require 'socket'

# watches a file, announces new lines on irc

# (c) Yoann Guillot 2006
# distributed under the terms of the WtfPLv2 (zoy.org)

class IrcClient
	attr_accessor :host, :port, :nick, :uhost, :chan, :timeout, :msg_interval
	def initialize(host, port = 6667)
		@host = host
		@port = port
		@uhost= 'rb rb rb :rb'

		@status = ''

		# seconds
		@timeout = 300	# ping if no message during this, reconnect if no pong during this again
		@allow = Time.now - 10	# next time to watch for a new line (antiflood)
		@at = []
	end

	def connect
		@sock = TCPSocket.open @host, @port
		@sentping = false
		@lastmsg = Time.now
		send "user #@uhost"
		send "nick #@nick"
		send "join #@chan"
		@chan = @chan.split(' ').first || @chan
	end

	def run
		connect
		loop do
			r, w, e = IO.select [@sock], nil, nil, 0.5
			monitor if Time.now > @allow
			if not r
				handle_timeout if Time.now - @lastmsg >= @timeout
			elsif r.include? @sock
				@lastmsg = Time.now
				handle_sock @sock.gets.chomp
			end
		end
	end

	def send(l)
		if @allow > Time.now
			@allow = Time.now
		elsif @allow < Time.now - 10
			@allow = Time.now - 10
		end
		@allow += 2
		puts "#{Time.now.strftime '%H:%M'} > #{l}" if $VERBOSE
		@sock.write l + "\r\n"
	end

	def handle_timeout
		if @sentping
			raise 'server ping timeout' if Time.now - @sentping >= @timeout
		else
			send  'ping :stillalive'
			@sentping = Time.now
		end
	end

	def pm l
		send "PRIVMSG #@chan :#{l.empty? ? ' ' : l[0, 512]}"
	end

	def handle_sock l
		puts "#{Time.now.strftime '%H:%M'} #{l}" if $VERBOSE and l !~ /^ping/i
		case l
		when /^:jj!.* PRIVMSG .* :#@nick:? (.*)/
			cmd = $1.strip
			case cmd
			when 'status'
				pm @status
			when 'quit'
				send 'quit requested'
			when /^cat (.*)/
				val = $1
				begin
				File.open(val) { |fd|
					fd.each_line { |l|
						pm l.chomp
					}
				}
				pm '<empty>' if File.size(val) == 0
				rescue
					pm "read #{val}: #$!"
				end
			else
				pm "#{cmd} unknown"
			end
		when /^ping (.*)/i
			send "pong #$1"
		when /pong.*stillalive/i
			@sentping = nil
		end
	end

	attr_accessor :file, :filesize
	def monitor
		if File.size(@file) != @filesize
			File.open(@file, 'rb') { |fd|
				fd.pos = @filesize
				l = fd.gets
				if l and not l.empty?	# no chomp, send newlines present in the file
					pm l.chomp
					case l
					when /sleep .* => (.*)/
						@status = l.chomp
					end
				end
				@filesize = fd.pos
			}
		end
	end
end

if __FILE__ == $0
	if ARGV.empty?
		c = IrcClient.new 'irc.net'
		c.chan = '#bla'
		c.nick = 'logger'
		c.file = 'watched/file'
		c.filesize = [0, File.size(c.file) - 400].max	# backlog 400 last octets on startup
		c.run
	else
		$stdin.close rescue nil
		$stdout.close rescue nil
		$stderr.close rescue nil
		exit if fork	# daemonize
		loop do
			exec "ruby #$0" if not pid = fork
			sleep 300
			Process.waitpid(pid)
		end
	end
end