# frozen_string_literal: true

class ConfigDefault::Struct
  RESERVED_METHODS = %i[method_missing respond_to_missing? to_hash].freeze

  def initialize(attributes:, recursive: false, allow_nil: false)
    @attributes = ActiveSupport::HashWithIndifferentAccess.new(attributes)
    @allow_nil = allow_nil
    @recursive = recursive

    make_recursive!
    define_methods!

    @attributes.freeze
  end

  def [](key)
    @attributes[key]
  end

  def method_missing(method, *_args)
    return if @allow_nil
    raise StandardError.new("There is no option :#{method} in configuration.")
  end

  def respond_to_missing?(*_args)
    true
  end

  def to_hash
    dup = @attributes.dup

    if @recursive
      dup.each do |key, value|
        next unless value.is_a?(self.class)
        dup[key] = value.to_hash
      end
    end

    dup
  end

  private

  def make_recursive!
    return unless @recursive

    @attributes.each do |key, value|
      next unless value.is_a?(Hash)
      @attributes[key] = self.class.new(
        attributes: value,
        recursive: @recursive,
        allow_nil: @allow_nil,
      )
    end
  end

  def define_methods!
    @attributes.each do |key, value|
      next if RESERVED_METHODS.include?(key.to_sym)
      define_singleton_method(key) { value }
    end
  end
end