#!/usr/bin/ruby

require 'nntplib'
require 'hpricot'
require 'thread'
require 'optparse'

nthreads = 4
nntpserver = 'news.free.fr'
subdir = '.'
cont = false
OptionParser.new { |opts|
	opts.on('-s', '--server host', 'news server') { |o| nntpserver = o }
	opts.on('-n', '--nthreads N', 'number of parallel connections') { |o| nthreads = o.to_i }
	opts.on('-d', '--downloaddir dir', 'where to put downloaded files') { |o| subdir = o }
	opts.on('-c', '--continue', 'do not redl existing files') { |o| cont = true }
	opts.on('-v', '--verbose', 'show nntp raw messages') { $VERBOSE = true }
}.parse!

nzb = Hpricot(File.open(ARGV.shift))

Dir.mkdir subdir unless File.directory? subdir
Dir.chdir subdir

group = (nzb/:group).first.innerHTML
artids = []
(nzb/:file).each { |file|
	next if cont and Dir['?????*'].any? { |fn| file.attributes['subject'].include? fn }
	artids.concat((file/:segment).map { |seg| seg.innerHTML })
}

m = Mutex.new

Array.new(nthreads) {
	Thread.new(artids, m) { |artids, m|
		s = NntpClient.new nntpserver, group
		begin
			while id = m.synchronize { artids.shift }
				$stderr.print "#{artids.length}    \r" if $stderr.isatty
				s.dl_bin "<#{id}>"
			end
		ensure
			p s.quit if s.sock
		end
	}
}.each { |t| t.join }

system 'parrar-sh', '.'