sanger/sequencescape

# frozen_string_literal: true

# Include in assets that can act as sources/destinations for transfers
module Transfer::Associations
  def self.included(base) # rubocop:todo Metrics/AbcSize, Metrics/MethodLength
    base.class_eval do
      include Transfer::State

      has_many :transfers_as_source, # rubocop:todo Rails/HasManyOrHasOneDependent
               -> { order(created_at: :asc) },
               class_name: 'Transfer',
               foreign_key: :source_id,
               inverse_of: :source

      has_many :transfers_to_tubes, # rubocop:todo Rails/HasManyOrHasOneDependent
               -> { order(created_at: :asc) },
               class_name: 'Transfer::BetweenPlateAndTubes',
               foreign_key: :source_id,
               inverse_of: :source

      has_many :transfers_as_destination, # rubocop:todo Rails/HasManyOrHasOneDependent
               -> { order(id: :asc) },
               class_name: 'Transfer',
               foreign_key: :destination_id,
               inverse_of: :destination

      # This looks odd but it's a LEFT OUTER JOIN, meaning that the rows we would be interested in have no source_id.
      scope :with_no_outgoing_transfers,
            lambda {
              select("DISTINCT #{base.quoted_table_name}.*")
                .joins(
                  # rubocop:todo Layout/LineLength
                  "LEFT OUTER JOIN `transfers` outgoing_transfers ON outgoing_transfers.`source_id`=#{base.quoted_table_name}.`id`"
                  # rubocop:enable Layout/LineLength
                )
                .where('outgoing_transfers.source_id IS NULL')
            }
    end
  end
end