namespace :katello do
  desc "Clean duplicate installed packages"
  task :clean_installed_packages => :environment do
    User.current = User.anonymous_admin

    puts "Populating cache"
    cache = PackageCache.new
    cache.populate

    puts "Cleaning katello_host_installed_packages table.."
    cleaning_start = Time.now
    total = ::Host.count
    count = 1
    ::Host.find_each do |host|
      puts "Host #{count}/#{total} #{host.name}"

      if host.installed_package_ids.any?
        nvras = host.installed_packages.pluck(:nvra)
        ids = nvras.map { |nvra| cache.fetch(nvra) }
        existing_ids = host.installed_package_ids.to_a
        unless existing_ids.sort == ids.sort
          host.sync_package_associations(ids)
        end
      end
      count += 1
    end

    cleaning_total = sprintf('%.2f', Time.now - cleaning_start)
    puts "katello_host_installed_packages table has been cleaned, total time was #{cleaning_total} seconds."
    puts "Removing records from katello_installed_packages that are no longer referenced..."
    cleaning_start = Time.now

    existing = Katello::HostInstalledPackage.select(:installed_package_id).uniq.pluck(:installed_package_id)

    batch = 20_000
    until Katello::InstalledPackage.where('id not in (?)', existing).limit(1).count == 0
      begin
        deleted = Katello::InstalledPackage.where('id not in (?)', existing).where("id < #{batch}").delete_all
        sleep(3) if deleted > 0
        puts "Inspected #{batch} records in katello_host_installed_packages to remove unreferenced entries in katello_installed_packages.."
      rescue ActiveRecord::InvalidForeignKey
        puts "Some records in batch #{batch} were unable to be removed. This is usually due to system registrations or updates that occurred after the script started."
        puts "The script will now exit. Usually, simply re-running the script is sufficient to work through this issue."
        raise
      end
      batch += 20_000
    end
    cleaning_total = sprintf('%.2f', Time.now - cleaning_start)
    puts "katello_installed_packages table has been cleaned to remove unreferenced entries, total time was #{cleaning_total} seconds."

    puts "Script is complete, setting installed package search to updated method. To disable this, set 'bulk query installed packages' to 'false' in Katello settings."
    Setting[:bulk_query_installed_packages] = true
    puts "Done!"
  end

  class PackageCache
    def initialize
      @cache = {}
    end

    def populate
      Katello::InstalledPackage.select("nvra, MIN(id) as id").group("nvra").each do |pkg|
        @cache[pkg.nvra] = pkg.id
      end
    end

    def fetch(nvra)
      @cache[nvra] ||= Katello::InstalledPackage.where(:nvra => nvra).first.id
    end
  end
end