module Lutaml::Model::ComparableModel

def self.included(base)
  base.extend(ClassMethods)
end

def already_compared?(other, compared_objects)
  compared_objects[comparison_key(other)]
end

def attributes_hash(processed_objects)
  self.class.attributes.map do |attr, _|
    attr_value = send(attr)
    if attr_value.respond_to?(:calculate_hash)
      attr_value.calculate_hash(processed_objects)
    else
      attr_value.hash
    end
  end
end

def calculate_hash(processed_objects = {}.compare_by_identity)
  return if processed_objects.key?(self)
  processed_objects[self] = true
  ([self.class] + attributes_hash(processed_objects)).hash
end

def comparison_key(other)
  "#{object_id}:#{other.object_id}"
end

def eql?(other, compared_objects = {})
  return true if equal?(other)
  return false unless same_class?(other)
  return true if already_compared?(other, compared_objects)
  compared_objects[comparison_key(other)] = true
  self.class.attributes.all? do |attr, _|
    attr_value = send(attr)
    other_value = other.send(attr)
    if attr_value.respond_to?(:eql?) && same_class?(attr_value)
      attr_value.eql?(other_value, compared_objects)
    else
      attr_value == other_value
    end
  end
end

def hash
  calculate_hash
end

def same_class?(other)
  other.instance_of?(self.class)
end