module JsonbAccessor::Macro::ClassMethods

def jsonb_accessor(jsonb_attribute, field_types)
  field_names = field_types.keys
  names_and_store_keys = field_types.each_with_object({}) do |(name, type), mapping|
    _type, options = Array(type)
    mapping[name.to_s] = (options.try(:delete, :store_key) || name).to_s
  end
  # Defines virtual attributes for each jsonb field.
  field_types.each do |name, type|
    attribute name, *type
  end
  # Setters are in a module to allow users to override them and still be able to use `super`.
  setters = Module.new do
    # Overrides the setter created by `attribute` above to make sure the jsonb attribute is kept in sync.
    names_and_store_keys.each do |name, store_key|
      define_method("#{name}=") do |value|
        super(value)
        new_values = (public_send(jsonb_attribute) || {}).merge(store_key => public_send(name))
        write_attribute(jsonb_attribute, new_values)
      end
    end
    # Overrides the jsonb attribute setter to make sure the jsonb fields are kept in sync.
    define_method("#{jsonb_attribute}=") do |value|
      indifferent_value = value.try(:with_indifferent_access) || {}
      value_with_store_keys = names_and_store_keys.each_with_object({}) do |(name, store_key), new_value|
        new_value[store_key] = indifferent_value[name]
      end
      super(value_with_store_keys)
      new_attributes = field_names.each_with_object({}) { |name, defaults| defaults[name] = nil }.merge(value || {})
      new_attributes.each { |name, new_value| write_attribute(name, new_value) }
    end
  end
  include setters
  # Makes sure new objects have the appropriate values in their jsonb fields.
  after_initialize do
    jsonb_values = public_send(jsonb_attribute) || {}
    jsonb_values.each do |store_key, value|
      name = names_and_store_keys.key(store_key)
      write_attribute(name, value) if name
    end
    clear_changes_information if persisted?
  end
  # <jsonb_attribute>_where scope
  scope("#{jsonb_attribute}_where", lambda do |attributes|
    store_key_attributes = attributes.each_with_object({}) do |(name, value), new_attributes|
      store_key = names_and_store_keys[name.to_s]
      new_attributes[store_key] = value
    end
    jsonb_where(jsonb_attribute, store_key_attributes)
  end)
end