#! /usr/local/bin/ruby

require 'socket'
require 'timeout'

class SMTPForward
	attr_accessor :filter, :error, :permanent, :code
	def initialize(filter, port = 10026, host = 'localhost')
		@filter = filter
		@host = host
		@port = port
		@error = ''
		@code = 0
		@permanent = false
	end
	def begin
		begin
			smtp_connect
			l = smtp_gets
			if(l[0] / 100 != 2) then
				return [ l[0], l[1] ]
			end
			smtp_puts("ehlo #{$apphost}")
			l = smtp_gets
			if(l[0] / 100 != 2) then
				return [ l[0], l[1].to_a.join(', ') ]
			end
			if(@filter.xf) then
				xf = l[1].find { |e| e =~ /^XFORWARD/i }
				if(xf) then
					xl = 'xforward'
					xf.split(/ /)[1..-1].each do |v|
						if(@filter.xf[v]) then
							xl << " " + v + "=" + @filter.xf[v]
						end
					end
					if(xl != 'xforward') then
						smtp_puts(xl)
						l = smtp_gets
						if(l[0] / 100 != 2) then
							return [ l[0], l[1].to_a.join(', ') ]
						end
					end
				end
			end
			smtp_puts("mail from:<#{@filter.from}>")
			l = smtp_gets
			if(l[0] / 100 != 2) then
				return [ l[0], l[1].to_a.join(', ') ]
			end
		rescue SMTPFException => e
			return [ 451, "4.3.0 Queing error, #{e.to_s}" ]
		end
	end
	def rcpt_to(to)
		begin
			smtp_puts("rcpt to:<#{to}>")
			l = smtp_gets
			return [ l[0], l[1].to_a.join(', ') ]
		rescue SMTPFException => e
			return [ 451, "4.3.0 Queing error, #{e.to_s}" ]
		end
	end
	def data()
		begin
			smtp_puts("data")
			l = smtp_gets
			return [ l[0], l[1].to_a.join(', ') ] if(l[0] / 100 != 3)
			@filter.body.each do |l|
				smtp_puts(l.gsub(/^\./, '..'))
			end
			smtp_puts('.')
			l = smtp_gets
		rescue SMTPFException => e
			return [ 451, "4.3.0 Queing error, #{e.to_s}" ]
		end
		begin
			smtp_puts("quit")
			smtp_gets
		rescue Exception => e
		end
		@sock.close
		return l
	end
    private
    	def smtp_connect
		begin
			Timeout.timeout(10) do
				@sock = TCPSocket.new(@host, @port)
			end
		rescue Timeout::Error => e
			raise SMTPFException, "timeout"
		rescue SystemCallError => e
			raise SMTPFException, e.to_s
		rescue Exception => e
			raise SMTPFException, "unexpected (#{e.to_s})"
		end		
	end
	def smtp_gets
		c = 0
		t = []
		begin
			Timeout.timeout(10) do
				while(true)
					r = @sock.gets.chomp
					puts "X<< " + r if($ldebug)
					if(r !~ /^(\d{3})([ -])(.*)$/) then
						raise SMTPFException, "unrecognized response (#{r})"
					else
						c = $1.to_i
						t.push($3)
						break unless($2 == '-')
					end
				end
			end
		rescue Timeout::Error => e
			raise SMTPFException, "timeout"
		rescue SystemCallError => e
			raise SMTPFException, e.to_s
		rescue Exception => e
			raise SMTPFException, "unexpected (#{e.to_s})"
		end		
		return [ c, (t.length == 1 ? t[0] : t) ]
	end
	def smtp_puts(r)
		begin
			Timeout.timeout(10) do
				puts "X>> " + r if($ldebug)
				@sock.print(r + "\r\n")
			end
		rescue Timeout::Error => e
			raise SMTPFException, "timeout"
		rescue SystemCallError => e
			raise SMTPFException, e.to_s
		rescue Exception => e
			raise SMTPFExcpeiton, "unexpected (#{e.to_s})"
		end
	end

end

	

class SMTPFException < SystemCallError
	attr_accessor :message
	def initialize(message)
		super(message)
	end
end