module Lucid
  module AST
    class TDLWalker
      attr_accessor :configuration #:nodoc:
      attr_reader   :runtime #:nodoc:

      def initialize(runtime, listeners = [], configuration = Lucid::Configuration.default)
        @runtime, @listeners, @configuration = runtime, listeners, configuration
      end

      def execute(scenario, skip_hooks)
        runtime.with_hooks(scenario, skip_hooks) do
          scenario.skip_invoke! if scenario.failed?
          scenario.steps.accept(self)
        end
      end

      # The ability to visit specs is the first step in turning a spec into
      # what is traditionally called a feature. The spec file and the feature
      # are initially the same concept. When the spec is visited, the high
      # level construct (feature, ability) is determined.
      # @see Lucid::Runtime.run
      #def visit_features(features, &block)
      #  broadcast(features, &block)
      #end

      #def visit_feature(feature, &block)
      #  broadcast(feature, &block)
      #end

      #def visit_comment(comment, &block)
      #  broadcast(comment, &block)
      #end

      #def visit_comment_line(comment_line)
      #  broadcast(comment_line)
      #end

      #def visit_tags(tags, &block)
      #  broadcast(tags, &block)
      #end

      #def visit_tag_name(tag_name)
      #  broadcast(tag_name)
      #end

      #def visit_feature_name(keyword, name)
      #  broadcast(keyword, name)
      #end

      # Note that a feature_element refers to either a Scenario or
      # a ScenarioOutline.
      #def visit_feature_element(feature_element, &block)
      #  broadcast(feature_element, &block)
      #end

      #def visit_background(background, &block)
      #  broadcast(background, &block)
      #end

      #def visit_background_name(keyword, name, file_colon_line, source_indent)
      #  broadcast(keyword, name, file_colon_line, source_indent)
      #end

      #def visit_examples_array(examples_array, &block)
      #  broadcast(examples_array, &block)
      #end

      #def visit_examples(examples, &block)
      #  broadcast(examples, &block)
      #end

      #def visit_examples_name(keyword, name)
      #  broadcast(keyword, name)
      #end

      #def visit_outline_table(outline_table, &block)
      #  broadcast(outline_table, &block)
      #end

      #def visit_scenario_name(keyword, name, file_colon_line, source_indent)
      #  broadcast(keyword, name, file_colon_line, source_indent)
      #end

      #def visit_steps(steps, &block)
      #  broadcast(steps, &block)
      #end

      #def visit_step(step, &block)
      #  broadcast(step, &block)
      #end

      # This is being used to forward on messages from the AST to
      # the formatters. This is being done in lieu of the explicit
      # forwarding that was previously done.
      def method_missing(message, *args, &block)
        broadcast_message(message, *args, &block)
      end

      #def visit_step_result(keyword, step_match, multiline_arg, status, exception, source_indent, background, file_colon_line)
      #  broadcast(keyword, step_match, multiline_arg, status, exception, source_indent, background, file_colon_line) do
      #    visit_step_name(keyword, step_match, status, source_indent, background, file_colon_line)
      #    visit_multiline_arg(multiline_arg) if multiline_arg
      #    visit_exception(exception, status) if exception
      #  end
      #end

      def visit_step_result(step_result)
        broadcast(step_result) do
          step_result.accept(self)
        end
      end

      #def visit_step_name(keyword, step_match, status, source_indent, background, file_colon_line) #:nodoc:
      #  broadcast(keyword, step_match, status, source_indent, background, file_colon_line)
      #end

      def visit_multiline_arg(multiline_arg) #:nodoc:
        broadcast(multiline_arg) do
          multiline_arg.accept(self)
        end
      end

      #def visit_exception(exception, status) #:nodoc:
      #  broadcast(exception, status)
      #end

      #def visit_doc_string(string)
      #  broadcast(string)
      #end

      #def visit_table_row(table_row, &block)
      #  broadcast(table_row, &block)
      #end

      #def visit_table_cell(table_cell, &block)
      #  broadcast(table_cell, &block)
      #end

      #def visit_table_cell_value(value, status)
      #  broadcast(value, status)
      #end

      # Print +messages+. This method can be called from within StepDefinitions.
      def puts(*messages)
        broadcast(*messages)
      end

      # Embed +file+ of +mime_type+ in the formatter. This method can be called from within StepDefinitions.
      # For most formatters this is a no-op.
      def embed(file, mime_type, label)
        broadcast(file, mime_type, label)
      end

      private

      def broadcast(*args, &block)
        message = extract_method_name_from(caller[0])
        broadcast_message message, *args, &block
        self
      end

      def broadcast_message(message, *args, &block)
        message = message.to_s.gsub('visit_', '')
        if block_given?
          send_to_all("before_#{message}", *args)
          yield if block_given?
          send_to_all("after_#{message}", *args)
        else
          send_to_all(message, *args)
        end
        self
      end

      def send_to_all(message, *args)
        @listeners.each do |listener|
          if listener.respond_to?(message)
            listener.__send__(message, *args)
          end
        end
      end
      def extract_method_name_from(call_stack)
        #call_stack[0].match(/in `(.*)'/).captures[0]
        match = call_stack.match(/in `(.*)'/)
        match.captures[0]
      end

    end
  end
end