require 'observer'
require 'thread'
require 'timeout'
require 'net/http'

module RubyForge
  module MirrorWatch
    class Watcher
      include Observable

      def initialize(host, url, size, interval = 60)
        @host, @url, @interval, @active = host, url, interval, false
        $THREADS << Thread.new do
          while true do
            response, e = nil, nil
            begin
              timeout(@timeout) { response = fetch @host, @url }
            rescue Timeout::Error => e
            rescue SocketError => e
	          rescue Errno::EHOSTUNREACH => e
            rescue Errno::ETIMEDOUT => e
            rescue Errno::ECONNREFUSED => e
            rescue Errno::ECONNRESET => e
            end
            unless e.nil? and response.code == "200" and response.content_length == size
              changed and notify_observers(self, @active = false, response) if @active
            else
              changed and notify_observers(self, @active = true) if !@active
            end
            sleep @interval
          end
        end
      end

      def fetch(host, url)
        Net::HTTP.new(host, 80).get(url)
      end

      attr_reader :active, :host
    end
  end
end