public bool CheckInstanceRunning()

in tools/gsnapshot/Instances.cs [135:192]
58 lines of code
19 McCabe index (conditional complexity)

    public bool CheckInstanceRunning(string projectId, ComputeData.Instance instance,
                                     bool forceStopServer, string operation) {
      if (instance.Status != "RUNNING" && instance.Status != "TERMINATED") {
        _logger.LogCritical(
            $"Instance state is not in a good state ({instance.Status}), waiting for 10 seconds...");
        bool statusOk = false;
        for (int i = 0; i < 10 && !statusOk; i++) {
          System.Threading.Thread.Sleep(1000);
          instance = GetInstance(projectId, instance);
          if (instance.Status != "RUNNING" || instance.Status != "TERMINATED") {
            statusOk = true;
          }
        }
        if (!statusOk) {
          _logger.LogCritical(
              $"Instance state is not in a good state ({instance.Status}), timed out after 10 seconds.");
          System.Environment.Exit(5);
        }
      }
      if (instance.Status == "RUNNING") {
        bool stopServer = forceStopServer;
        if (!forceStopServer) {
          if (operation == "snapshot") {
            _logger.LogWarning($"Instance is running, do you want to stop it first?");
            _logger.LogInformation(
                $"(Stopping an instance guarantees a consistent snapshot from a clean shutdown, but is not required)");
          }
          if (operation == "rollback") {
            _logger.LogWarning($"Instance is running, do you want proceed stopping it?");
            _logger.LogInformation(
                $"(Instance needs to be stopped to reattach disks from snapshots)");
          }
          stopServer = _utils.GetYesNo("Stop server (Y/n)?", true);
        }
        if (stopServer) {
          _logger.LogWarning($"Stopping instance {instance.Name} now...");
          bool serverStopped = StopInstance(projectId, instance).GetAwaiter().GetResult();
          do {
            var stoppingInstance = GetInstance(projectId, instance);
            if (stoppingInstance.Status == "TERMINATED") {
              _logger.LogInformation("Instance has been stopped successfully.");
              break;
            }
            if (stoppingInstance.Status != "RUNNING" && stoppingInstance.Status != "STOPPING") {
              _logger.LogCritical(
                  $"Unknown status encountered during instance stop ({stoppingInstance.Status}), but continuing.");
              break;
            }
            System.Threading.Thread.Sleep(750);
          } while (true);
        }
        if (!stopServer && operation == "rollback") {
          _logger.LogCritical("Instance needs to be stopped to reattach rolled back disks!");
          System.Environment.Exit(6);
        }
      }
      return instance.Status == "RUNNING";
    }