# from http://www.jayfields.com/src/dslcontext.txt

script = <<-eos
    if the '$5-$10 Limit' list is more than 12 then notify the floor to open
    if the '$1-$2 No Limit' list is more than 15 then notify the floor to open
    if the '$5-$10 Limit' list is more than 8 then notify the brush to announce
    if the '$1-$2 No Limit' list is more than 10 then notify the brush to announce
eos

class Broadcast
  def self.notify(stakes, options)
    puts DslContext.sym_to_stakes(stakes)
    options.each_pair do |name, value|
      puts "  #{name} #{value}"
    end
  end
end

class List
  def self.size_for(stakes)
    20
  end
end

class DslContext
  def self.execute(text)
    rules = polish_text(text)
    rules.each do |rule|
      result = self.new.instance_eval(rule)
      yield result if block_given?
    end
  end

  def self.bubble(*methods)
    methods.each do |method|
      define_method(method) { |args| args }
    end
  end

  def self.polish_text(text)
    rules = text.split("\n")
    rules.collect do |rule|
      rule.gsub!(/'.+'/,extract_stakes(rule))
      rule << " end"
    end
  end

  def self.extract_stakes(rule)
    stakes = rule.scan(/'.+'/).first
    stakes.delete!("'").gsub!('$','dollar').gsub!('-','dash').gsub!(' ','space')
  end

  def self.sym_to_stakes(sym)
    sym.to_s.gsub!('dollar','$').gsub!('dash','-').gsub!('space',' ')
  end
end

class ContextOne < DslContext

  bubble :than, :is, :list, :the, :to

  def more(value)
    '> ' + value.to_s
  end

  def method_missing(sym, *args)
    @stakes = sym
    eval "List.size_for(sym) #{args.first}"
  end

  def floor(value)
    __position(value, :floor)
  end

  def brush(value)
    __position(value, :brush)
  end

  def open
    __action(:open)
  end

  def announce
    __action(:announce)
  end

  def __action(to)
    { :action => to }
  end

  def __position(value, title)
    value[:position] = title
    value
  end

  def notify(value)
    [@stakes, value]
  end

end

class ContextTwo < DslContext

  bubble :than, :is, :list, :the, :to, :more, :notify, :floor, :open, :brush

  def announce
    @stakes
  end

  alias open announce

  def method_missing(sym, *args)
    @stakes = sym
  end

end

class ContextThree < DslContext

  bubble :than, :is, :list, :the, :to, :more, :notify, :announce, :open, :open

  def announce; end
  def open; end

  def brush(value)
    :brush
  end

  def floor(value)
    :floor
  end

  def method_missing(sym, *args)
    true
  end

end

module Kernel
  def silence_warnings

        # multiple assignment
    old_verbose, $VERBOSE = $VERBOSE, nil
    yield
  ensure
    $VERBOSE = old_verbose
  end
end

silence_warnings do
  puts "\nContext One:"
  ContextOne.execute(script) do |notification|
    Broadcast.notify(*notification)
  end

  puts "\nContext Two:"
  ContextTwo.execute(script) do |stakes|
    puts ContextTwo.sym_to_stakes(stakes)
  end

  puts "\nContext Three"
  ContextThree.execute(script) do |positions|
    puts positions
  end
end