1 files changed, 84 insertions, 0 deletions
diff --git a/lib/gitlab/themes.rb b/lib/gitlab/themes.rb
new file mode 100644
index 00000000000..d43eff5ba4a
--- /dev/null
+++ b/lib/gitlab/themes.rb
@@ -0,0 +1,84 @@
+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 = 1
+
+    # Struct class representing a single Theme
+    Theme = Struct.new(:id, :name, :css_class)
+
+    # All available Themes
+    THEMES = [
+      Theme.new(1, 'Indigo', 'ui_indigo'),
+      Theme.new(2, 'Dark', 'ui_dark'),
+      Theme.new(3, 'Light', 'ui_light'),
+      Theme.new(4, 'Blue', 'ui_blue'),
+      Theme.new(5, 'Green', 'ui_green')
+    ].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
+      @default_id ||= begin
+        id = Gitlab.config.gitlab.default_theme.to_i
+        theme_ids = THEMES.map(&:id)
+
+        theme_ids.include?(id) ? id : APPLICATION_DEFAULT
+      end
+    end
+  end
+end