/*
    * Copyright 2013-2014 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.web;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import org.springframework.batch.admin.domain.DetailedJobInfo;
  import org.springframework.batch.admin.domain.DetailedJobInfoResource;
  import org.springframework.batch.admin.domain.JobExecutionInfo;
  import org.springframework.batch.admin.domain.NoSuchBatchJobException;
  import org.springframework.batch.core.JobExecution;
  import org.springframework.batch.core.launch.NoSuchJobException;
  import org.springframework.data.domain.PageImpl;
  import org.springframework.data.domain.Pageable;
  import org.springframework.data.web.PagedResourcesAssembler;
  import org.springframework.hateoas.ExposesResourceFor;
  import org.springframework.hateoas.PagedResources;
  import org.springframework.http.HttpStatus;
  import org.springframework.web.bind.annotation.PathVariable;
  import org.springframework.web.bind.annotation.RequestMapping;
  import org.springframework.web.bind.annotation.RequestMethod;
  import org.springframework.web.bind.annotation.ResponseStatus;
  import org.springframework.web.bind.annotation.RestController;
  
  
  /**
   * Controller for batch jobs and job instances, job executions on a given batch job.
   * 
   * @author Dave Syer
   * @author Ilayaperumal Gopinathan
   * @author Andrew Eisenberg
   * @since 2.0
   * 
   */
  @RestController
  @RequestMapping("/batch/configurations")
  @ExposesResourceFor(DetailedJobInfoResource.class)
  public class BatchJobsController extends AbstractBatchJobsController {
  
  	/**
  	 * Get the paged resources of {@link org.springframework.batch.admin.domain.DetailedJobInfoResource}
  	 * 
  	 * @param pageable the paging metadata
  	 * @param assembler the paged resource assembler of type {@link org.springframework.batch.admin.domain.DetailedJobInfo}
  	 */
  	@RequestMapping(value = "", method = RequestMethod.GET)
  	@ResponseStatus(HttpStatus.OK)
  	public PagedResources<DetailedJobInfoResource> jobs(Pageable pageable,
  			PagedResourcesAssembler<DetailedJobInfo> assembler) {
  		int total = jobService.countJobs();
  		Collection<String> names = jobService.listJobs(pageable.getOffset(), pageable.getPageSize());
  		List<DetailedJobInfo> detailedJobs = new ArrayList<DetailedJobInfo>();
  		for (String name : names) {
  			detailedJobs.add(getJobInfo(name));
  		}
  		return assembler.toResource(
  				new PageImpl<DetailedJobInfo>(detailedJobs, pageable, total),
  				jobInfoResourceAssembler);
  	}
  
  	/**
  	 * @param jobName name of the job
  	 * @return ExpandedJobInfo for the given job name
  	 */
  	@RequestMapping(value = "/{jobName}", method = RequestMethod.GET)
  	@ResponseStatus(HttpStatus.OK)
  	public DetailedJobInfoResource jobinfo(@PathVariable String jobName) {
  		return getJobInfoResource(jobName);
  	}
  
  	/**
  	 * @param jobName
  	 * @return the detailed job info resource for the given job name.
  	 */
  	private DetailedJobInfoResource getJobInfoResource(String jobName) {
  		return jobInfoResourceAssembler.toResource(getJobInfo(jobName));
  	}
  
  	/**
  	 * Get detailed job info
  	 *
  	 * @param jobName name of the job
  	 * @return a job info for this job
 	 */
 	private DetailedJobInfo getJobInfo(String jobName) {
 		boolean launchable = jobService.isLaunchable(jobName);
 		try {
 			int count = jobService.countJobExecutionsForJob(jobName);
 			return new DetailedJobInfo(jobName, count, launchable,
 					jobService.isIncrementable(jobName),
 					getLastExecution(jobName));
 		}
 		catch (NoSuchJobException e) {
 			throw new NoSuchBatchJobException(jobName);
 		}
 	}
 
 	/**
 	 * @param jobName name of the batch job
 	 * @return Last job execution info
 	 * @throws org.springframework.batch.core.launch.NoSuchJobException
 	 */
 	private JobExecutionInfo getLastExecution(String jobName) throws NoSuchJobException {
 		Collection<JobExecution> executions = jobService.listJobExecutionsForJob(jobName, 0, 1);
 		if (executions.size() > 0) {
 			return new JobExecutionInfo(executions.iterator().next(), timeZone);
 		}
 		else {
 			return null;
 		}
 	}
 
 }