discourse/app/models/admin_dashboard_next_data.rb

class AdminDashboardNextData
  include StatsCacheable

  GLOBAL_REPORTS ||= [
    'signups',
    'topics',
    'trending_search',
    'new_contributors'
  ]

  USER_REPORTS ||= [
    'users_by_trust_level',
    'users_by_type'
  ]

  def initialize(opts = {})
    @opts = opts
  end

  def self.fetch_stats
    AdminDashboardNextData.new.as_json
  end

  def self.stats_cache_key
    'dash-next-stats'
  end

  def as_json(_options = nil)
    @json ||= {
      global_reports: AdminDashboardNextData.reports(GLOBAL_REPORTS),
      user_reports: AdminDashboardNextData.reports(USER_REPORTS),
      last_backup_taken_at: last_backup_taken_at,
      updated_at: Time.zone.now.as_json
    }
  end

  def last_backup_taken_at
    if last_backup = Backup.all.last
      File.ctime(last_backup.path).utc
    end
  end

  def self.reports(source)
    source.map { |type| Report.find(type).as_json }
  end
end