class BuildMethodBase
  def self.call(required_keywords: [], optional_keywords: [], method_name: :call)
    new(
      required_keywords: required_keywords,
      optional_keywords: optional_keywords,
      method_name:       method_name
    ).call
  end

  def initialize(required_keywords: [], optional_keywords: [], method_name: :call)
    @required_keywords = required_keywords
    @optional_keywords = optional_keywords
    @method_name       = method_name
  end

  def call
    parts.compact.join "\n"
  end

  private

  attr_reader :required_keywords, :optional_keywords, :method_name

  def parts
    [declaration, body, 'end']
  end

  def declaration
    raise NotImplementedError
  end

  def body
    raise NotImplementedError
  end

  def all_keywords
    required_keywords + optional_keywords
  end

  def required_keyword_segments
    required_keywords.map { |keyword| "#{keyword}:" }
  end

  def optional_keyword_segments
    optional_keywords.map { |keyword| "#{keyword}: nil" }
  end

  def declaration_keyword_arguments
    return if all_keywords.empty?
    (required_keyword_segments + optional_keyword_segments).join(', ')
  end
end