gem "shiftable"

class Captain < ActiveRecord::Base
  has_one :spaceship
end

class Spaceship < ActiveRecord::Base
  belongs_to :captain
end

class Captain < ActiveRecord::Base
  has_one :spaceship

  def sell_spaceship_to(nemesis_captain)
    Spaceship.shift_single(shift_to: nemesis_captain, shift_from: self)
  end
end

class Spaceship < ActiveRecord::Base
  belongs_to :captain
  extend Shiftable::Single.new belongs_to: :captain, has_one: :spaceship, precheck: true,
                               before_shift: ->(shifting_rel) { shifting_rel.result.ownership_changes += 1 }
end

class Spaceship < ActiveRecord::Base
  belongs_to :captain

  class << self
    include Shiftable::Single.new belongs_to: :captain, has_one: :spaceship, precheck: true,
                                  before_shift: lambda { |shifting:, shift_to:, shift_from:|
                                    shifting.ownership_changes += 1
                                  }
  end
end

class Spaceship < ActiveRecord::Base
  belongs_to :space_federation
  extend Shiftable::Collection.new belongs_to: :space_federation, has_many: :spaceships,
                                   before_shift: lambda { |shifting_rel|
                                     shifting_rel.each { |spaceship| spaceship.federation_changes += 1 }
                                   }
end

class SpaceFederation < ActiveRecord::Base
  has_many :spaceships

  def all_spaceships_commandeered_by(nemesis_federation)
    Spaceship.shift_cx(shift_to: nemesis_federation, shift_from: self)
  end
end

class SpaceTreaty < ActiveRecord::Base
  has_many :space_treaty_signature
end

class SpaceTreatySignature < ActiveRecord::Base
  belongs_to :space_treaty
  belongs_to :signatory, polymorphic: true
  # When two space federations assimilate (i.e. merge) to form a single larger federation,
  #   they become party to (i.e. signatories of) all the treaties that had been signed by either.
  # In practical terms, this means:
  #
  #   surviving_federation = SpaceFederation.find(1)
  #   assimilated_federation = SpaceFederation.find(2)
  #   SpaceTreatySignature.where(
  #     signatory_id: assimilated_federation_id,
  #     signatory_type: "SpaceFederation"
  #   ).update_all(
  #     signatory_id: surviving_federation.id
  #   )
  extend Shiftable::Collection.new(
    belongs_to: :signatory, has_many: :space_treaty_signature,
    polymorphic: { type: "SpaceFederation", as: :signatory },
    method_prefix: "space_federation_",
    before_shift: lambda { |shifting_rel|
      # Each item in shifting_rel is an instance of the class where Shiftable::Collection is defined,
      #   in this case: SpaceTreatySignature
      # And each of them has a signatory which is of type "SpaceFederation",
      #   because a polymorphic collection only targets one type.
      # shifting_rel.each { |signature| signature.signatory == "SpaceFederation" }
    }
  )
end

class SpaceFederation < ActiveRecord::Base
  has_many :space_treaty_signature, as: :signatory
  has_many :space_treaties, through: :space_treaty_signatures, as: :signatory
  has_many :treaty_planets, class_name: "Planet", through: :space_treaty_signatures, as: :signatory
  has_many :treaty_stations, class_name: "SpaceStation", through: :space_treaty_signatures, as: :signatory
  def assimilate_from(other_federation)
    SpaceTreatySignature.space_federation_shift_pcx(shift_to: self, shift_from: other_federation)
  end
end

# Including Planet and SpaceStation, for completeness of the example as the other "types" of polymorphic signatories
class Planet < ActiveRecord::Base
  has_many :space_treaty_signature, as: :signatory
  has_many :space_treaties, through: :space_treaty_signatures
  has_many :treaty_federations, class_name: "SpaceFederation", through: :space_treaty_signatures, as: :signatory
  has_many :treaty_stations, class_name: "SpaceStation", through: :space_treaty_signatures, as: :signatory
end

class SpaceStation < ActiveRecord::Base
  has_many :space_treaty_signature, as: :signatory
  has_many :space_treaties, through: :space_treaty_signatures
  has_many :treaty_federations, class_name: "SpaceFederation", through: :space_treaty_signatures, as: :signatory
  has_many :treaty_planets, class_name: "Planet", through: :space_treaty_signatures, as: :signatory
end

