/*
 * 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.juli;

import java.util.logging.Formatter;
import java.util.logging.LogRecord;

/**
 * A more compact formatter. Equivalent log4j config:
 *
 * <pre>
 *  log4j.rootCategory=WARN, A1
 *  log4j.appender.A1=org.apache.log4j.ConsoleAppender
 *  log4j.appender.A1.layout=org.apache.log4j.PatternLayout
 *  log4j.appender.A1.Target=System.err
 *  log4j.appender.A1.layout.ConversionPattern=%r %-20.20c{2} %-1.1p %m %n
 * </pre>
 *
 * Example: 1130122891846 Http11BaseProtocol I Initializing Coyote HTTP/1.1 on http-8800
 */
public class JdkLoggerFormatter extends Formatter {

    /**
     * Constructs a new JdkLoggerFormatter.
     */
    public JdkLoggerFormatter() {
    }

    /**
     * Log level value for TRACE.
     */
    public static final int LOG_LEVEL_TRACE = 400;
    /**
     * Log level value for DEBUG.
     */
    public static final int LOG_LEVEL_DEBUG = 500;
    /**
     * Log level value for INFO.
     */
    public static final int LOG_LEVEL_INFO = 800;
    /**
     * Log level value for WARN.
     */
    public static final int LOG_LEVEL_WARN = 900;
    /**
     * Log level value for ERROR.
     */
    public static final int LOG_LEVEL_ERROR = 1000;
    /**
     * Log level value for FATAL.
     */
    public static final int LOG_LEVEL_FATAL = 1000;

    @Override
    public String format(LogRecord record) {
        Throwable t = record.getThrown();
        int level = record.getLevel().intValue();
        String name = record.getLoggerName();
        long time = record.getMillis();
        String message = formatMessage(record);

        if (name == null) {
            name = "";
        }
        if (name.indexOf('.') >= 0) {
            name = name.substring(name.lastIndexOf('.') + 1);
        }

        // Use a string buffer for better performance
        StringBuilder buf = new StringBuilder();

        buf.append(time);

        // Append a readable representation of the log level.
        switch (level) {
            case LOG_LEVEL_TRACE:
                buf.append(" T ");
                break;
            case LOG_LEVEL_DEBUG:
                buf.append(" D ");
                break;
            case LOG_LEVEL_INFO:
                buf.append(" I ");
                break;
            case LOG_LEVEL_WARN:
                buf.append(" W ");
                break;
            case LOG_LEVEL_ERROR:
                buf.append(" E ");
                break;
            // case : buf.append(" F "); break;
            default:
                buf.append("   ");
        }

        // Append the name of the log instance if so configured
        buf.append(name);
        buf.append(' ');

        // pad to 20 chars
        buf.append(" ".repeat(Math.max(0, 20 - (name.length() + 1))));

        // Append the message
        buf.append(LogUtil.escape(message));

        // Append stack trace if not null
        if (t != null) {
            buf.append(System.lineSeparator());

            java.io.StringWriter sw = new java.io.StringWriter(1024);
            java.io.PrintWriter pw = new java.io.PrintWriter(sw);
            t.printStackTrace(pw);
            pw.close();
            buf.append(LogUtil.escape(sw.toString()));
        }

        buf.append(System.lineSeparator());
        // Print to the appropriate destination
        return buf.toString();
    }
}