#!/usr/bin/env ruby
#
# Copyright (c) 2007 Daniel Rodríguez Troitiño
# 
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
# 
# Use:
# Invoke from the command line with file names as arguments. Each line will
# be the eDonkey link for one of the files. Share!

require 'openssl'

CHUNK_SIZE = 9728000

def ed2k_hash(file)
  file.rewind
  partial_hashes = Array.new
  while (chunk = file.read(CHUNK_SIZE)) do
    partial_hashes << OpenSSL::Digest::MD4.digest(chunk)
  end
  
  final_hash = if partial_hashes.size == 1
    partial_hashes[0]
  else
    OpenSSL::Digest::MD4.digest(partial_hashes.join(''))
  end
  
  final_hash.unpack('H*').join('')
end

def ed2k_link(filename)
  File.open(filename, 'rb') do |file|
    "ed2k://|file|#{File.basename(filename)}|#{File.size(filename)}|#{ed2k_hash(file)}|/"
  end
end

ARGV.each do |filename|
  puts ed2k_link(filename)
end