import time
import threading
class SnowflakeGenerator:
 def __init__(self, worker_id=0, datacenter_id=0):
 self.worker_id = worker_id
 self.datacenter_id = datacenter_id
 self.sequence = 0
 self.last_timestamp = -1
 self.lock = threading.Lock()

 self.worker_id_bits = 5
 self.datacenter_id_bits = 5
 self.max_worker_id = -1 ^ (-1 << self.worker_id_bits)
 self.max_datacenter_id = -1 ^ (-1 << self.datacenter_id_bits)
 self.sequence_bits = 12

 self.worker_id_shift = self.sequence_bits
 self.datacenter_id_shift = self.sequence_bits + self.worker_id_bits
 self.timestamp_left_shift = self.sequence_bits + self.worker_id_bits + self.datacenter_id_bits
 self.sequence_mask = -1 ^ (-1 << self.sequence_bits)

 if self.worker_id > self.max_worker_id or self.worker_id < 0:
 raise ValueError(f"worker ID can't be greater than {self.max_worker_id} or less than 0")
 if self.datacenter_id > self.max_datacenter_id or self.datacenter_id < 0:
 raise ValueError(f"datacenter ID can't be greater than {self.max_datacenter_id} or less than 0")

 def _current_time(self):
 return int(time.time() * 1000)

 def _wait_next_millis(self, last_timestamp):
 timestamp = self._current_time()
 while timestamp <= last_timestamp:
 timestamp = self._current_time()
 return timestamp

 def generate_id(self):
 with self.lock:
 timestamp = self._current_time()

 if timestamp < self.last_timestamp:
 raise ValueError("Clock moved backwards. Refusing to generate ID")

 if timestamp == self.last_timestamp:
 self.sequence = (self.sequence + 1) & self.sequence_mask
 if self.sequence == 0:
 timestamp = self._wait_next_millis(self.last_timestamp)
 else:
 self.sequence = 0

 self.last_timestamp = timestamp

 return ((timestamp << self.timestamp_left_shift) |
 (self.datacenter_id << self.datacenter_id_shift) |
 (self.worker_id << self.worker_id_shift) |
 self.sequence)

snowflake = SnowflakeGenerator(worker_id=1)