class Opal::Nodes::IterNode

def args
  if Fixnum === args_sexp or args_sexp.nil?
    s(:array)
  elsif args_sexp.type == :lasgn
    s(:array, args_sexp)
  else
    args_sexp[1]
  end
end

def args_to_params(sexp)
  result = []
  sexp.each do |arg|
    if arg[0] == :lasgn
      ref = variable(arg[1])
      scope.add_arg ref
      result << ref
    elsif arg[0] == :array
      result << scope.next_temp
    else
      raise "Bad js_block_arg: #{arg[0]}"
    end
  end
  result
end

def body
  compiler.returns(body_sexp || s(:nil))
end

def compile
  opt_args  = extract_opt_args
  block_arg = extract_block_arg
  # find any splat args
  if args.last.is_a?(Sexp) and args.last.type == :splat
    splat = args.last[1][1]
    args.pop
    len = args.length
  end
  params = args_to_params(args[1..-1])
  params << splat if splat
  to_vars = identity = body_code = nil
  in_scope do
    identity = scope.identify!
    add_temp "self = #{identity}.$$s || this"
    compile_args(args[1..-1], opt_args, params)
    if splat
      scope.add_arg splat
      push "#{splat} = $slice.call(arguments, #{len - 1});"
    end
    if block_arg
      scope.block_name = block_arg
      scope.add_temp block_arg
      scope_name = scope.identify!
      line "#{block_arg} = #{scope_name}.$$p || nil, #{scope_name}.$$p = null;"
    end
    body_code = stmt(body)
    to_vars = scope.to_vars
  end
  line body_code
  unshift to_vars
  unshift "(#{identity} = function(#{params.join ', '}){"
  push "}, #{identity}.$$s = self, #{identity})"
end

def compile_args(args, opt_args, params)
  args.each_with_index do |arg, idx|
    if arg.type == :lasgn
      arg = variable(arg[1])
      if opt_args and current_opt = opt_args.find { |s| s[1] == arg.to_sym }
        push "if (#{arg} == null) #{arg} = ", expr(current_opt[2]), ";"
      else
        push "if (#{arg} == null) #{arg} = nil;"
      end
    elsif arg.type == :array
      arg[1..-1].each_with_index do |_arg, _idx|
        _arg = variable(_arg[1])
        push "#{_arg} = #{params[idx]}[#{_idx}];"
      end
    else
      raise "Bad block arg type"
    end
  end
end

def extract_block_arg
  if args.last.is_a?(Sexp) and args.last.type == :block_pass
    block_arg = args.pop
    block_arg = block_arg[1][1].to_sym
  end
end

def extract_opt_args
  if args.last.is_a?(Sexp) and args.last.type == :block
    opt_args = args.pop
    opt_args.shift
    opt_args
  end
end