require 'yaml'
require 'rubygems'
require 'twitter'

class Hash
  def except(*keys)
    self.reject { |k,v| keys.include?(k) }
  end
end

screen_name = ARGV[0]
user        = YAML.load(File.read("#{screen_name}.yml"))
people      = YAML.load(File.read("#{screen_name}-people.yml"))
friends     = YAML.load(File.read("#{screen_name}-friends.yml"))
friend_map  = YAML.load(File.read("#{screen_name}-friend_map.yml"))
recommend   = 10

# do a pairwise intersection for the list of friends of each of our friends
intersect_counts = Hash.new(0)
friend_map.each_pair do |id, friend_ids|
  friend_map.except(id).each_pair do |compare_id, compare_friend_ids|
    (friend_map[id] & friend_map[compare_id]).each {|i| intersect_counts[i] += 1}
  end
end

friend_ids = friends.collect {|f| f.id}
# show how many of the top 10 in this metric you're already following
count = intersect_counts.except(user.id).sort {|a, b| b[1] <=> a[1]}.slice(0, recommend).inject(0) do |r, f|
  friend_ids.include?(f.first) ? r : r + 1
end
puts "#{screen_name} is following #{count} of the top #{recommend} recommendations"

# now show 10 that you should be following

# take out the people we're already friends with and ourself
new_intersects = intersect_counts.except(*friend_ids).except(user.id)

# sort them and output the top 10 new friends
puts "Top #{recommend} of the #{people.except(*friend_ids).except(user.id).size} possible new friends for #{screen_name}"
new_intersects.sort {|a, b| b[1] <=> a[1]}.slice(0, recommend).each do |f|
  puts "#{people[f.first].name} (#{people[f.first].screen_name}) is followed by #{f.last / 2} pairs"
end