require 'ae'

module QED

  # Scope is the context in which QED documents are run.
  #
  class Scope < Module
 
    #
    def self.new(applique)
      @applique = applique
      super(applique)
    end

    #
    def self.const_missing(name)
      @applique.const_get(name)
    end

    #
    def initialize(applique)
      super()
      @applique = applique
      extend self
      extend applique # TODO: extend or include applique or none ?
      #extend DSLi
      create_clean_binding_method
    end

    # This turned out to be the key to proper scoping.
    def create_clean_binding_method
      define_method(:__binding__) do
        @__binding__ ||= binding
      end
    end

    #module DSLi

      #def initialize
      #  @__binding__ = binding
      #end

      #def __binding__
      #  @__binding__
      #end

      #
      #def __binding__
      #  @__binding__ ||= binding
      #end

      #
      def eval(code)
        super(code, __binding__)
      end

      #
      def When(*patterns, &procedure)
        @applique.When(*patterns, &procedure)
      end

      #
      def Before(type=:code, &procedure)
        @applique.Before(type, &procedure)
      end

      #
      def After(type=:code, &procedure)
        @applique.After(type, &procedure)
      end

      # Table-based steps.
      #--
      # TODO: Look for files relative to script first?
      #++
      def Table(file=nil, &blk)
        file = file || @_tables.last
        tbl = YAML.load(File.new(file))
        tbl.each do |set|
          blk.call(*set)
        end
        @__tables__ ||= []
        @__tables__ << file
      end

      # Read/Write a static data fixture.
      #--
      # TODO: Perhaps #Data would be best as some sort of Kernel extension.
      #
      # TODO: Look for files relative to script first?
      #++
      def Data(file, &content)
        raise if File.directory?(file)
        if content
          FileUtils.mkdir_p(File.dirname(fname))
          case File.extname(file)
          when '.yml', '.yaml'
            File.open(file, 'w'){ |f| f << content.call.to_yaml }
          else
            File.open(file, 'w'){ |f| f << content.call }
          end
        else
          #raise LoadError, "no such fixture file -- #{fname}" unless File.exist?(fname)
          case File.extname(file)
          when '.yml', '.yaml'
            YAML.load(File.new(file))
          else
            File.read(file)
          end
        end
      end

    #end#module DSL

  end#class Scope

end#module QED