class ActiveFedora::Associations::Builder::Association

def self.add_destroy_callbacks(model, reflection)
  name = reflection.name
  model.before_destroy lambda do |o|
    a = o.association(name)
    a.handle_dependency if a.respond_to? :handle_dependency
  end
end

def self.build(model, name, options, &block)
  if model.dangerous_attribute_method?(name)
    Deprecation.warn(ActiveFedora::Base, "You tried to define an association named #{name} on the model #{model.name}, but " \
                         "this will conflict with a method #{name} already defined by ActiveFedora. " \
                         "Please choose a different association name.")
  end
  extension = define_extensions model, name, &block
  reflection = create_reflection model, name, nil, options, extension
  define_accessors(model, reflection)
  define_callbacks(model, reflection)
  define_validations model, reflection
  reflection
end

def self.check_dependent_options(dependent)
  unless valid_dependent_options.include? dependent
    raise ArgumentError, "The :dependent option must be one of #{valid_dependent_options}, but is :#{dependent}"
  end
end

def self.create_reflection(model, name, _scope, options, _extension = nil)
  unless name.is_a?(Symbol)
    name = name.to_sym
    Deprecation.warn(ActiveFedora::Base, "association names must be a Symbol")
  end
  validate_options(options)
  new(model, name, options).build
end

def self.define_accessors(model, reflection)
  mixin = model.generated_association_methods
  name = reflection.name
  define_readers(mixin, name)
  define_writers(mixin, name)
end

def self.define_callbacks(model, reflection)
  if dependent = reflection.options[:dependent]
    check_dependent_options(dependent)
    add_destroy_callbacks(model, reflection)
  end
  Association.extensions.each do |extension|
    extension.build model, reflection
  end
end

def self.define_extensions(_model, _name)
end

def self.define_readers(mixin, name)
  mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
    def #{name}(*args)
      association(:#{name}).reader(*args)
    end
  CODE
end

def self.define_validations(_model, _reflection)
  # noop
end

def self.define_writers(mixin, name)
  mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
    def #{name}=(value)
      association(:#{name}).writer(value)
    end
  CODE
end

def self.macro
  raise NotImplementedError
end

def self.valid_dependent_options
  raise NotImplementedError
end

def self.valid_options(_options)
  VALID_OPTIONS + Association.extensions.flat_map(&:valid_options)
end

def self.validate_options(options)
  options.assert_valid_keys(valid_options(options))
end

def build
  configure_dependency if options[:dependent] # see https://github.com/rails/rails/commit/9da52a5e55cc665a539afb45783f84d9f3607282
  model.create_reflection(self.class.macro, name, options, model)
end

def configure_dependency
  return unless options[:dependent]
  return if model.association(name).respond_to? :handle_dependency
  unless [:destroy, :delete].include?(options[:dependent])
    raise ArgumentError, "The :dependent option expects either :destroy or :delete (#{options[:dependent].inspect})"
  end
  method_name = "belongs_to_dependent_#{options[:dependent]}_for_#{name}"
  model.send(:class_eval, <<-eoruby, __FILE__, __LINE__ + 1)
    def #{method_name}
      association = #{name}
      association.#{options[:dependent]} if association
    end
  eoruby
  model.after_destroy method_name
end

def initialize(model, name, options)
  @model = model
  @name = name
  @options = options
  translate_property_to_predicate
  validate_options
end

def predicate(property)
  return property if property.is_a? RDF::URI
  ActiveFedora::Predicates.find_graph_predicate(property)
end

def translate_property_to_predicate
  return unless options[:property]
  Deprecation.warn Association, "the :property option to `#{model}.#{macro} :#{name}' is deprecated and will be removed in active-fedora 10.0. Use :predicate instead", caller(5)
  options[:predicate] = predicate(options.delete(:property))
end

def validate_options
  self.class.validate_options(options)
end