#!/usr/bin/env ruby

require 'rubygems'
require 'rgl/adjacency'
require 'rgl/dot'
require 'osx/foundation'

class Singleton
  attr_accessor :members, :label
  
  def initialize(label, members=[])
    @members = members
    @label = label
  end
  
  def each_member
    @members.each do |member|
      yield member
    end
  end
end

class NIBContext
  CONNECTIONS_KEY = "com.apple.ibtool.document.connections"
  SINGLETON_LABEL_KEY = "source-label"
  MEMBER_LABEL_KEY = "destination-label"
  
  def initialize(hash)
    @singletons = {}
    hash[CONNECTIONS_KEY].each_value do |connection|
      key = connection[SINGLETON_LABEL_KEY].to_s
      @singletons[key] ||= Singleton.new(key)
      @singletons[key].members << connection[MEMBER_LABEL_KEY].to_s
    end
  end
  
  def get_graph
    return @composition_graph if @composition_graph
    @composition_graph = RGL::DirectedAdjacencyGraph.new

    @singletons.each_value do |singleton|
      singleton.each_member do |member|
        @composition_graph.add_edge member, singleton.label
      end
    end
    @composition_graph
  end
end


class Nib2DotGraph
  include OSX
  CONNECTIONS_FILE = File.join(ENV['TMPDIR'], "NIBConnections.plist")
  
	def usage(err_msg=nil)
		puts err_msg if err_msg
		puts "Usage: #{File.basename(__FILE__)} <NIB File> [file] [format]"
		exit 1
	end

	def run
	  if ARGV.size == 0
	    raise "NIB file must be provided."
	  elsif !File.exists?(ARGV[0])
	    raise "Could not find #{ARGV[0]} NIB"
	  end
	  
	  output_file = ARGV[1] || "graph"
	  format = ARGV[2] || "png"
	  
	  File.open(CONNECTIONS_FILE, "w") do |f|
      f.print(ibtool({:connections => nil}, ARGV[0]))
    end
    
    nib_context = NIBContext.new(NSDictionary.dictionaryWithContentsOfFile(CONNECTIONS_FILE))
    nib_context.get_graph.write_to_graphic_file(format, output_file)
    
    if %x|which dot|.empty?
      puts "Unable to write image #{File.basename(output_file)}.#{format} because 'dot' could not be found in $PATH (http://http://www.graphviz.org)"
      puts "Wrote #{File.basename(output_file)}.dot to #{File.dirname(output_file)}"
    else
      puts "Wrote #{File.basename(output_file)}.dot and #{File.basename(output_file)}.#{format} to #{File.dirname(output_file)}"
    end
	end

  private
  
  def ibtool(options={}, *args)
    command_options = options.map { |k,v| "--#{k} #{v}"}.join(" ")
    %x|ibtool #{command_options} #{args.join(" ")}|
  end
  
end

if $0 == __FILE__
	script = Nib2DotGraph.new
	begin
		script.run
	rescue Exception => e
		script.usage e.message
	end
end