class ExecJS::DuktapeRuntime::Context

def call(identifier, *args)
  @ctx.exec_string("__execjs_duktape_call = #{identifier}", '(execjs)')
  @ctx.call_prop("__execjs_duktape_call", *args)
rescue Exception => e
  raise wrap_error(e)
end

def eval(source, options = {})
  return unless /\S/ =~ source
  @ctx.eval_string("(#{source.encode(Encoding::UTF_8)})", '(execjs)')
rescue Exception => e
  raise wrap_error(e)
end

def exec(source, options = {})
  return unless /\S/ =~ source
  @ctx.eval_string("(function(){#{source.encode(Encoding::UTF_8)}})()", '(execjs)')
rescue Exception => e
  raise wrap_error(e)
end

def initialize(runtime, source = "", options = {})
  @ctx = Duktape::Context.new(complex_object: nil)
  @ctx.exec_string(source.encode(Encoding::UTF_8), '(execjs)')
rescue Exception => e
  raise wrap_error(e)
end

def wrap_error(e)
  klass = case e
  when Duktape::SyntaxError
    RuntimeError
  when Duktape::Error
    ProgramError
  when Duktape::InternalError
    RuntimeError
  end
  if klass
    re = / \(line (\d+)\)$/
    lineno = e.message[re, 1] || 1
    error = klass.new(e.message.sub(re, ""))
    error.set_backtrace(["(execjs):#{lineno}"] + e.backtrace)
    error
  else
    e
  end
end