package jalview.ws2.actions.api;

import java.util.List;

import jalview.ws2.api.JobStatus;

/**
 * {@code TaskI} objects represent running services. Tasks are created by
 * concrete implementations of {@link ActionI} and provide a view of the state
 * of the underlying job(s).
 * 
 * @author mmwarowny
 *
 * @param <T>
 *          task result type
 */
public interface TaskI<T>
{
  /**
   * Get the universal identifier of this task.
   * 
   * @return identifier
   */
  long getUid();

  /**
   * Get the current status of the task. The resultant status should be a
   * combination of individual sub-job statuses.
   * 
   * @return global status of
   */
  JobStatus getStatus();

  /**
   * Get the current list of sub-jobs of that task.
   * 
   * @return sub-jobs
   */
  List<? extends JobI> getSubJobs();

  /**
   * Get the last result of the task or {@code null} if not present. Note that
   * the result is subject to change for restartable tasks.
   * 
   * @return last task result
   */
  T getResult();

  /**
   * Cancel the task, stop all sub-jobs running on a server and stop all threads
   * managing this task.
   */
  void cancel();
}