class Spaceship < ActiveRecord::Base
  belongs_to :space_federation
  extend Shiftable::Collection.new(
    belongs_to: :space_federation,
    has_many: :spaceships,
    before_shift: lambda { |shifting_rel|
                    shifting_rel.each { |spaceship| spaceship.federation_changes += 1 }
                  },
    wrapper: {
      each: lambda { |rel, record, &block|
              tresult = record.transaction_wrapper(outside_rescued_errors: ActiveRecord::RecordNotUnique) do
                puts "melon #{record.name} honey #{rel.count}"
                block.call # does the actual saving!
              end
              # NOTE: The value returned by the wrapper will also be returned by the call to `shift_cx`.
              #       You could return the whole tresult object here, instead of just true/false!
              tresult.success?
            },
      all: lambda { |rel, &block|
             tresult = Spaceship.transaction_wrapper do
               puts "can you eat #{rel.count} shoes"
               block.call
             end
             tresult.success?
           }
    }
  )
end

class SpaceFederation < ActiveRecord::Base
  has_many :spaceships

  def all_spaceships_commandeered_by(nemesis_federation)
    Spaceship.shift_cx(shift_to: nemesis_federation, shift_from: self)
  end
end

class Captain < ActiveRecord::Base
  has_one :spaceship

  def sell_spaceship_to(nemesis_captain)
    Spaceship.shift_single(shift_to: nemesis_captain, shift_from: self)
  end
end

class Spaceship < ActiveRecord::Base
  belongs_to :captain
  extend Shiftable::Single.new belongs_to: :captain, has_one: :spaceship, precheck: true,
                               before_shift: ->(shifting_rel) { shifting_rel.result.ownership_changes += 1 }

  belongs_to :space_federation
  extend Shiftable::Collection.new(
    belongs_to: :space_federation,
    has_many: :spaceships,
    before_shift: lambda { |shifting_rel|
      shifting_rel.each { |spaceship| spaceship.federation_changes += 1 }
    },
    wrapper: {
      each: lambda { |rel, record, &block|
              tresult = record.transaction_wrapper(outside_rescued_errors: ActiveRecord::RecordNotUnique) do
                puts "melon #{record.name} honey #{rel.count}"
                block.call # does the actual saving!
              end
              tresult.success?
            },
      all: lambda { |rel, &block|
             tresult = Spaceship.transaction_wrapper do
               puts "can you eat #{rel.count} shoes"
               block.call
             end
             tresult.success?
           }
    }
  )
end

class SpaceFederation < ActiveRecord::Base
  has_many :captains
  has_many :spaceships
  has_many :space_treaty_signature, as: :signatory
  has_many :space_treaties, through: :space_treaty_signatures, as: :signatory
  has_many :treaty_planets, class_name: "Planet", through: :space_treaty_signatures, as: :signatory
  has_many :treaty_stations, class_name: "SpaceStation", through: :space_treaty_signatures, as: :signatory

  def assimilate_from(other_federation)
    SpaceTreatySignature.space_federation_shift_cx(shift_to: self, shift_from: other_federation)
  end

  def all_spaceships_commandeered_by(nemesis_federation)
    Spaceship.shift_cx(shift_to: nemesis_federation, shift_from: self)
  end
end
class SpaceTreaty < ActiveRecord::Base
  has_many :space_treaty_signatures
end

class SpaceTreatySignature < ActiveRecord::Base
  belongs_to :space_treaty
  belongs_to :signatory, polymorphic: true
  extend Shiftable::Collection.new(
    belongs_to: :signatory, has_many: :space_treaty_signatures,
    polymorphic: { type: "SpaceFederation", as: :signatory },
    method_prefix: "space_federation_"
  )
end

# Including Planet and SpaceStation, for completeness of the example as the other "types" of polymorphic signatories
class Planet < ActiveRecord::Base
  has_many :space_treaty_signatures, as: :signatory
  has_many :space_treaties, through: :space_treaty_signatures
  has_many :treaty_federations, class_name: "SpaceFederation", through: :space_treaty_signatures, as: :signatory
  has_many :treaty_stations, class_name: "SpaceStation", through: :space_treaty_signatures, as: :signatory
end

class SpaceStation < ActiveRecord::Base
  has_many :space_treaty_signature, as: :signatory
  has_many :space_treaties, through: :space_treaty_signatures
  has_many :treaty_federations, class_name: "SpaceFederation", through: :space_treaty_signatures, as: :signatory
  has_many :treaty_planets, class_name: "Planet", through: :space_treaty_signatures, as: :signatory
end

spec.add_dependency "shiftable", "~> 0.7"