#!/usr/bin/ruby

$: << File.expand_path('~/dev/nntp')

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

nthreads = 4
$nntpserver = 'news.free.fr'
subdir = '.'
xover = true
do_dl = true
cont = false
startid = 0
startidpc = nil
$noydec = 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('-v', '--verbose', 'show nntp raw messages') { $VERBOSE = true }
	opts.on('-x', '--xpat', 'use xpat (faster, but innacurate)') { xover = false }
	opts.on('-c', '--continue', 'do not redl existing files') { cont = true }
	opts.on('-r', '--nodecode', 'download files without ydecoding') { $noydec = true }
	opts.on('-i', '--startid N', 'start xpat/xover from it') { |o| (o[-1] == ?%) ? (startidpc = o.to_i) : (startid = o.to_i) }
	opts.on('--show', 'do not download') { do_dl = false }
}.parse!
raise 'group needed' unless group = ARGV.shift
pattern = ARGV.shift

Dir.mkdir subdir if not File.directory? subdir
Dir.chdir subdir

def start_dler(group, m, list, lister)
	Thread.new {
		s = NntpClient.new $nntpserver, group
		begin
			loop do
				while id = m.synchronize { list.shift }
					$stderr.print "#{list.length}    \r" if $stderr.isatty
					if $noydec
						File.open("nntpgot.#{id}", 'w') { |fd|
							s.article(id) { |l| fd.puts l }
						}
					else
						s.dl_bin id, m
					end
				end
				break if list.empty? and not lister.alive?
				sleep 1
			end
		ensure
			p s.quit if s.sock
		end
	}
end

m = Mutex.new
list = []

lister = Thread.new {
	s = NntpClient.new $nntpserver, group
	begin
		if xover
			if startidpc
				foo, bar, min, max, baz = s.group(group).split.map { |i| i.to_i }
				startid = min + (max - min) * startidpc / 100
			end
			s.xover("#{startid}-") { |l|
				id, subj = l.split("\t", 2)
				puts "#{id} #{subj.split("\t")[0]}" if id[-4..-1] == '0000' and $VERBOSE
				if subj =~ /#{pattern}/i
					subj = subj.split("\t", 2).first
					next if cont and Dir['?????*'].any? { |fn| subj.include? fn }
					puts "#{id} #{subj}" if subj =~ /\s\(0*1\/\d+\)/
					m.synchronize { list << id.to_i }
				end
			}
			puts 'xover done'
		else
			s.xpat('subject', "#{startid}-", pattern) { |l|
				id, subj = l.split(' ', 2)
				next if cont and Dir.entries('.').any? { |fn| subj.include? fn }
				puts subj
				m.synchronize { list << id.to_i }
			}
			puts 'xpat done'
		end
	ensure
		s.quit
	end
}
if not do_dl
	lister.join
	exit
end

dlers = Array.new(nthreads-1) {
	start_dler(group, m, list, lister)
}

lister.join

dlers << start_dler(group, m, list, lister)

dlers.each { |t| t.join }

system 'parrar-sh', '.'