/*
 * 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.nemo.driver;

import org.apache.reef.driver.client.JobMessageObserver;

import java.util.concurrent.atomic.AtomicBoolean;
import java.util.logging.Handler;
import java.util.logging.LogRecord;
import java.util.logging.SimpleFormatter;

/**
 * A simple logging handler that forwards messages to REEF client.
 */
public final class RemoteClientMessageLoggingHandler extends Handler {

  private final JobMessageObserver client;
  private final SimpleFormatter formatter;
  private final AtomicBoolean closed;

  public RemoteClientMessageLoggingHandler(final JobMessageObserver client) {
    this.client = client;
    this.closed = new AtomicBoolean(false);
    this.formatter = new SimpleFormatter();
  }

  /**
   * TODO #XXX: buffer the log messages for performance.
   */
  @Override
  public void publish(final LogRecord record) {
    final StringBuilder sb = new StringBuilder();
    sb.append(formatter.format(record));

    if (!closed.get()) {
      client.sendMessageToClient(sb.toString().getBytes());
    }
  }

  @Override
  public void flush() {

  }

  @Override
  public void close() throws SecurityException {
    closed.set(true);
  }
}