#! /usr/local/bin/ruby

##################################################################
#### Net::NNTP module, feeding oriented
####
#### Written by F. Senault (fred@lacave.net), free to use,
####   redistribute, modify.
#### No warranty at all, implied or whatever.  Use at your own
####   risk.
##################################################################

require 'socket'

module Net

	class NNTP

	    public
		attr_accessor :reader
		attr_reader :address, :ip, :port, :lastrep

		@@debug = false

		def NNTP.default_port
			119
		end
		def NNTP.debug=(debug)
			NNTP::Response.debug = debug
			@@debug = true
		end
		def NNTP.debug()
			@@debug
		end
		def initialize(address, port = nil)
			@address = address
			@port = (port || NNTP.default_port)
			@reader = false
			@started = false
			@socket = nil
			@ip = nil
			@banner = nil
			@lastrep = nil
		end
		def started?
			@started
		end
		
		def NNTP.start(address, port = nil, reader = nil, user = nil, pass = nil, &block)
			n = self.new(address, port)
			n.start(user, pass, reader, &block)
		end
		def start(reader = nil, user = nil, pass = nil, &block)
			if(!block.nil?) then
				begin
					@lastrep = do_start(reader, user, pass)
					block.call(self)
				ensure
					do_finish
				end
			else
				@lastrep = do_start(reader, user, pass)
				return self
			end
		end
		def list(command = '')
			raise "Command before start." if(!@started)
			@lastrep = do_send("list #{command}", true)
		end
		def check(mid)
			raise "Command before start." if(!@started)
			mid = "<#{mid}>" unless(mid[0,1] == '<')
			@lastrep = do_send("check #{mid}")
		end
		def takethis(art)
			raise "Command before start." if(!@started)
			do_send("takethis #{art['Message-ID']}", false, true)
			@lastrep = do_send_raw(art.to_wireformat)
		end
		def article(mid)
			raise "Command before start." if(!@started)
			@lastrep = do_send("article #{mid}", true)
		end
			

		def stop()
			@lastrep = do_finish()
		end

	    private

		def do_start(reader, user, pass)
			@socket = TCPSocket.new(@address, @port)
			r = NNTP::Response.new(@socket)
			if(!r.ok) then
				do_finish
				return r
			end
			if(r.ok && reader == true) then
				r = do_send("mode reader")
				@reader = r.ok
			end
			if(r.ok && !user.nil?) then
				r = do_send("authinfo user #{user}")
			end
			if(r.ok && !pass.nil?) then
				r = do_send("authinfo pass #{pass}")
			end
			@started = true
			r
		end
		def do_finish()
			@started = false
			do_send("quit")
		end
		def do_send(t, long = false, nowait = false)
			puts ">>> " + t if(@@debug)
			@socket.print t + "\r\n"
			NNTP::Response.new(@socket, long) unless(nowait)
		end
		def do_send_raw(t, long = false)
			nl = 0
			t.each do |l|
				l.chomp!
				nl+=1
				@socket.print(l + "\r\n")
			end
			puts ">>> [#{nl} lines]" if(@@debug)
			@socket.print(".\r\n")
			NNTP::Response.new(@socket, long)
		end
	end
	

	class NNTP::Response
	
		attr_reader :code, :desc, :resp
		
		@@debug = false

		def self.debug=(debug)
			@@debug = true
		end
		def self.debug()
			@@debug
		end
		def initialize(datain, long = false)
			@resp = ''
			r = nil
			if(datain.kind_of? IO) then
				r = [ datain.gets.chomp ]
				if(long) then
					while((o = datain.gets.chomp) != '.')
						r.push(o)
					end
				end
			else
				if(long) then
					r = datain.split(/(?:\r|\r\n|\n)/)
				else
					r = [ datain.to_s.chomp ]
				end
			end
			l = r.shift
			re = Regexp.new(/^(\d\d\d)(?: (.*))?$/).match(l)
			if(re.nil?) then
				(@code, @desc) = [ '499', l ]
			else
				(@code, @desc) = re[1,2]
			end
			if(long) then
				r.inject do |@resp, l|
					#@resp = (@resp == '' ? '' : @resp + "\n") + l
					@resp += l + "\n" unless(l == '.')
				end
			end
			puts self.short("<<< ") if(@@debug)
			self
		end
		def ok
			case @code[0,1]
			when '1', '2' then
				true
			else
				false
			end
		end
		def to_s(prefix = '')
			r = "#{prefix}#{@code} #{@desc}\n"
			if(@resp != '') then
				@resp.each do |l|
					r += "#{prefix}#{l}\n"
				end
				r += "#{prefix}.\n"
			end
			r
		end
		def short(prefix = '')
			r = "#{prefix}#{code} #{desc}\n"
			if(@resp != '') then
				r += "#{prefix}[#{@resp.scan(/\n/).length} lines]\n"
				r += "#{prefix}.\n"
			end
			r
		end
	end

	class NNTP::Article
		attr_accessor :body
		def initialize()
			@hdr = {}
			@hdro =  {}
			@body = ''
			@ord = 0
		end
		def []=(key, value)
			if(!key.nil? && key.to_s != '' &&
			   !value.nil? && value.to_s != '') then
				@hdr[key] = value
				@hdro[key] = @ord
				@ord += 1
			end
		end
		def [](key)
			@hdr[key]
		end
		def to_wireformat
			r = ''
			@hdr.keys.sort { |a, b| @hdro[a] <=> @hdro[b] }.each do |k|
				r += "#{k}: #{@hdr[k]}\n"
			end
			r += "\n"
			@body.each do |l|
				l.chomp!
				l = '.' + l if(l[0,1] == '.')
				r += "#{l}\n"
			end
			r
		end
		def to_s
			r = ''
			@hdr.keys.sort { |a, b| @hdro[a] <=> @hdro[b] }.each do |k|
				r += "#{k}: #{@hdr[k]}\n"
			end
			r += "\n"
			@body.each do |l|
				r += "#{l}"
			end
			r
		end
		def to_h
			r = ''
			@hdr.keys.sort { |a, b| @hdro[a] <=> @hdro[b] }.each do |k|
				r += "#{k}: #{@hdr[k]}\n"
			end
			r += "\n"
		end
		def to_h_light
			r = ''
			[ 'From', 'Newsgroups', 'Subject', 'Message-ID', 'Date', 'Path' ].each do |k|
				r += "#{k}: #{@hdr[k]}\n" unless(@hdr[k].nil?)
			end
			r += "\n"
		end
		def self.make_date(d)
			"%s %+05d (%s)" % [ d.strftime("%a, %d %b %Y %H:%M:%S"), d.gmt_offset/36, d.zone ]
		end
	end
end