1 files changed, 92 insertions, 0 deletions
diff --git a/lib/banzai/reference_parser/user_parser.rb b/lib/banzai/reference_parser/user_parser.rb
new file mode 100644
index 00000000000..a12b0d19560
--- /dev/null
+++ b/lib/banzai/reference_parser/user_parser.rb
@@ -0,0 +1,92 @@
+module Banzai
+  module ReferenceParser
+    class UserParser < BaseParser
+      self.reference_type = :user
+
+      def referenced_by(nodes)
+        group_ids = []
+        user_ids = []
+        project_ids = []
+
+        nodes.each do |node|
+          if node.has_attribute?('data-group')
+            group_ids << node.attr('data-group').to_i
+          elsif node.has_attribute?(self.class.data_attribute)
+            user_ids << node.attr(self.class.data_attribute).to_i
+          elsif node.has_attribute?('data-project')
+            project_ids << node.attr('data-project').to_i
+          end
+        end
+
+        find_users_for_groups(group_ids) | find_users(user_ids) |
+          find_users_for_projects(project_ids)
+      end
+
+      def nodes_visible_to_user(user, nodes)
+        group_attr = 'data-group'
+        groups = lazy { grouped_objects_for_nodes(nodes, Group, group_attr) }
+        visible = []
+        remaining = []
+
+        nodes.each do |node|
+          if node.has_attribute?(group_attr)
+            node_group = groups[node.attr(group_attr).to_i]
+
+            if node_group &&
+              can?(user, :read_group, node_group)
+              visible << node
+            end
+          # Remaining nodes will be processed by the parent class'
+          # implementation of this method.
+          else
+            remaining << node
+          end
+        end
+
+        visible + super(current_user, remaining)
+      end
+
+      def nodes_user_can_reference(current_user, nodes)
+        project_attr = 'data-project'
+        author_attr = 'data-author'
+
+        projects = lazy { projects_for_nodes(nodes) }
+        users = lazy { grouped_objects_for_nodes(nodes, User, author_attr) }
+
+        nodes.select do |node|
+          project_id = node.attr(project_attr)
+          user_id = node.attr(author_attr)
+
+          if project && project_id && project.id == project_id.to_i
+            true
+          elsif project_id && user_id
+            project = projects[project_id.to_i]
+            user = users[user_id.to_i]
+
+            project && user ? project.team.member?(user) : false
+          else
+            true
+          end
+        end
+      end
+
+      def find_users(ids)
+        return [] if ids.empty?
+
+        User.where(id: ids).to_a
+      end
+
+      def find_users_for_groups(ids)
+        return [] if ids.empty?
+
+        User.joins(:group_members).where(members: { source_id: ids }).to_a
+      end
+
+      def find_users_for_projects(ids)
+        return [] if ids.empty?
+
+        Project.where(id: ids).flat_map { |p| p.team.members.to_a }
+      end
+    end
+  end
+end