/*
    * 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 org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.springframework.batch.admin.domain.NoSuchBatchJobException;
  import org.springframework.batch.admin.domain.NoSuchBatchJobInstanceException;
  import org.springframework.batch.admin.service.NoSuchStepExecutionException;
  import org.springframework.batch.core.JobParametersInvalidException;
  import org.springframework.batch.core.launch.JobExecutionNotRunningException;
  import org.springframework.batch.core.launch.NoSuchJobExecutionException;
  import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
  import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException;
  import org.springframework.batch.core.repository.JobRestartException;
  import org.springframework.hateoas.VndErrors;
  import org.springframework.http.HttpStatus;
  import org.springframework.util.StringUtils;
  import org.springframework.web.bind.MissingServletRequestParameterException;
  import org.springframework.web.bind.annotation.ControllerAdvice;
  import org.springframework.web.bind.annotation.ExceptionHandler;
  import org.springframework.web.bind.annotation.ResponseBody;
  import org.springframework.web.bind.annotation.ResponseStatus;
  
  /**
   * Central class for behavior common to all REST controllers.
   *
   * @author Eric Bottard
   * @author Gunnar Hillert
   * @author Ilayaperumal Gopinathan
   * @author Michael Minella
   * @since 2.0
   */
  @ControllerAdvice
  public class RestControllerAdvice {
  
  	private final Log logger = LogFactory.getLog(this.getClass());
  
  	/*
  	 * Note that any controller-specific exception handler is resolved first. So for example, having a
  	 * onException(Exception e) resolver at a controller level will prevent the one from this class to be triggered.
  	 */
  
  	/**
  	 * Handles the case where client submitted an ill valued request (missing parameter).
  	 */
  	@ExceptionHandler
  	@ResponseStatus(HttpStatus.BAD_REQUEST)
  	@ResponseBody
  	public VndErrors onMissingServletRequestParameterException(MissingServletRequestParameterException e) {
  		String logref = logDebug(e);
  		return new VndErrors(logref, e.getMessage());
  	}
  
  	/**
  	 * Handles the general error case. Report server-side error.
  	 */
  	@ExceptionHandler(Exception.class)
  	@ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
  	@ResponseBody
  	public VndErrors onException(Exception e) {
  		String logref = logError(e);
  		String msg = StringUtils.hasText(e.getMessage()) ? e.getMessage() : e.getClass().getSimpleName();
  		return new VndErrors(logref, msg);
  	}
  
  	@ResponseBody
  	@ExceptionHandler
  	@ResponseStatus(HttpStatus.NOT_FOUND)
  	public VndErrors onNoSuchJobExecutionException(NoSuchJobExecutionException e) {
  		String logref = logDebug(e);
  		return new VndErrors(logref, e.getMessage());
  	}
  
  	@ResponseBody
  	@ExceptionHandler
  	@ResponseStatus(HttpStatus.NOT_FOUND)
  	public VndErrors onJobExecutionNotRunningException(JobExecutionNotRunningException e) {
  		String logref = logDebug(e);
  		return new VndErrors(logref, e.getMessage());
  	}
  
  	@ResponseBody
  	@ExceptionHandler
 	@ResponseStatus(HttpStatus.NOT_FOUND)
 	public VndErrors onNoSuchStepExecutionException(NoSuchStepExecutionException e) {
 		String logref = logDebug(e);
 		return new VndErrors(logref, e.getMessage());
 	}
 
 	private String logDebug(Throwable t) {
 		logger.debug("Caught exception while handling a request", t);
 		// TODO: use a more semantically correct VndError 'logref'
 		return t.getClass().getSimpleName();
 	}
 
 	private String logError(Throwable t) {
 		logger.error("Caught exception while handling a request", t);
 		// TODO: use a more semantically correct VndError 'logref'
 		return t.getClass().getSimpleName();
 	}
 
 	@ResponseBody
 	@ExceptionHandler
 	@ResponseStatus(HttpStatus.BAD_REQUEST)
 	public VndErrors onJobExecutionAlreadyRunningException(JobExecutionAlreadyRunningException e) {
 		String logref = logDebug(e);
 		return new VndErrors(logref, e.getMessage());
 	}
 
 	@ResponseBody
 	@ExceptionHandler
 	@ResponseStatus(HttpStatus.BAD_REQUEST)
 	public VndErrors onJobRestartException(JobRestartException e) {
 		String logref = logDebug(e);
 		return new VndErrors(logref, e.getMessage());
 	}
 
 	@ResponseBody
 	@ExceptionHandler
 	@ResponseStatus(HttpStatus.BAD_REQUEST)
 	public VndErrors onJobInstanceAlreadyCompleteException(JobInstanceAlreadyCompleteException e) {
 		String logref = logDebug(e);
 		return new VndErrors(logref, e.getMessage());
 	}
 
 	@ResponseBody
 	@ExceptionHandler
 	@ResponseStatus(HttpStatus.NOT_FOUND)
 	public VndErrors onNoSuchJobException(NoSuchBatchJobException e) {
 		String logref = logDebug(e);
 		return new VndErrors(logref, e.getMessage());
 	}
 
 	@ResponseBody
 	@ExceptionHandler
 	@ResponseStatus(HttpStatus.NOT_FOUND)
 	public VndErrors onNoSuchJobInstanceException(NoSuchBatchJobInstanceException e) {
 		String logref = logDebug(e);
 		return new VndErrors(logref, e.getMessage());
 	}
 
 	@ResponseBody
 	@ExceptionHandler
 	@ResponseStatus(HttpStatus.BAD_REQUEST)
 	public VndErrors onJobParametersInvalidException(JobParametersInvalidException e) {
 		String logref = logDebug(e);
 		return new VndErrors(logref, e.getMessage());
 	}
 }