/*
    * Copyright 2009-2013 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.springframework.batch.admin.integration;
  
  import org.springframework.batch.admin.web.LaunchRequest;
  import org.springframework.batch.core.BatchStatus;
  import org.springframework.batch.core.Job;
  import org.springframework.batch.core.JobExecution;
  import org.springframework.batch.core.JobInstance;
  import org.springframework.batch.core.JobParameters;
  import org.springframework.batch.core.configuration.JobLocator;
  import org.springframework.batch.core.explore.JobExplorer;
  import org.springframework.batch.core.launch.JobParametersNotFoundException;
  import org.springframework.batch.core.launch.NoSuchJobException;
  import org.springframework.batch.integration.launch.JobLaunchRequest;
  import org.springframework.integration.annotation.MessageEndpoint;
  import org.springframework.integration.annotation.ServiceActivator;
  
  import java.util.List;
  
  /**
   * Adapt a job name to a {@link LaunchRequest} for restarting the last failed
   * execution of the {@link Job}. The parameters of the last execution are pulled
   * out of the {@link JobExplorer}.
   * 
   * @author Dave Syer
   * @author Michael Minella
   * 
   */
  @MessageEndpoint
  public class JobNameToJobRestartRequestAdapter {
  
  	private JobLocator jobLocator;
  
  	private JobExplorer jobExplorer;
  
  	public void setJobLocator(JobLocator jobLocator) {
  		this.jobLocator = jobLocator;
  	}
  
  	public void setJobExplorer(JobExplorer jobExplorer) {
  		this.jobExplorer = jobExplorer;
  	}
  
  	@ServiceActivator
  	public JobLaunchRequest adapt(String jobName) throws NoSuchJobException,
  	JobParametersNotFoundException {
  		jobName = jobName.trim();
  		Job job = jobLocator.getJob(jobName);
  		JobParameters jobParameters = getLastFailedJobParameters(jobName);
  		return new JobLaunchRequest(job, jobParameters);
  	}
  
  	/**
  	 * @param jobName name of job to return parameters for
  	 * @return {@link org.springframework.batch.core.JobParameters} for the job requested
  	 * @throws JobParametersNotFoundException
  	 */
  	private JobParameters getLastFailedJobParameters(String jobName)
  			throws JobParametersNotFoundException {
  
  		int start = 0;
  		int count = 100;
  		List<JobInstance> lastInstances = jobExplorer.getJobInstances(jobName,
  				start, count);
  
  		JobParameters jobParameters = null;
  
  		if (lastInstances.isEmpty()) {
  			throw new JobParametersNotFoundException(
  					"No job instance found for job=" + jobName);
  		}
  
  		while (!lastInstances.isEmpty()) {
  
  			for (JobInstance jobInstance : lastInstances) {
  				List<JobExecution> jobExecutions = jobExplorer
  						.getJobExecutions(jobInstance);
  				if (jobExecutions == null || jobExecutions.isEmpty()) {
  					continue;
  				}
  				JobExecution jobExecution = jobExecutions.get(jobExecutions
  						.size() - 1);
  				if (jobExecution.getStatus()
  						.isGreaterThan(BatchStatus.STOPPING)) {
  					jobParameters = jobExecution.getJobParameters();
 					break;
 				}
 			}
 
 			if (jobParameters != null) {
 				break;
 			}
 
 			start += count;
 			lastInstances = jobExplorer.getJobInstances(jobName, start, count);
 
 		}
 
 		if (jobParameters == null) {
 			throw new JobParametersNotFoundException(
 					"No failed or stopped execution found for job=" + jobName);
 		}
 		return jobParameters;
 
 	}
 
 }