Isolate User and Project models for mentions migrations

Isolate User and Project models used to fetch & parse respective
user mentions.

lib/gitlab/background_migration/user_mentions/lib/banzai/reference_parser/isolated_mentioned_project_parser.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    module UserMentions
+      module Lib
+        module Banzai
+          module ReferenceParser
+            # isolated Banzai::ReferenceParser::MentionedGroupParser
+            class IsolatedMentionedProjectParser < ::Banzai::ReferenceParser::MentionedProjectParser
+              extend ::Gitlab::Utils::Override
+
+              self.reference_type = :user
+
+              override :references_relation
+              def references_relation
+                ::Gitlab::BackgroundMigration::UserMentions::Models::Project
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/background_migration/user_mentions/lib/banzai/reference_parser/isolated_mentioned_user_parser.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    module UserMentions
+      module Lib
+        module Banzai
+          module ReferenceParser
+            # isolated Banzai::ReferenceParser::MentionedGroupParser
+            class IsolatedMentionedUserParser < ::Banzai::ReferenceParser::MentionedUserParser
+              extend ::Gitlab::Utils::Override
+
+              self.reference_type = :user
+
+              override :references_relation
+              def references_relation
+                ::Gitlab::BackgroundMigration::UserMentions::Models::User
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/background_migration/user_mentions/lib/gitlab/isolated_reference_extractor.rb

@@ -7,7 +7,7 @@ module Gitlab
         module Gitlab
           # Extract possible GFM references from an arbitrary String for further processing.
           class IsolatedReferenceExtractor < ::Gitlab::ReferenceExtractor
-            REFERABLES = %i(isolated_mentioned_group).freeze
+            REFERABLES = %i(isolated_mentioned_group isolated_mentioned_user isolated_mentioned_project).freeze
 
             REFERABLES.each do |type|
               define_method("#{type}s") do

lib/gitlab/background_migration/user_mentions/lib/gitlab/isolated_visibility_level.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    module UserMentions
+      module Lib
+        module Gitlab
+          # Gitlab::IsolatedVisibilityLevel module
+          #
+          # Define allowed public modes that can be used for
+          # GitLab projects to determine project public mode
+          #
+          module IsolatedVisibilityLevel
+            extend ::ActiveSupport::Concern
+
+            included do
+              scope :public_to_user, -> (user = nil) do
+                where(visibility_level: IsolatedVisibilityLevel.levels_for_user(user))
+              end
+            end
+
+            PRIVATE  = 0 unless const_defined?(:PRIVATE)
+            INTERNAL = 10 unless const_defined?(:INTERNAL)
+            PUBLIC   = 20 unless const_defined?(:PUBLIC)
+
+            class << self
+              def levels_for_user(user = nil)
+                return [PUBLIC] unless user
+
+                if user.can_read_all_resources?
+                  [PRIVATE, INTERNAL, PUBLIC]
+                elsif user.external?
+                  [PUBLIC]
+                else
+                  [INTERNAL, PUBLIC]
+                end
+              end
+            end
+
+            def private?
+              visibility_level_value == PRIVATE
+            end
+
+            def internal?
+              visibility_level_value == INTERNAL
+            end
+
+            def public?
+              visibility_level_value == PUBLIC
+            end
+
+            def visibility_level_value
+              self[visibility_level_field]
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/background_migration/user_mentions/models/commit_user_mention.rb

@@ -7,6 +7,7 @@ module Gitlab
       module Models
         class CommitUserMention < ActiveRecord::Base
           self.table_name = 'commit_user_mentions'
+          self.inheritance_column = :_type_disabled
 
           def self.resource_foreign_key
             :commit_id

lib/gitlab/background_migration/user_mentions/models/concerns/isolated_feature_gate.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    module UserMentions
+      module Models
+        module Concerns
+          # isolated FeatureGate module
+          module IsolatedFeatureGate
+            def flipper_id
+              return if new_record?
+
+              "#{self.class.name}:#{id}"
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/background_migration/user_mentions/models/concerns/isolated_mentionable.rb

