/*
 * Copyright (C) 2011 Red Hat, Inc. and/or its affiliates.
 *
 * 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.jboss.errai.marshalling.client.marshallers;

import org.jboss.errai.common.client.protocols.SerializationParts;
import org.jboss.errai.marshalling.client.api.MarshallingSession;
import org.jboss.errai.marshalling.client.api.json.EJValue;
import org.jboss.errai.marshalling.client.util.MarshallUtil;

/**
 * this marshaller is intentionally not marked ServerMarshaller or ClientMarshaller because it is
 * used only to marshal exceptions not handled elsewhere
 */
public class FallbackExceptionMarshaller extends AbstractNullableMarshaller<Object> {

  public static final FallbackExceptionMarshaller INSTANCE = new FallbackExceptionMarshaller();

  @Override
  public Object[] getEmptyArray() {
    return new Object[0];
  }

  @Override
  public Object doNotNullDemarshall(final EJValue o, final MarshallingSession ctx) {
    return null;
  }

  @Override
  public String doNotNullMarshall(final Object o, final MarshallingSession ctx) {
    Throwable cause = getCause(((Throwable) o));
    String message = null;
    if (cause != null) {
      message = cause.getMessage();
    }

    return "{\"" + SerializationParts.ENCODED_TYPE + "\":\"" + RuntimeException.class.getName() + "\","
                 + "\"" + SerializationParts.OBJECT_ID + "\":\"" + o.hashCode() + "\","
                 + "\"" + "message" + "\":\"" +
                 ((cause != null) ? MarshallUtil.jsonStringEscape(cause.getClass().getName()) : "") +
                 ((message != null) ? ":" + MarshallUtil.jsonStringEscape(message) : "")
        + "\"}";
  }

  Throwable getCause(Throwable e) {
    if (e.getCause() != null) {
      return getCause(e.getCause());
    }
    return e;
  }
}