1 files changed, 49 insertions, 0 deletions
diff --git a/app/finders/joined_groups_finder.rb b/app/finders/joined_groups_finder.rb
new file mode 100644
index 00000000000..e7523136fea
--- /dev/null
+++ b/app/finders/joined_groups_finder.rb
@@ -0,0 +1,49 @@
+# Class for finding the groups a user is a member of.
+class JoinedGroupsFinder
+  def initialize(user = nil)
+    @user = user
+  end
+
+  # Finds the groups of the source user, optionally limited to those visible to
+  # the current user.
+  #
+  # current_user - If given the groups of "@user" will only include the groups
+  #                "current_user" can also see.
+  #
+  # Returns an ActiveRecord::Relation.
+  def execute(current_user = nil)
+    if current_user
+      relation = groups_visible_to_user(current_user)
+    else
+      relation = public_groups
+    end
+
+    relation.order_id_desc
+  end
+
+  private
+
+  # Returns the groups the user in "current_user" can see.
+  #
+  # This list includes all public/internal projects as well as the projects of
+  # "@user" that "current_user" also has access to.
+  def groups_visible_to_user(current_user)
+    base  = @user.authorized_groups.visible_to_user(current_user)
+    extra = public_and_internal_groups
+    union = Gitlab::SQL::Union.new([base.select(:id), extra.select(:id)])
+
+    Group.where("namespaces.id IN (#{union.to_sql})")
+  end
+
+  def public_groups
+    groups_for_projects(@user.authorized_projects.public_only)
+  end
+
+  def public_and_internal_groups
+    groups_for_projects(@user.authorized_projects.public_and_internal_only)
+  end
+
+  def groups_for_projects(projects)
+    @user.groups.public_and_given_groups(projects.select(:namespace_id))
+  end
+end