# NOTES: I just checked and Delegator does all its delegation through method missing, so 
# it probably makes sense to make this all one class, with method_missing doing the work.
# It might be faster, but harder, to pass a reference to the parent object and the way that
# the stub is accessed as a way to replace self with the actual object instead of stubbing.
# Not sure how that would work, but I am looking for something like self = something_else,
# which isn't kosher. 

module Aqua 
  class TempStub
    def initialize( method_hash ) 
      method_hash.each do |method_name, value|
        self.class.class_eval("
          def #{method_name}
            #{value.inspect}
          end  
        ")  
      end  
    end   
  end
  
  module StubDelegate 
    def __getobj__
      @_sd_obj          # return object we are delegating to
    end

    def __setobj__(obj)
      @_sd_obj = obj    # change delegation object
    end  
  end  
    
  class Stub < Delegator 
    include StubDelegate
    
    # Builds a new stub object which returns cached/stubbed methods until such a time as a non-cached method 
    # is requested.
    #
    # @param [Hash]
    # @option opts [Array] :methods A hash of method names and values
    # @option opts [String] :class The class of the object being stubbed
    # @option opts [String] :id The id of the object being stubbed
    #
    # @api semi-public
    def initialize( opts )
      meths = opts[:methods] || {}
      temp_stub = TempStub.new( meths )
      super( temp_stub )
      @_sd_obj = temp_stub
      self.delegate_class = opts[:class]
      self.delegate_id = opts[:id]
    end
    
    def method_missing( method, *args )
      if __getobj__.class.to_s != delegate_class.to_s
        load_delegate
        # resend! 
        if (args.size == 1 && !args.first.nil?) 
          __getobj__.send( method.to_sym, eval(args.map{|value| "'#{value}'"}.join(', ')) )
        else
          __getobj__.send( method.to_sym )
        end    
      else
        raise NoMethodError
      end
    end
    
      
    protected 
      attr_accessor :delegate_class, :delegate_id
      
      def load_delegate
        __setobj__( delegate_class.constantize.load( delegate_id ) )
      end   
    public
        
  end  

  class FileStub < Delegator 
    include StubDelegate
    
    # Builds a new stub object which returns cached/stubbed methods until such a time as a non-cached method 
    # is requested.
    #
    # @param [Hash]
    # @option opts [Array] :methods A hash of method names and values
    # @option opts [String] :class The class of the object being stubbed
    # @option opts [String] :id The id of the object being stubbed
    #
    # @api semi-public
    def initialize( opts )
      meths = opts[:methods] || {}
      temp_stub = TempStub.new( meths )
      super( temp_stub )
      @_sd_obj = temp_stub
      self.parent = opts[:parent]
      self.attachment_id = opts[:id]
    end
    
    def method_missing( method, *args )
      if load_attempt != true
        load_delegate 
        self.load_attempt = true
        # resend! 
        if (args.size == 1 && !args.first.nil?) 
          __getobj__.send( method.to_sym, eval(args.map{|value| "'#{value}'"}.join(', ')) )
        else
          __getobj__.send( method.to_sym )
        end
      else
        raise NoMethodError
      end
    end
    
      
    protected 
      attr_accessor :parent, :attachment_id, :load_attempt 
      
      def load_delegate
        __setobj__( parent.class::Storage.attachment( parent.id, attachment_id ) )
      end   
    public    
  end  
end