#!/usr/bin/ruby

class MysqlRailsSessionCleaner
  require 'rubygems'
  require 'mysql'

  DB_USER = 'user'
  DB_PASS = 'pass'
  DB_HOST = 'host'
  DB_DEFAULT = 'mysql'
  LOG_PATH = '/var/log'

  def self.purge_sessions
    log_info = ""
    db = Mysql.real_connect(DB_HOST, DB_USER, DB_PASS, DB_DEFAULT)
    res = db.query("SHOW DATABASES;")
    while row = res.fetch_row do
      db.select_db("#{row[0]}")
      table_res = db.query("SHOW TABLES LIKE 'sessions';")
      while table = table_res.fetch_row do
        if table[0] == 'sessions'
          db.query("DELETE FROM sessions WHERE updated_at < (CURRENT_TIMESTAMP - INTERVAL 3 HOUR)")
          log_info << "Deleted #{db.affected_rows} records from #{row[0]}\n"
        end
      end
    end
    db.close

    # log the info
    File.open( "#{LOG_PATH}/session_cleanr_log", "a" ) do |the_file|
      the_file.puts "\n===== LOG CLEANSE #{Time.now} ====\n"
        the_file.puts "#{log_info}"
        the_file.puts "\n"
    end
    rescue Exception => ex
      puts ex
  end
end

MysqlRailsSessionCleaner::purge_sessions