/*
 * 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.log4j.spi;

import org.apache.log4j.Category;
import org.apache.log4j.DefaultThrowableRenderer;

/**
 * ThrowableInformation is log4j's internal representation of throwables. It essentially consists of a string array,
 * called 'rep', where the first element, that is rep[0], represents the string representation of the throwable (i.e.
 * the value you get when you do throwable.toString()) and subsequent elements correspond the stack trace with the top
 * most entry of the stack corresponding to the second entry of the 'rep' array that is rep[1].
 *
 * @author Ceki G&uuml;lc&uuml;
 */
public class ThrowableInformation implements java.io.Serializable {

    static final long serialVersionUID = -4748765566864322735L;

    private transient Throwable throwable;
    private transient Category category;
    private String[] rep;

    public ThrowableInformation(Throwable throwable) {
        this.throwable = throwable;
    }

    /**
     * Create a new instance.
     *
     * @param throwable throwable, may not be null.
     * @param category  category used to obtain ThrowableRenderer, may be null.
     * @since 1.2.16
     */
    public ThrowableInformation(Throwable throwable, Category category) {
        this.throwable = throwable;
        this.category = category;
    }

    /**
     * Create new instance.
     *
     * @param r String representation of throwable.
     * @since 1.2.15
     */
    public ThrowableInformation(final String[] r) {
        if (r != null) {
            rep = (String[]) r.clone();
        }
    }

    public Throwable getThrowable() {
        return throwable;
    }

    public synchronized String[] getThrowableStrRep() {
        if (rep == null) {
            ThrowableRenderer renderer = null;
            if (category != null) {
                LoggerRepository repo = category.getLoggerRepository();
                if (repo instanceof ThrowableRendererSupport) {
                    renderer = ((ThrowableRendererSupport) repo).getThrowableRenderer();
                }
            }
            if (renderer == null) {
                rep = DefaultThrowableRenderer.render(throwable);
            } else {
                rep = renderer.doRender(throwable);
            }
        }
        return (String[]) rep.clone();
    }
}
