require 'net/ping'
require 'ruby-progressbar'

class ProxyFinder

  def initialize
    @progressbar
  end

  def start(files)

    infile = File.open(files[:infile], 'r')
    outfile = File.open(files[:outfile], 'a')

    # Get number of lines in file to set the progress bar's width
    # Rewind the file pointer because apparently `count` advances it to the end
    lines = infile.count
    infile.rewind

    @progressbar = ProgressBar.create(title: 'Checking hosts...',
                                      format: '%a |%b>>%i| %p%% %t',
                                      length: 80,
                                      total: lines)

    infile.readlines.map {|line| line.rstrip}.each do |host|

      # Displaying progress
      @progressbar

      # Extracting IP Address and Port from host
      ip, port = host.split(':')
      port = 80 if port.nil?

      # Carriage return, blanking up to last host length, carriage return
      if Net::Ping::HTTP.new(ip, port).ping?
        outfile.puts host
      end

      @progressbar.increment

    end

    infile.close
    outfile.close

  end

end