class AssemblyInfoEngine
  ENGINES = {
    "F#" => lambda { FSharpEngine.new },
    "C#" => lambda { CSharpEngine.new },
    "C++.Net" => lambda { CppCliEngine.new },
    "VB.Net" => lambda { VbNetEngine.new }
  }
  
  DEFAULT = ENGINES["C#"]

  def self.from_language(language)
    (ENGINES[language] || DEFAULT).call
  end

  def build_attribute(attr_name, attr_data)
    attribute = "#{@start_token}assembly: #{attr_name}("
    
    if attr_data != nil
      if attr_data.is_a? Hash
        # Only named parameters
        attribute << build_named_parameters(attr_data)
      elsif attr_data.is_a? Array
        if attr_data.last.is_a? Hash
          # Positional and named parameters
          attribute << build_positional_parameters(attr_data.slice(0, attr_data.length - 1))
          attribute << ", "
          attribute << build_named_parameters(attr_data.last)
        else
          # Only positional parameters
          attribute << build_positional_parameters(attr_data)
        end
      else
        # Single positional parameter
        attribute << "#{attr_data.inspect}"
      end
    end
    
    attribute << ")#{@end_token}"
  end
  
  def build_named_parameters(data)
    params = []
    data.each_pair { |k, v| params << "#{k.to_s} #{@assignment} #{v.inspect}" }
    params.join(", ")
  end
  
  def build_positional_parameters(data)
    data.flatten.map{ |a| a.inspect }.join(", ")
  end

  def build_using_statement(namespace)
    "#{@using} #{namespace}#{@statement_terminator}"
  end
end