/*
 * 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.fluss.rpc.netty;

import org.apache.fluss.shaded.netty4.io.netty.buffer.ByteBuf;
import org.apache.fluss.shaded.netty4.io.netty.buffer.ByteBufHolder;
import org.apache.fluss.shaded.netty4.io.netty.channel.ChannelHandlerContext;
import org.apache.fluss.shaded.netty4.io.netty.handler.logging.LogLevel;
import org.apache.fluss.shaded.netty4.io.netty.handler.logging.LoggingHandler;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;

/* This file is based on source code of Apache Spark Project (https://spark.apache.org/), licensed by the Apache
 * Software Foundation (ASF) under the Apache License, Version 2.0. See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership. */

/** A Netty logger that constructs a log handler depending on the log level. */
public class NettyLogger {
    private static final Logger logger = LoggerFactory.getLogger(NettyLogger.class);

    /** A Netty LoggingHandler which does not dump the message contents. */
    private static class NoContentLoggingHandler extends LoggingHandler {

        NoContentLoggingHandler(Class<?> clazz, LogLevel level) {
            super(clazz, level);
        }

        @Override
        protected String format(ChannelHandlerContext ctx, String eventName, Object arg) {
            if (arg instanceof ByteBuf) {
                return format(ctx, eventName) + " " + ((ByteBuf) arg).readableBytes() + "B";
            } else if (arg instanceof ByteBufHolder) {
                return format(ctx, eventName)
                        + " "
                        + ((ByteBufHolder) arg).content().readableBytes()
                        + "B";
            } else if (arg instanceof InputStream) {
                int available = -1;
                try {
                    available = ((InputStream) arg).available();
                } catch (IOException ex) {
                    // Swallow, but return -1 to indicate an error happened
                }
                return format(ctx, eventName, arg) + " " + available + "B";
            } else {
                return super.format(ctx, eventName, arg);
            }
        }
    }

    private final LoggingHandler loggingHandler;

    public NettyLogger() {
        if (logger.isTraceEnabled()) {
            loggingHandler = new LoggingHandler(NettyLogger.class, LogLevel.TRACE);
        } else if (logger.isDebugEnabled()) {
            loggingHandler = new NoContentLoggingHandler(NettyLogger.class, LogLevel.DEBUG);
        } else {
            loggingHandler = null;
        }
    }

    public LoggingHandler getLoggingHandler() {
        return loggingHandler;
    }
}
