/*
 * Copyright © 2016-2018 European Support Limited
 *
 * 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.openecomp.activityspec.errors;

import java.util.Set;
import javax.validation.ConstraintViolation;
import javax.validation.ConstraintViolationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.ext.ExceptionMapper;
import org.codehaus.jackson.map.JsonMappingException;
import org.hibernate.validator.internal.engine.path.PathImpl;
import org.openecomp.sdc.common.errors.CoreException;
import org.openecomp.sdc.logging.api.Logger;
import org.openecomp.sdc.logging.api.LoggerFactory;

public class DefaultExceptionMapper implements ExceptionMapper<Exception> {

  private static final Logger LOGGER = LoggerFactory.getLogger(DefaultExceptionMapper.class);

  @Override
  public Response toResponse(Exception exception) {
    Response response;
    if (exception instanceof CoreException) {
      response = transform(CoreException.class.cast(exception));
    } else if (exception instanceof ActivitySpecNotFoundException) {
      response = transform(ActivitySpecNotFoundException.class.cast(exception));
    } else if (exception instanceof ConstraintViolationException) {
      response = transform(ConstraintViolationException.class.cast(exception));
    } else if (exception instanceof JsonMappingException) {
      response = transform(JsonMappingException.class.cast(exception));
    } else {
      response = transform(exception);
    }

    return response;
  }

  private Response transform(ActivitySpecNotFoundException notFoundException) {
    LOGGER.error("Transforming ActivitySpecNotFoundException to Error Response  :", notFoundException);
    return generateResponse(Status.NOT_FOUND, new ActivitySpecErrorResponse(notFoundException.getMessage()));
  }

  private Response transform(CoreException coreException) {
    LOGGER.error("Transforming CoreException to Error Response  :", coreException);
    return generateResponse(Status.BAD_REQUEST, new ActivitySpecErrorResponse(coreException.getMessage()));
  }

  private Response transform(ConstraintViolationException validationException) {
    LOGGER.error("Transforming ConstraintViolationException to Error Response :",
        validationException);
    Set<ConstraintViolation<?>> constraintViolationSet = validationException
        .getConstraintViolations();
    String message;

    String fieldName = null;
    if (constraintViolationSet != null) {
      // getting the first violation message for the output response.
      ConstraintViolation<?> constraintViolation = constraintViolationSet.iterator().next();
      message = constraintViolation.getMessage();
      fieldName = ((PathImpl) constraintViolation.getPropertyPath()).getLeafNode().toString();

    } else {
      message = validationException.getMessage();
    }
    return generateResponse(Status.BAD_REQUEST, new ActivitySpecErrorResponse(String.format(message,fieldName)));
  }

  private Response transform(Exception exception) {
    LOGGER.error("Transforming Exception to Error Response " + exception);
    return generateResponse(Status.INTERNAL_SERVER_ERROR, new ActivitySpecErrorResponse(exception.getMessage()));
  }

  private Response transform(JsonMappingException jsonMappingException) {
    LOGGER.error("Transforming JsonMappingException to Error Response " + jsonMappingException);
    return generateResponse(Status.BAD_REQUEST, new ActivitySpecErrorResponse("Invalid Json Input"));
  }

  private Response generateResponse(Response.Status status, ActivitySpecErrorResponse
      activitySpecErrorResponse) {
    return Response.status(status).entity(activitySpecErrorResponse).type(MediaType
        .APPLICATION_JSON).build();
  }
}