snowflake_id.rb

class SnowflakeId < ApplicationService
  MAC_ADDRESS_PATTERN = /(?:(?:(?:[a-f0-9]{2}:){5})|(?:(?:[a-f0-9]{2}-){5}))[a-f0-9]{2}/i
  MAC_ADDRESS = lambda { 
    address = RUBY_PLATFORM =~ /darwin/ ? `ifconfig` : `cat /sys/class/net/*/address`
    address.match(MAC_ADDRESS_PATTERN).to_s.delete(':')
  }.call
  NODE_ID = -> { (MAC_ADDRESS.to_i(16) % 1023).to_s(2).rjust(10, '0') }.call
  SEQUENCE_STARTED_AT = 1671750375309
  COUNTER_MAX = 4096
  
  def call
    counter
    ['0', epoch_time, NODE_ID, counter].join.to_i(2)
  end

  private

  def epoch_time
    @epoch_time ||= (DateTime.current.strftime("%Q").to_i - SEQUENCE_STARTED_AT).to_s(2).rjust(41, '0')
  end

  def counter
    if epoch_time != Thread.current[:last_epoch_time]
      Thread.current[:last_epoch_time] = epoch_time
      Thread.current[:snowflake_counter] = 0
    end
    if Thread.current[:snowflake_counter].to_i >= COUNTER_MAX
      @epoch_time = nil
      return counter 
    end
    @counter ||= (Thread.current[:snowflake_counter] += 1).to_s(2).rjust(12, '0')
  end
end

def testing
  integer = DateTime.current.strftime("%Q").to_i.to_s(2)
  puts integer
  time = integer
  puts time
  time = time.chars.each_slice(4).map(&:join).join(' ')
  puts time
  time = "%08b" % integer
  puts time
  time = time.chars.each_slice(4).map(&:join).join(' ')
  puts time
  time
end