@@ -70,8 +70,8 @@ module Gitlab
             def build_mention_values(resource_foreign_key)
               refs = all_references(author)
 
-              mentioned_users_ids = array_to_sql(refs.mentioned_users.pluck(:id))
-              mentioned_projects_ids = array_to_sql(refs.mentioned_projects.pluck(:id))
+              mentioned_users_ids = array_to_sql(refs.isolated_mentioned_users.pluck(:id))
+              mentioned_projects_ids = array_to_sql(refs.isolated_mentioned_projects.pluck(:id))
               mentioned_groups_ids = array_to_sql(refs.isolated_mentioned_groups.pluck(:id))
 
               return if mentioned_users_ids.blank? && mentioned_projects_ids.blank? && mentioned_groups_ids.blank?

lib/gitlab/background_migration/user_mentions/models/concerns/namespace/recursive_traversal.rb

@@ -6,7 +6,7 @@ module Gitlab
       module Models
         module Concerns
           module Namespace
-            # extracted methods for recursive traversing of namespace hierarchy
+            # isolate recursive traversal code for namespace hierarchy
             module RecursiveTraversal
               extend ActiveSupport::Concern
 

lib/gitlab/background_migration/user_mentions/models/design_management/design.rb

@@ -10,6 +10,9 @@ module Gitlab
             include EachBatch
             include Concerns::MentionableMigrationMethods
 
+            self.table_name = 'design_management_designs'
+            self.inheritance_column = :_type_disabled
+
             def self.user_mention_model
               Gitlab::BackgroundMigration::UserMentions::Models::DesignUserMention
             end

lib/gitlab/background_migration/user_mentions/models/design_user_mention.rb

@@ -7,6 +7,7 @@ module Gitlab
       module Models
         class DesignUserMention < ActiveRecord::Base
           self.table_name = 'design_user_mentions'
+          self.inheritance_column = :_type_disabled
 
           def self.resource_foreign_key
             :design_id

lib/gitlab/background_migration/user_mentions/models/epic.rb

@@ -17,10 +17,10 @@ module Gitlab
           cache_markdown_field :description, issuable_state_filter_enabled: true
 
           self.table_name = 'epics'
+          self.inheritance_column = :_type_disabled
 
-          belongs_to :author, class_name: "User"
-          belongs_to :project
-          belongs_to :group
+          belongs_to :author, class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::User"
+          belongs_to :group, class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::Group"
 
           def self.user_mention_model
             Gitlab::BackgroundMigration::UserMentions::Models::EpicUserMention

lib/gitlab/background_migration/user_mentions/models/epic_user_mention.rb

@@ -7,6 +7,7 @@ module Gitlab
       module Models
         class EpicUserMention < ActiveRecord::Base
           self.table_name = 'epic_user_mentions'
+          self.inheritance_column = :_type_disabled
 
           def self.resource_foreign_key
             :epic_id

lib/gitlab/background_migration/user_mentions/models/group.rb

@@ -7,6 +7,8 @@ module Gitlab
         # isolated Group model
         class Group < ::Gitlab::BackgroundMigration::UserMentions::Models::Namespace
           self.store_full_sti_class = false
+          self.inheritance_column = :_type_disabled
+
           has_one :saml_provider
 
           def self.declarative_policy_class

lib/gitlab/background_migration/user_mentions/models/merge_request.rb

@@ -17,10 +17,11 @@ module Gitlab
           cache_markdown_field :description, issuable_state_filter_enabled: true
 
           self.table_name = 'merge_requests'
+          self.inheritance_column = :_type_disabled
 
-          belongs_to :author, class_name: "User"
-          belongs_to :target_project, class_name: "Project"
-          belongs_to :source_project, class_name: "Project"
+          belongs_to :author, class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::User"
+          belongs_to :target_project, class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::Project"
+          belongs_to :source_project, class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::Project"
 
           alias_attribute :project, :target_project
 

lib/gitlab/background_migration/user_mentions/models/merge_request_user_mention.rb

