module Ci
  class Stage < ActiveRecord::Base
    extend Ci::Model
    include Importable
    include HasStatus
    include Gitlab::OptimisticLocking

    enumerate_status!

    belongs_to :project
    belongs_to :pipeline

    has_many :commit_statuses, foreign_key: :stage_id
    has_many :builds, foreign_key: :stage_id

    validates :project, presence: true, unless: :importing?
    validates :pipeline, presence: true, unless: :importing?
    validates :name, presence: true, unless: :importing?

    ## TODO, should we extract these events to `Ci::Eventable`?
    #
    state_machine :status, initial: :created do
      event :enqueue do
        transition created: :pending
        transition [:success, :failed, :canceled, :skipped] => :running
      end

      event :run do
        transition any - [:running] => :running
      end

      event :skip do
        transition any - [:skipped] => :skipped
      end

      event :drop do
        transition any - [:failed] => :failed
      end

      event :succeed do
        transition any - [:success] => :success
      end

      event :cancel do
        transition any - [:canceled] => :canceled
      end

      event :block do
        transition any - [:manual] => :manual
      end
    end

    def update!
      retry_optimistic_lock(self) do
        case commit_statuses.latest.status
        when 'pending' then enqueue
        when 'running' then run
        when 'success' then succeed
        when 'failed' then drop
        when 'canceled' then cancel
        when 'manual' then block
        when 'skipped' then skip
        else skip
        end
      end
    end
  end
end