text: import datetime
  
  from django.db import models
  
  from zerver.models import AbstractPushDeviceToken
  from analytics.models import BaseCount
  
  def get_remote_server_by_uuid(uuid: str) -> 'RemoteZulipServer':
      return RemoteZulipServer.objects.get(uuid=uuid)
  
  class RemoteZulipServer(models.Model):
      UUID_LENGTH = 36
      API_KEY_LENGTH = 64
      HOSTNAME_MAX_LENGTH = 128
  
      uuid = models.CharField(max_length=UUID_LENGTH, unique=True)  # type: str
      api_key = models.CharField(max_length=API_KEY_LENGTH)  # type: str
  
      hostname = models.CharField(max_length=HOSTNAME_MAX_LENGTH)  # type: str
      contact_email = models.EmailField(blank=True, null=False)  # type: str
      last_updated = models.DateTimeField('last updated', auto_now=True)  # type: datetime.datetime
  
      def __str__(self) -> str:
          return "<RemoteZulipServer %s %s>" % (self.hostname, self.uuid[0:12])
  
  # Variant of PushDeviceToken for a remote server.
  class RemotePushDeviceToken(AbstractPushDeviceToken):
      server = models.ForeignKey(RemoteZulipServer, on_delete=models.CASCADE)  # type: RemoteZulipServer
      # The user id on the remote server for this device device this is
      user_id = models.BigIntegerField(db_index=True)  # type: int
  
      class Meta:
          unique_together = ("server", "user_id", "kind", "token")
  
      def __str__(self) -> str:
          return "<RemotePushDeviceToken %s %s>" % (self.server, self.user_id)
  
  class RemoteInstallationCount(BaseCount):
      server = models.ForeignKey(RemoteZulipServer, on_delete=models.CASCADE)  # type: RemoteZulipServer
      # The remote_id field lets us deduplicate data from the remote server
      remote_id = models.IntegerField(db_index=True)  # type: int
  
      class Meta:
          unique_together = ("server", "property", "subgroup", "end_time")
  
      def __str__(self) -> str:
          return "<InstallationCount: %s %s %s>" % (self.property, self.subgroup, self.value)
  
  # We can't subclass RealmCount because we only have a realm_id here, not a foreign key.
  class RemoteRealmCount(BaseCount):
      server = models.ForeignKey(RemoteZulipServer, on_delete=models.CASCADE)  # type: RemoteZulipServer
      realm_id = models.IntegerField(db_index=True)  # type: int
      # The remote_id field lets us deduplicate data from the remote server
      remote_id = models.IntegerField(db_index=True)  # type: int
  
      class Meta:
          unique_together = ("server", "realm_id", "property", "subgroup", "end_time")
          index_together = ["property", "end_time"]
  
      def __str__(self) -> str:
          return "%s %s %s %s %s" % (self.server, self.realm_id, self.property, self.subgroup, self.value)
  