#!/usr/bin/env ruby
#
# Proof of concept FOAF "knows" contact list Bloom filter. danbri@danbri.org

require 'rubygems'
gem 'bloomfilter'
require 'bloomfilter/BloomFilter'



# also needed: gem install RubyInline

# this version uses the gem packaged successor to BloominSimple


require 'json'

# we pass in a hasher block
# http://blog.rapleaf.com/dev/?p=6
bf = BloomFilter.new(1000) do |item| Digest::SHA1.digest(item.downcase.strip).unpack("VVVV") end


#see also http://ajax.suaccess.org/ruby/ruby-on-rails-converting-between-numeric-bases/
#http://www.faqs.org/rfcs/rfc2045.html
# perl: http://perldoc.perl.org/functions/pack.html
#    b	A bit string (ascending bit order inside each byte, like vec()).
#http://safari.oreilly.com/9780596529864/array_pack_directives
#http://www.rubycentral.com/pickaxe/ref_c_array.html#Array.pack
puts "############"

js = `roqet -q bloomer.rq -r json`; # get contact list as prop/value pairs
res = JSON.parse js
res["results"]["bindings"].each do |contact|
    prop = contact['prop']['value']
    val = contact['val']['value']
     print "Adding: '#{prop} #{val}' ; "
    bf.add("#{prop} #{val}")
    puts
end

puts                bf.include?("http://xmlns.com/foaf/0.1/mbox mailto:d.m.steer@lse.ac.uk")     # => true
puts                bf.include?("http://xmlns.com/foaf/0.1/mbox mailto:santaclaus@npole.example.com")    # => false
puts                bf.include?("http://xmlns.com/foaf/0.1/openid http://santa.example.com/")    # => false



require 'Base64'

class BloomFilter

  def to_web
    Base64.encode64("#{@bits.size} #{@bits.to_s}")
  end

  def guts
    puts "Serializing: "
    i=0
    asc=""
    while(i< @bits.size) 
      i +=1 
      v = @bits[i]? 1 : 0 
      asc += v.to_s
    end
    return asc
  end
end

puts bf.to_web