/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.hadoop.yarn.webapp;

import java.io.FileNotFoundException;
import java.io.IOException;

import javax.servlet.http.HttpServletResponse;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.ipc.RemoteException;
import org.apache.hadoop.security.authorize.AuthorizationException;

import com.google.inject.Singleton;

/**
 * Handle webservices jersey exceptions and create json or xml response
 * with the ExceptionData.
 */
@Singleton
@Provider
public class GenericExceptionHandler implements ExceptionMapper<Exception> {
  public static final Log LOG = LogFactory
      .getLog(GenericExceptionHandler.class);

  private @Context
  HttpServletResponse response;

  @Override
  public Response toResponse(Exception e) {
    if (LOG.isTraceEnabled()) {
      LOG.trace("GOT EXCEPITION", e);
    }
    // Don't catch this as filter forward on 404
    // (ServletContainer.FEATURE_FILTER_FORWARD_ON_404)
    // won't work and the web UI won't work!
    if (e instanceof com.sun.jersey.api.NotFoundException) {
      return ((com.sun.jersey.api.NotFoundException) e).getResponse();
    }
    // clear content type
    response.setContentType(null);

    // Convert exception
    if (e instanceof RemoteException) {
      e = ((RemoteException) e).unwrapRemoteException();
    }

    // Map response status
    final Response.Status s;
    if (e instanceof SecurityException) {
      s = Response.Status.UNAUTHORIZED;
    } else if (e instanceof AuthorizationException) {
      s = Response.Status.UNAUTHORIZED;
    } else if (e instanceof FileNotFoundException) {
      s = Response.Status.NOT_FOUND;
    } else if (e instanceof NotFoundException) {
      s = Response.Status.NOT_FOUND;
    } else if (e instanceof IOException) {
      s = Response.Status.NOT_FOUND;
    } else if (e instanceof UnsupportedOperationException) {
      s = Response.Status.BAD_REQUEST;
    } else if (e instanceof IllegalArgumentException) {
      s = Response.Status.BAD_REQUEST;
    } else if (e instanceof NumberFormatException) {
      s = Response.Status.BAD_REQUEST;
    } else if (e instanceof BadRequestException) {
      s = Response.Status.BAD_REQUEST;
    } else {
      LOG.warn("INTERNAL_SERVER_ERROR", e);
      s = Response.Status.INTERNAL_SERVER_ERROR;
    }

    // let jaxb handle marshalling data out in the same format requested
    RemoteExceptionData exception = new RemoteExceptionData(e.getClass().getSimpleName(),
       e.getMessage(), e.getClass().getName());

    return Response.status(s).entity(exception)
        .build();
  }
}
