fs = require 'fs'
readline = require('readline');

exports.countryCounter = (countryCode, cb) ->
  return cb() unless countryCode

  instream = fs.createReadStream("#{__dirname}/../data/geo.txt", {
      flags: 'r',
      encoding: 'utf-8',
      bufferSize: 256 * 1024
  });

  rl = readline.createInterface(instream, null);

  counter = 0
  lines = 0

  rl.on('line', (line) ->
    # process line here
    values = line.split '\t'
    # GEO_FIELD_MIN, GEO_FIELD_MAX, GEO_FIELD_COUNTRY
    # line[0],       line[1],       line[3]
    if values[3] == countryCode then counter++
  );

  rl.on('close', () ->
    cb null, counter
  );