package jalview.ws2;

import java.io.IOException;
import java.util.List;

import jalview.ws2.utils.WSJobList;

/**
 * {@link WebServiceWorkerI} interface is an extension of {@link PollableTaskI}
 * that adds getter methods for fields that are specific for the web service
 * tasks such as uid, sub-jobs and underlying web service client as well as a
 * method to add listeners to the worker events. {@link WebServiceWorkerI}
 * objects perform operations needed to start, poll and finalize jobs running on
 * the server as well as store sub-jobs created in the process. They use their
 * associated {@link WebServiceI} object to submit and poll the jobs and fetch
 * and parse the result when it's ready.
 * 
 * @author mmwarowny
 *
 */
public interface WebServiceWorkerI extends PollableTaskI
{
  /**
   * Get unique identifier of this worker. Identifier should be randomly
   * generated on object creation and must remain unchanged. Unique id can be
   * generated using {@link jalview.util.MathUtils#getUID}.
   * 
   * @return worker unique id
   */
  long getUID();

  /**
   * Get the sub-jobs created by the worker during job submission.
   * 
   * @return sub-jobs
   */
  WSJobList getJobs();

  /**
   * Gather and parse input data and submit one or more jobs to the web service
   * using associated {@link WebServiceI} object.
   */
  void start() throws IOException;

  boolean poll() throws IOException;

  WebServiceI getWebService();

  /**
   * Check if all sub-jobs finished execution and return whether this task has
   * completed.
   */
  default boolean isDone()
  {
    if (getJobs().size() == 0)
      return false;
    for (WSJob job : getJobs())
    {
      if (!job.getStatus().isDone() && !job.getStatus().isFailed())
        return false;
    }
    return true;
  }

  void done();

  /**
   * Add worker listeners to this worker that will be notified about any state
   * changes to this worker.
   * 
   * @param listener
   *          listener to add
   */
  public void addListener(WebServiceWorkerListener listener);
}