class SimpleRotate

  def initialize(log_file=$0+".log", max_size=1000000, rotate=true, log_format=".", log_mess=true)
    @log_file   = log_file
    @max_size   = max_size
    @log_format = log_format
    @rotate     = rotate
    @log_mess   = log_mess
    @rotate = false if @rotate == 0

    if File.exist?(@log_file)
      if over_size(@log_file)
        ch_name(@log_file)
        @logf = File.open(@log_file, "w+")
      else
        @logf = File.open(@log_file, "a+")
      end
    else
      @logf = File.open(@log_file, "w+")
    end
    @size = File.size(@log_file)
    w("\n----- Start Logs [Date: #{get_time('milestone')}] [PID: #{$$}] -----\n") if @log_mess
  end

  def over_size(f)
    if File.size(f) > @max_size
      return true
    else
      return false
    end
  end

  def ch_name(f)
    cnt      = 1
    rename_f = "#{@log_file}#{@log_format}#{cnt}"

    if File.exist?(rename_f)
      while File.exist?(rename_f)
        cnt     += 1
        rename_f = "#{@log_file}#{@log_format}#{cnt}"
      end
      wait_rename = Array.new
      for nc in 1...cnt
        break if @rotate == 1
        wait_rename << "File.rename('#{@log_file}#{@log_format}#{nc}', '#{@log_file}#{@log_format}#{nc+1}')"
        if @rotate
          next if @rotate.class == TrueClass
          break if @rotate <= nc+1
        end
      end

      wait_rename.reverse!
      wait_rename.each{ |do_rename|
        eval(do_rename)
      }
      File.rename(f, "#{@log_file}#{@log_format}1") if @rotate

    else
      File.rename(f, rename_f) if @rotate
    end
  end

  def get_time(request)
    if request == "party"
      return Time.now.strftime("[%Y/%m/%d %H:%M:%S] ")
    elsif request == "milestone"
      return Time.now.strftime("%Y/%m/%d %H:%M:%S")
    end
  end

  def flush
    e
    ch_name(@log_file)
    @logf = File.open(@log_file, "w+")
    @size = File.size(@log_file)
    w("\n----- Start Logs [Date: #{get_time('milestone')}] [PID: #{$$}] -----\n") if @log_mess
  end

  def w(str, output=false, rec_time=false)
    if rec_time
      @logf.puts(get_time('party')+str)
      puts get_time('party')+str if output
    else
      @logf.puts(str)
      puts str if output
    end
  end

  def e
    w("----- End Logs [Date: #{get_time('milestone')}] [PID: #{$$}] -----\n") if @log_mess
    @logf.close
  end

end