module UnobtrusiveJavascript
  PLUGIN_NAME = 'unobtrusive_javascript'
  PLUGIN_PATH = "#{RAILS_ROOT}/vendor/plugins/#{PLUGIN_NAME}"
  PLUGIN_ASSET_PATH = "#{PLUGIN_PATH}/assets"
  PLUGIN_CONTROLLER_PATH = "#{PLUGIN_PATH}/lib/controllers"
  PLUGIN_VIEW_PATH = "#{PLUGIN_PATH}/lib/views"
  
  class Settings
    cattr_accessor :use_fake_script_links
    @@use_fake_script_links = false
  end
  
  def self.use_fake_script_links
    self::Settings.use_fake_script_links = true
    ActionController::Routing::Routes.add_route "/behaviours/event_selectors.js", :controller => "unobtrusive_javascript", :action => "event_selectors"
    ActionController::Routing::Routes.add_route "/behaviours/dynamic.js", :controller => "unobtrusive_javascript", :action => "generate"
  end
  
  module ControllerMethods
    def self.included(base)
      base.class_eval { before_filter :initialise_js_behaviours }
      base.class_eval { after_filter  :store_js_behaviours }
    end
    
    def register_js_behaviour(selector, behaviour)
      @js_behaviours = [] if @js_behaviours.nil?
      @js_behaviours << { :selector => selector, :js_behaviour => behaviour }
    end
    
    def initialise_js_behaviours
      @js_behaviours = []
    end
    
    def reset_js_behaviours
      session[:js_behaviours] = nil
    end

    def js_behaviours
      session[:js_behaviours]
    end

    def store_js_behaviours
      session[:js_behaviours] = @js_behaviours
    end
  end
  
  module Helpers
    def unobtrusive_javascript_files
      unless UnobtrusiveJavascript::Settings.use_fake_script_links
        output =  '<script type="text/javascript" src="/unobtrusive_javascript/event_selectors"></script>'
        output << '<script type="text/javascript" src="/unobtrusive_javascript/generate"></script>'
      else
        output =  javascript_include_tag("/behaviours/event_selectors")
        output << javascript_include_tag("/behaviours/dynamic")
      end
      output
    end
    
    def register_js_behaviour(selector, behaviour)
      @controller.register_js_behaviour(selector, behaviour)
    end
    
    def behaviour_blocks_for(rules)
      blocks = rules.collect { |rule| "\"#{rule[:selector]}\": function(element, event) {\n #{rule[:js_behaviour]} \n}"}
      blocks.join(",")
    end
  end
end