@@ -7,6 +7,7 @@ module Gitlab
       module Models
         class MergeRequestUserMention < ActiveRecord::Base
           self.table_name = 'merge_request_user_mentions'
+          self.inheritance_column = :_type_disabled
 
           def self.resource_foreign_key
             :merge_request_id

lib/gitlab/background_migration/user_mentions/models/namespace.rb

@@ -5,9 +5,11 @@ module Gitlab
     module UserMentions
       module Models
         # isolated Namespace model
-        class Namespace < ApplicationRecord
-          include FeatureGate
-          include ::Gitlab::VisibilityLevel
+        class Namespace < ActiveRecord::Base
+          self.inheritance_column = :_type_disabled
+
+          include Concerns::IsolatedFeatureGate
+          include Gitlab::BackgroundMigration::UserMentions::Lib::Gitlab::IsolatedVisibilityLevel
           include ::Gitlab::Utils::StrongMemoize
           include Gitlab::BackgroundMigration::UserMentions::Models::Concerns::Namespace::RecursiveTraversal
 

lib/gitlab/background_migration/user_mentions/models/note.rb

@@ -16,9 +16,9 @@ module Gitlab
           attr_mentionable :note, pipeline: :note
           cache_markdown_field :note, pipeline: :note, issuable_state_filter_enabled: true
 
-          belongs_to :author, class_name: "User"
+          belongs_to :author, class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::User"
           belongs_to :noteable, polymorphic: true
-          belongs_to :project
+          belongs_to :project, class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::Project"
 
           def for_personal_snippet?
             noteable && noteable.class.name == 'PersonalSnippet'

lib/gitlab/background_migration/user_mentions/models/project.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    module UserMentions
+      module Models
+        # isolated Namespace model
+        class Project < ActiveRecord::Base
+          include Concerns::IsolatedFeatureGate
+          include Gitlab::BackgroundMigration::UserMentions::Lib::Gitlab::IsolatedVisibilityLevel
+
+          self.table_name = 'projects'
+          self.inheritance_column = :_type_disabled
+
+          belongs_to :group, -> { where(type: 'Group') }, foreign_key: 'namespace_id', class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::Group"
+          belongs_to :namespace, class_name: "::Gitlab::BackgroundMigration::UserMentions::Models::Namespace"
+          alias_method :parent, :namespace
+
+          # Returns a collection of projects that is either public or visible to the
+          # logged in user.
+          def self.public_or_visible_to_user(user = nil, min_access_level = nil)
+            min_access_level = nil if user&.can_read_all_resources?
+
+            return public_to_user unless user
+
+            if user.is_a?(::Gitlab::BackgroundMigration::UserMentions::Models::User)
+              where('EXISTS (?) OR projects.visibility_level IN (?)',
+                    user.authorizations_for_projects(min_access_level: min_access_level),
+                    levels_for_user(user))
+            end
+          end
+
+          def grafana_integration
+            nil
+          end
+
+          def default_issues_tracker?
+            true # we do not care of the issue tracker type(internal or external) when parsing mentions
+          end
+
+          def visibility_level_field
+            :visibility_level
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/background_migration/user_mentions/models/user.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    module UserMentions
+      module Models
+        # isolated Namespace model
+        class User < ActiveRecord::Base
+          include Concerns::IsolatedFeatureGate
+
+          self.table_name = 'users'
+          self.inheritance_column = :_type_disabled
+
+          has_many :project_authorizations, dependent: :delete_all # rubocop:disable Cop/ActiveRecordDependent
+
+          def authorizations_for_projects(min_access_level: nil, related_project_column: 'projects.id')
+            authorizations = project_authorizations
+                               .select(1)
+                               .where("project_authorizations.project_id = #{related_project_column}")
+
+            return authorizations unless min_access_level.present?
+
+            authorizations.where('project_authorizations.access_level >= ?', min_access_level)
+          end
+
+          def can_read_all_resources?
+            can?(:read_all_resources)
+          end
+
+          def can?(action, subject = :global)
+            Ability.allowed?(self, action, subject)
+          end
+        end
+      end
+    end
+  end
+end