# frozen_string_literal: true

module EE
  module Gitlab
    module Auth
      module LDAP
        module Sync
          class Users
            attr_reader :provider, :proxy

            def self.execute(proxy)
              self.new(proxy).update_permissions
            end

            def initialize(proxy)
              @provider = proxy.provider
              @proxy = proxy
            end

            # rubocop: disable CodeReuse/ActiveRecord
            def update_permissions
              dns = member_dns
              return true if dns.empty?

              current_users_with_attribute = ::User.with_provider(provider).where(attribute => true)
              verified_users_with_attribute = []

              # Verify existing users and add new ones.
              dns.each do |member_dn|
                user = update_user_by_dn(member_dn)
                verified_users_with_attribute << user if user
              end

              # Revoke the unverified users.
              (current_users_with_attribute - verified_users_with_attribute).each do |user|
                user[attribute] = false
                user.save
              end

              true
            rescue ::Gitlab::Auth::LDAP::LDAPConnectionError
              Rails.logger.warn("Error syncing #{attribute} users for provider '#{provider}'. LDAP connection Error")

              false
            end
            # rubocop: enable CodeReuse/ActiveRecord

            private

            def attribute
              raise NotImplementedError
            end

            def member_dns
              raise NotImplementedError
            end

            def update_user_by_dn(member_dn)
              user = ::Gitlab::Auth::LDAP::User.find_by_uid_and_provider(member_dn, provider)

              if user.present?
                user[attribute] = true
                user.save

                user
              else
                Rails.logger.debug do
                  <<-MSG.strip_heredoc.tr("\n", ' ')
                    #{self.class.name}: User with DN `#{member_dn}` should be marked as
                    #{attribute} but there is no user in GitLab with that identity.
                    Membership will be updated once the user signs in for the first time.
                  MSG
                end

                nil
              end
            end
          end
        end
      end
    end
  end
end
