module Nitro

# Scaffolding is one facet of Nitro's Rapid Application 
# Develpoment (RAD) features. The scaffolder automatically 
# generates common code for managed object and their 
# controllers.

module Scaffold

  # Automatically enchant all models ?
  
  setting :enchant_all_models, :default => true, :doc => 'Automatically enchant all models?'

  # 'Enchant' a model class (typically a managed class, 
  # entity). A collection of useful methods are magically 
  # added to the class and/or the class instances.
  #
  # * to_s
  # * to_href
  # * to_link
  # * to_edit_href
  # * to_admin_href
  #--
  # to_xxx is used instead of xxx in an attempt to avoid 
  # colisions with user defined methods.
  #++
  
  def self.model(*classes)
    for c in classes
      enchant_model c
    end
  end
  
  #--
  # Actually enchant the given class. Override this method
  # to customize for your application. The string calculation
  # code is deliberatly dynamic to work with Ruby's OO 
  # features.
  #++
  
  def self.enchant_model(klass)
    # Find the controller that handles this model. Unless no
    # controller annotation is defined, try to find a controller
    # of the form: Model::Controller. Some examples:
    #
    # class Ticket
    #   ann self, :controller => SpecialTicketController
    #   ..
    # end
    #
    # or try to find a Ticket::Controller class. 

    controller = klass.ann.self[:controller] || klass.constant('Controller')

    # If the class defines a text_key use it to create more
    # readable (and SEO friendly) urls.
    
    key = klass.ann.self[:text_key] || 'oid' 

    # to_s
          
    if klass.instance_methods.include? 'title'
      define_instance_method klass, :to_s, %{ title }, force = true      
    elsif klass.instance_methods.include? 'name'
      define_instance_method klass, :to_s, %{ name }, force = true      
    end
  
    # to_href
    # ex: /articles/23

    define_instance_method klass, :to_href, %{
      "\#{#{controller}.mount_path}/read/\#{#{key}}".squeeze('/')
    }

    # to_link
    # ex: <a href="/articles/23">The article's title</a>
    
    define_instance_method klass, :to_link, %{
      %|<a href="\#{to_href}">\#{to_s}</a>|
    }

    # to_link
    # ex: <a href="/articles/23">The article's title</a>
    
    define_class_method klass, :controller, %{
      #{controller}
    }
                  
    if defined? OgSystemController
      self.extend(OgSystemHelper)

      # to_edit_href
      # ex: admin/update/Article/23

      define_instance_method klass, :to_edit_href, %{
        "\#{OgSystemController.mount_path}/update/#{class_to_name(klass)}/\#{oid}"
      }

      # to_admin_href
      # ex: admin/list/Article

      define_instance_method klass, :to_admin_href, %{
        "\#{AdminController.mount_path}/list/#{class_to_name(klass)}"
      }
                    
      # to_admin_href
      # ex: admin/list/Article

      define_class_method klass, :to_admin_href, %{
        "\#{AdminController.mount_path}/list/#{class_to_name(klass)}"
      }
    end
  end


  #--
  # This helper defines an instance method for the 
  # scaffolded class. The method is only defined if the klass
  # does not already respond to it.
  #++
  
  def self.define_instance_method(klass, meth, body, force = false)
    if force or (!klass.instance_methods.include? meth.to_s)
      klass.module_eval %{
        def #{meth}
          #{body}
        end
      }
    end
  end

  #--
  # This helper defines an class method for the 
  # scaffolded class. The method is only defined if the klass
  # does not already respond to it.
  #++
  
  def self.define_class_method(klass, meth, body, force = false)
    if force or (!klass.respond_to? meth.to_s)
      klass.module_eval %{
        def self.#{meth}
          #{body}
        end
      }
    end
  end
    
end

end