module Rhino
  
  class RubyObject < JS::ScriptableObject
    include JS::Wrapper

    # wrap an arbitrary (ruby) object
    def self.wrap(object)
      new(object)
    end
    
    def initialize(object)
      super()
      @ruby = object
    end

    # abstract Object Wrapper#unwrap();
    def unwrap
      @ruby
    end

    # abstract String Scriptable#getClassName();
    def getClassName
      @ruby.class.name
    end
    
    def toString
      "[ruby #{getClassName}]" # [object User]
    end

    # override Object Scriptable#get(String name, Scriptable start);
    # override Object Scriptable#get(int index, Scriptable start);
    def get(name, start)
      if name.is_a?(String)
        if @ruby.respond_to?(name)
          method = @ruby.method(name)
          if method.arity == 0 && # check if it is an attr_reader
            ( @ruby.respond_to?("#{name}=") || @ruby.instance_variables.include?("@#{name}") )
            begin
              return Rhino.to_javascript(method.call, self)
            rescue => e
              raise RubyFunction.wrap_error(e)
            end
          else
            return RubyFunction.new(@ruby.method(name))
          end
        end
      end
      super
    end

    # override boolean Scriptable#has(String name, Scriptable start);
    # override boolean Scriptable#has(int index, Scriptable start);
    def has(name, start)
      if name.is_a?(String) 
        if @ruby.respond_to?(name) || 
           @ruby.respond_to?("#{name}=") # might have a writer but no reader
          return true
        end
      end
      super
    end

    # override void Scriptable#put(String name, Scriptable start, Object value);
    # override void Scriptable#put(int index, Scriptable start, Object value);
    def put(name, start, value)
      if name.is_a?(String)
        if @ruby.respond_to?(set_name = "#{name}=")
          return @ruby.send(set_name, Rhino.to_ruby(value))
        end
      end
      super
    end
    
    # override Object[] Scriptable#getIds();
    def getIds
      ids = []
      @ruby.public_methods(false).each do |name| 
        name = name[0...-1] if name[-1, 1] == '=' # 'foo=' ... 'foo'
        name = name.to_java # java.lang.String
        ids << name unless ids.include?(name)
      end
      super.each { |id| ids.unshift(id) }
      ids.to_java
    end
    
    # protected Object ScriptableObject#equivalentValues(Object value)
    def equivalentValues(other) # JS == operator
      other.is_a?(RubyObject) && unwrap.eql?(other.unwrap)
    end
    
  end
  
  class RubyFunction < JS::BaseFunction
    
    # wrap a callable (Method/Proc)
    def self.wrap(callable)
      new(callable)
    end
    
    def self.wrap_error(e)
      JS::WrappedException.new(org.jruby.exceptions.RaiseException.new(e))
    end
    
    def initialize(callable)
      super()
      @callable = callable
    end
    
    def unwrap
      @callable
    end
    
    # protected Object ScriptableObject#equivalentValues(Object value)
    def equivalentValues(other) # JS == operator
      return false unless other.is_a?(RubyFunction)
      return true if unwrap == other.unwrap
      # Method.== does check if their bind to the same object
      # JS == means they might be bind to different objects :
      unwrap.to_s == other.unwrap.to_s # "#<Method: Foo#bar>"
    end
    
    # override Object ScriptableObject#getPrototype()
    def getPrototype
      unless proto = super
        #proto = ScriptableObject.getFunctionPrototype(getParentScope)
        #setPrototype(proto)
      end
      proto
    end
    
    # override Object BaseFunction#call(Context context, Scriptable scope, 
    #                                   Scriptable thisObj, Object[] args)
    def call(context, scope, this, args)
      rb_args = Rhino.args_to_ruby(args.to_a)
      begin
        result = @callable.call(*rb_args)
      rescue => e
        # ... correct wrapping thus it's try { } catch (e) works in JS :
        raise self.class.wrap_error(e)
      end
      Rhino.to_javascript(result, scope)
    end
    
  end
  
  class RubyConstructor < RubyFunction
    include JS::Wrapper
    
    # wrap a ruby class as as constructor function
    def self.wrap(klass)
      new(klass)
    end
    
    def initialize(klass)
      super(klass.method(:new))
      @klass = klass
    end
    
    def unwrap
      @klass
    end
    
    # override boolean Scriptable#hasInstance(Scriptable instance);
    def hasInstance(instance)
      return false unless instance
      return true if instance.is_a?(@klass)
      instance.is_a?(RubyObject) && instance.unwrap.is_a?(@klass)
    end
    
  end
  
end