module Vool
  class ClassMethodExpression < Expression
    attr_reader :name, :args , :body

    def initialize( name , args , body )
      @name , @args , @body = name , args , body
      raise "no bod" unless @body
    end

    def to_mom(clazz)
      raise "not singleton" unless clazz.class == Parfait::SingletonClass
      raise( "no class in #{self}") unless clazz
      method = clazz.add_instance_method_for(name , make_arg_type , make_frame , body )
      #puts "CLass method Class:#{clazz}:#{name}"
      compiler = method.compiler_for(clazz.instance_type)
      each {|node| raise "Blocks not implemented" if node.is_a?(LambdaExpression)}
      compiler
    end

    def each(&block)
      block.call(self)
      @body.each(&block)
    end

    def make_arg_type(  )
      type_hash = {}
      @args.each {|arg| type_hash[arg] = :Object }
      Parfait::Type.for_hash( type_hash )
    end

    def to_s(depth = 0)
      arg_str = @args.collect{|a| a.to_s}.join(', ')
      at_depth(depth , "def self.#{name}(#{arg_str})\n#{@body.to_s(depth + 1)}end")
    end

    private

    def make_frame
      nodes = []
      @body.each { |node| nodes << node }
      type_hash = {}
      nodes.each do |node|
        next unless node.is_a?(LocalVariable) or node.is_a?(LocalAssignment)
        type_hash[node.name] = :Object
      end
      Parfait::Type.for_hash( type_hash )
    end

  end
end