FEATURE: Groundwork for user-selectable theme components

* Phase 0 for user-selectable theme components

- Drops `key` column from the `themes` table
- Drops `theme_key` column from the `user_options` table
- Adds `theme_ids` (array of ints default []) column to the `user_options` table and migrates data from `theme_key` to the new column.
- Removes the `default_theme_key` site setting and adds `default_theme_id` instead.
- Replaces `theme_key` cookie with a new one called `theme_ids`
- no longer need Theme.settings_for_client

spec/components/middleware/anonymous_cache_spec.rb

@@ -34,12 +34,12 @@ describe Middleware::AnonymousCache::Helper do
     it "handles theme keys" do
       theme = Theme.create(name: "test", user_id: -1, user_selectable: true)
 
-      with_bad_theme_key = new_helper("HTTP_COOKIE" => "theme_key=abc").cache_key
+      with_bad_theme_key = new_helper("HTTP_COOKIE" => "theme_ids=abc").cache_key
       with_no_theme_key = new_helper().cache_key
 
       expect(with_bad_theme_key).to eq(with_no_theme_key)
 
-      with_good_theme_key = new_helper("HTTP_COOKIE" => "theme_key=#{theme.key}").cache_key
+      with_good_theme_key = new_helper("HTTP_COOKIE" => "theme_ids=#{theme.id}").cache_key
 
       expect(with_good_theme_key).not_to eq(with_no_theme_key)
     end

spec/components/stylesheet/manager_spec.rb

@@ -9,7 +9,7 @@ describe Stylesheet::Manager do
     expect(link).to eq("")
 
     theme = Theme.create(name: "embedded", user_id: -1)
-    SiteSetting.default_theme_key = theme.key
+    SiteSetting.default_theme_id = theme.id
 
     link = Stylesheet::Manager.stylesheet_link_tag(:embedded_theme)
     expect(link).not_to eq("")
@@ -41,9 +41,9 @@ describe Stylesheet::Manager do
 
     theme.add_child_theme!(child_theme)
 
-    old_link = Stylesheet::Manager.stylesheet_link_tag(:desktop_theme, 'all', theme.key)
+    old_link = Stylesheet::Manager.stylesheet_link_tag(:desktop_theme, 'all', theme.id)
 
-    manager = Stylesheet::Manager.new(:desktop_theme, theme.key)
+    manager = Stylesheet::Manager.new(:desktop_theme, theme.id)
     manager.compile(force: true)
 
     css = File.read(manager.stylesheet_fullpath)
@@ -57,7 +57,7 @@ describe Stylesheet::Manager do
     child_theme.set_field(target: :desktop, name: :scss, value: ".nothing{color: green;}")
     child_theme.save!
 
-    new_link = Stylesheet::Manager.stylesheet_link_tag(:desktop_theme, 'all', theme.key)
+    new_link = Stylesheet::Manager.stylesheet_link_tag(:desktop_theme, 'all', theme.id)
 
     expect(new_link).not_to eq(old_link)
 
@@ -77,12 +77,12 @@ describe Stylesheet::Manager do
         user_id: -1
       )
 
-      manager = Stylesheet::Manager.new(:desktop_theme, theme.key)
+      manager = Stylesheet::Manager.new(:desktop_theme, theme.id)
       digest1 = manager.digest
 
       DiscoursePluginRegistry.stylesheets.add "fake_file"
 
-      manager = Stylesheet::Manager.new(:desktop_theme, theme.key)
+      manager = Stylesheet::Manager.new(:desktop_theme, theme.id)
       digest2 = manager.digest
 
       expect(digest1).not_to eq(digest2)
@@ -107,7 +107,7 @@ describe Stylesheet::Manager do
         type_id: ThemeField.types[:theme_upload_var]
       )
 
-      manager = Stylesheet::Manager.new(:desktop_theme, theme.key)
+      manager = Stylesheet::Manager.new(:desktop_theme, theme.id)
       digest1 = manager.digest
       field.destroy!
 
@@ -121,7 +121,7 @@ describe Stylesheet::Manager do
         type_id: ThemeField.types[:theme_upload_var]
       )
 
-      manager = Stylesheet::Manager.new(:desktop_theme, theme.key)
+      manager = Stylesheet::Manager.new(:desktop_theme, theme.id)
       digest2 = manager.digest
 
       expect(digest1).not_to eq(digest2)
@@ -137,7 +137,7 @@ describe Stylesheet::Manager do
       category1 = Fabricate(:category, uploaded_background_id: 123, updated_at: 1.week.ago)
       category2 = Fabricate(:category, uploaded_background_id: 456, updated_at: 2.days.ago)
 
-      manager = Stylesheet::Manager.new(:desktop_theme, theme.key)
+      manager = Stylesheet::Manager.new(:desktop_theme, theme.id)
 
       digest1 = manager.color_scheme_digest
 

spec/components/wizard/step_updater_spec.rb

@@ -155,7 +155,7 @@ 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)
+        theme = Theme.find_by(id: SiteSetting.default_theme_id)
         expect(theme.color_scheme.base_scheme_id).to eq('dark')
       end
     end
@@ -203,7 +203,7 @@ describe Wizard::StepUpdater do
         expect(color_scheme).to be_present
         expect(color_scheme.colors).to be_present
 
-        theme = Theme.find_by(key: SiteSetting.default_theme_key)
+        theme = Theme.find_by(id: SiteSetting.default_theme_id)
         expect(theme.color_scheme_id).to eq(color_scheme.id)
 
         expect(Theme.where(user_selectable: true).count).to eq(2)