2 files changed, 88 insertions, 1 deletions
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index e8dd61e493f..7d87197a270 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -35,7 +35,7 @@ module API
       expose :confirmed_at
       expose :last_activity_on
       expose :email
-      expose :color_scheme_id, :projects_limit, :current_sign_in_at
+      expose :theme_id, :color_scheme_id, :projects_limit, :current_sign_in_at
       expose :identities, using: Entities::Identity
       expose :can_create_group?, as: :can_create_group
       expose :can_create_project?, as: :can_create_project
diff --git a/lib/gitlab/themes.rb b/lib/gitlab/themes.rb
new file mode 100644
index 00000000000..19ab76ae80f
--- /dev/null
+++ b/lib/gitlab/themes.rb
@@ -0,0 +1,87 @@
+module Gitlab
+  # Module containing GitLab's application theme definitions and helper methods
+  # for accessing them.
+  module Themes
+    extend self
+
+    # Theme ID used when no `default_theme` configuration setting is provided.
+    APPLICATION_DEFAULT = 2
+
+    # Struct class representing a single Theme
+    Theme = Struct.new(:id, :name, :css_class)
+
+    # All available Themes
+    THEMES = [
+      Theme.new(1, 'Graphite', 'ui_graphite'),
+      Theme.new(2, 'Charcoal', 'ui_charcoal'),
+      Theme.new(3, 'Green',    'ui_green'),
+      Theme.new(4, 'Black',    'ui_black'),
+      Theme.new(5, 'Violet',   'ui_violet'),
+      Theme.new(6, 'Blue',     'ui_blue')
+    ].freeze
+
+    # Convenience method to get a space-separated String of all the theme
+    # classes that might be applied to the `body` element
+    #
+    # Returns a String
+    def body_classes
+      THEMES.collect(&:css_class).uniq.join(' ')
+    end
+
+    # Get a Theme by its ID
+    #
+    # If the ID is invalid, returns the default Theme.
+    #
+    # id - Integer ID
+    #
+    # Returns a Theme
+    def by_id(id)
+      THEMES.detect { |t| t.id == id } || default
+    end
+
+    # Returns the number of defined Themes
+    def count
+      THEMES.size
+    end
+
+    # Get the default Theme
+    #
+    # Returns a Theme
+    def default
+      by_id(default_id)
+    end
+
+    # Iterate through each Theme
+    #
+    # Yields the Theme object
+    def each(&block)
+      THEMES.each(&block)
+    end
+
+    # Get the Theme for the specified user, or the default
+    #
+    # user - User record
+    #
+    # Returns a Theme
+    def for_user(user)
+      if user
+        by_id(user.theme_id)
+      else
+        default
+      end
+    end
+
+    private
+
+    def default_id
+      id = Gitlab.config.gitlab.default_theme.to_i
+
+      # Prevent an invalid configuration setting from causing an infinite loop
+      if id < THEMES.first.id || id > THEMES.last.id
+        APPLICATION_DEFAULT
+      else
+        id
+      end
+    end
+  end
+end