/*
 * 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.
     * 
     * @since 1.2.15
     * @param r String representation of throwable.
     */
    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();
    }
}
