module React
  class TopLevelRailsComponent
    class << self
      attr_accessor :event_history

      def callback_history_for(proc_name)
        event_history[proc_name]
      end

      def last_callback_for(proc_name)
        event_history[proc_name].last
      end

      def clear_callback_history_for(proc_name)
        event_history[proc_name] = []
      end

      def event_history_for(event_name)
        event_history["_on#{event_name.event_camelize}"]
      end

      def last_event_for(event_name)
        event_history["_on#{event_name.event_camelize}"].last
      end

      def clear_event_history_for(event_name)
        event_history["_on#{event_name.event_camelize}"] = []
      end
    end

    def component
      return @component if @component
      paths_searched = []
      component = nil
      if params.component_name.start_with?('::')
        # if absolute path of component is given, look it up and fail if not found
        paths_searched << params.component_name
        component = begin
                      Object.const_get(params.component_name)
                    rescue NameError
                      nil
                    end
      else
        # if relative path is given, look it up like this
        # 1) we check each path + controller-name + component-name
        # 2) if we can't find it there we check each path + component-name
        # if we can't find it we just try const_get
        # so (assuming controller name is Home)
        # ::Foo::Bar will only resolve to some component named ::Foo::Bar
        # but Foo::Bar will check (in this order) ::Home::Foo::Bar, ::Components::Home::Foo::Bar, ::Foo::Bar, ::Components::Foo::Bar
        self.class.search_path.each do |scope|
          paths_searched << "#{scope.name}::#{params.controller}::#{params.component_name}"
          component = begin
                        scope.const_get(params.controller, false).const_get(params.component_name, false)
                      rescue NameError
                        nil
                      end
          break if component != nil
        end
        unless component
          self.class.search_path.each do |scope|
            paths_searched << "#{scope.name}::#{params.component_name}"
            component = begin
                          scope.const_get(params.component_name, false)
                        rescue NameError
                          nil
                        end
            break if component != nil
          end
        end
      end
      @component = component
      return @component if @component && @component.method_defined?(:render)
      raise "Could not find component class '#{params.component_name}' for params.controller '#{params.controller}' in any component directory. Tried [#{paths_searched.join(", ")}]"
    end

    before_mount do
      TopLevelRailsComponent.event_history = Hash.new { |h, k| h[k] = [] }
      @render_params = params.render_params
      component.validator.rules.each do |name, rules|
        next unless rules[:type] == Proc

        TopLevelRailsComponent.event_history[name] = []
        @render_params[name] = lambda do |*args|
          TopLevelRailsComponent.event_history[name] << args
        end
      end
    end

    def render
      React::RenderingContext.render(component, @render_params)
    end
  end
end