class V8::Portal::Proxies

def empty?
  js_empty? && rb_empty?
end

def initialize
  @js_proxies_rb2js = {}
  @js_proxies_js2rb = {}
  @rb_proxies_rb2js = {}
  @rb_proxies_js2rb = {}
  @clear_js_proxy = ClearJSProxy.new(@js_proxies_rb2js, @js_proxies_js2rb)
  @clear_rb_proxy = ClearRubyProxy.new(@rb_proxies_rb2js, @rb_proxies_js2rb)
end

def js2rb(js)
  if rb = js_proxy_2_rb_object(js)
    return rb
  elsif rb = js_object_2_rb_proxy(js)
    return rb
  else
    proxy = block_given? ? yield(js) : Object.new
    register_ruby_proxy proxy, :for => js if proxy && js && js.kind_of?(V8::C::Handle)
    return proxy
  end
end

def js_empty?
  @js_proxies_rb2js.empty? && @js_proxies_js2rb.empty?
end

def js_object_2_rb_proxy(object)
  if id = @rb_proxies_js2rb[object]
    ObjectSpace._id2ref id
  end
rescue RangeError
  # sometimes, the Ruby proxy has been garbage collected, but
  # the finalizer which runs has not been called. That's OK
  # we just clear out the entry, and return nil so that a new
  # proxy can be created.
  @clear_rb_proxy.call(id)
  return nil
end

def js_proxy_2_rb_object(proxy)
  @js_proxies_js2rb[proxy]
end

def rb2js(rb)
  if js = rb_proxy_2_js_object(rb)
    return js
  elsif js = rb_object_2_js_proxy(rb)
    return js
  else
    proxy = block_given? ? yield(rb) : V8::C::Object::New()
    register_javascript_proxy proxy, :for => rb unless @js_proxies_rb2js[rb]
    return proxy
  end
end

def rb_empty?
  @rb_proxies_rb2js.empty? && @rb_proxies_js2rb.empty?
end

def rb_object_2_js_proxy(object)
  @js_proxies_rb2js[object]
end

def rb_proxy_2_js_object(proxy)
  @rb_proxies_rb2js[proxy.object_id]
end

def register_javascript_proxy(proxy, options = {})
  target = options[:for] or fail ArgumentError, "must specify the object that you're proxying with the :for => param"
  fail ArgumentError, "javascript proxy must be a V8::C::Handle, not #{proxy.class}" unless proxy.kind_of?(V8::C::Handle)
  fail DoubleProxyError, "target already has a registered proxy" if @js_proxies_rb2js[target]
  @js_proxies_js2rb[proxy] = target
  @js_proxies_rb2js[target] = proxy
  proxy.MakeWeak(nil, @clear_js_proxy)
end

def register_ruby_proxy(proxy, options = {})
  target = options[:for] or fail ArgumentError, "must specify the object that you're proxying with the :for => param"
  fail ArgumentError, "'#{proxy.inspect}' is not a Handle to an actual V8 object" unless target.kind_of?(V8::C::Handle)
  @rb_proxies_rb2js[proxy.object_id] = target
  @rb_proxies_js2rb[target] = proxy.object_id
  ObjectSpace.define_finalizer(proxy, @clear_rb_proxy)
end