: color.hex }
-          end
+          if scheme_name == "dark"
+            scheme = ColorScheme.find_by(base_scheme_id: 'dark', via_wizard: true)
 
-          attrs = {
-            name: I18n.t("wizard.step.colors.fields.theme_id.choices.#{scheme_name}.label"),
-            colors: colors,
-            base_scheme_id: scheme_name
-          }
+            name = I18n.t("wizard.step.colors.fields.theme_id.choices.dark.label")
+            scheme ||= ColorScheme.create_from_base(name: name, via_wizard: true, base_scheme_id: "dark")
 
-          scheme = ColorScheme.where(via_wizard: true).first
-          if scheme.present?
-            attrs[:colors] = colors
-            revisor = ColorSchemeRevisor.new(scheme, attrs)
-            revisor.revise
+            theme = Theme.find_by(color_scheme_id: scheme.id)
+            name = I18n.t('color_schemes.dark_theme_name')
+            theme ||= Theme.create(name: name, color_scheme_id: scheme.id)
           else
-            attrs[:via_wizard] = true
-            scheme = ColorScheme.new(attrs)
-            scheme.save!
+
+            themes = Theme.where(color_scheme_id: nil).order(:id).to_a
+            theme = themes.find(&:default?)
+            theme ||= themes.first
+
+            name = I18n.t('color_schemes.light_theme_name')
+            theme ||= Theme.create(name: name)
           end
 
-          default_theme = Theme.find_by(key: SiteSetting.default_theme_key)
-          unless default_theme
-            default_theme = Theme.new(name: "Default Theme", user_id: -1)
-          end
-          default_theme.color_scheme_id = scheme.id
-          default_theme.save!
-          SiteSetting.default_theme_key = default_theme.key
+          theme.set_default!
         end
       end
 

spec/components/stylesheet/manager_spec.rb

@@ -4,6 +4,7 @@ require 'stylesheet/compiler'
 describe Stylesheet::Manager do
 
   it 'does not crash for missing theme' do
+    Theme.clear_default!
     link = Stylesheet::Manager.stylesheet_link_tag(:embedded_theme)
     expect(link).to eq("")
 

spec/components/wizard/step_updater_spec.rb

@@ -155,17 +155,14 @@ describe Wizard::StepUpdater do
         updater.update
         expect(updater.success?).to eq(true)
         expect(wizard.completed_steps?('colors')).to eq(true)
-
-
         theme = Theme.find_by(key: SiteSetting.default_theme_key)
-        expect(theme.color_scheme_id).to eq(color_scheme.id)
-
+        expect(theme.color_scheme.base_scheme_id).to eq('dark')
       end
     end
 
     context "without an existing scheme" do
       it "creates the scheme" do
-        updater = wizard.create_updater('colors', base_scheme_id: 'dark')
+        updater = wizard.create_updater('colors', base_scheme_id: 'dark', allow_dark_light_selection: true)
         updater.update
         expect(updater.success?).to eq(true)
         expect(wizard.completed_steps?('colors')).to eq(true)
@@ -176,6 +173,8 @@ describe Wizard::StepUpdater do
 
         theme = Theme.find_by(key: SiteSetting.default_theme_key)
         expect(theme.color_scheme_id).to eq(color_scheme.id)
+
+        expect(Theme.where(user_selectable: true).count).to eq(2)
       end
     end
   end

spec/controllers/admin/themes_controller_spec.rb

@@ -12,7 +12,11 @@ describe Admin::ThemesController do
     end
 
     context ' .index' do
-      it 'returns success' do
+      it 'correctly returns themes' do
+
+        ColorScheme.destroy_all
+        Theme.destroy_all
+
         theme = Theme.new(name: 'my name', user_id: -1)
         theme.set_field(target: :common, name: :scss, value: '.body{color: black;}')
         theme.set_field(target: :desktop, name: :after_header, value: '<b>test</b>')

spec/models/stylesheet_cache_spec.rb

@@ -4,6 +4,8 @@ describe StylesheetCache do
 
   describe "add" do
     it "correctly cycles once MAX_TO_KEEP is hit" do
+      StylesheetCache.destroy_all
+
       (StylesheetCache::MAX_TO_KEEP + 1).times do |i|
         StylesheetCache.add("a", "d" + i.to_s, "c" + i.to_s, "map")
       end
@@ -13,6 +15,8 @@ describe StylesheetCache do
     end
 
     it "does nothing if digest is set and already exists" do
+      StylesheetCache.destroy_all
+
       StylesheetCache.add("a", "b", "c", "map")
       StylesheetCache.add("a", "b", "cc", "map")
 

spec/models/theme_spec.rb

@@ -152,6 +152,8 @@ HTML
   end
 
   it 'correctly caches theme keys' do
+    Theme.destroy_all
+
     theme = Theme.create!(name: "bob", user_id: -1)
 
     expect(Theme.theme_keys).to eq(Set.new([theme.key]))