# Base Module for Rails 2 ViewModels.
#
module ViewModels
  
  # Base class from which all view_models inherit.
  #
  class Base
    
    # Make helper and helper_method available
    #
    include ActionController::Helpers
    
    # This is really only needed because some Rails helpers access
    # @controller directly.
    # It's really bad.
    #
    # TODO Make it call super.
    # 
    def initialize model, controller_or_view
      @model                 = model
      @context = @controller = ContextExtractor.new(controller_or_view).extract
    end
    
    class << self
      
      # Alias the context_method to the rails-centric controller_method.
      #
      alias controller_method context_method
      
      # Wrapper for add_template_helper in ActionController::Helpers, also
      # includes given helper in the view_model
      #
      # TODO extract into module
      #
      unless instance_methods.include?('old_add_template_helper')
        alias old_add_template_helper add_template_helper
        def add_template_helper helper_module
          include helper_module
          old_add_template_helper helper_module
        end
      end
      
      # Sets the view format and tries to render the given options.
      #
      # Note: Also caches [path, name, format] => template path.
      #
      def render renderer, options
        options.format! renderer
        path_store.cached options do
          options.file = template_path renderer, options
          renderer.render_with options
        end
      end
      
      protected
        
        # Accesses the view to find a suitable template path.
        #
        def template_path_from renderer, options
          template = renderer.find_template tentative_template_path(options)
          
          template && template.path
        end
        
    end # class << self
    
    # Delegate context methods.
    #
    context_method :form_authenticity_token, :protect_against_forgery?, :request_forgery_protection_token
    
    # Make all the dynamically generated routes (restful routes etc.)
    # available in the view_model
    #
    ActionController::Routing::Routes.install_helpers self
    
    protected
      
      alias controller context
      
      # CaptureHelper needs this.
      #
      attr_accessor :output_buffer
      
      # Returns a view instance for render_xxx.
      #
      # TODO Try getting a view instance from the controller.
      #
      def renderer
        # view = if controller.response.template
        #   controller.response.template
        # else
          View.new controller, master_helper_module
        # end
        
        # view.extend Extensions::View
      end
      
  end
end