/*
 * 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.hudi.client.transaction.lock;

import org.apache.hudi.common.config.LockConfiguration;
import org.apache.hudi.common.config.TypedProperties;
import org.apache.hudi.common.lock.LockProvider;
import org.apache.hudi.common.lock.LockState;
import org.apache.hudi.common.util.StringUtils;
import org.apache.hudi.exception.HoodieLockException;

import org.apache.hadoop.conf.Configuration;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.jetbrains.annotations.NotNull;

import java.io.Serializable;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * InProcess level lock. This {@link LockProvider} implementation is to
 * guard table from concurrent operations happening in the local JVM process.
 * <p>
 * Note: This Lock provider implementation doesn't allow lock reentrancy.
 * Attempting to reacquire the lock from the same thread will throw
 * HoodieLockException. Threads other than the current lock owner, will
 * block on lock() and return false on tryLock().
 */
public class InProcessLockProvider implements LockProvider<ReentrantReadWriteLock>, Serializable {

  private static final Logger LOG = LogManager.getLogger(InProcessLockProvider.class);
  private static final ReentrantReadWriteLock LOCK = new ReentrantReadWriteLock();
  private final long maxWaitTimeMillis;

  public InProcessLockProvider(final LockConfiguration lockConfiguration, final Configuration conf) {
    TypedProperties typedProperties = lockConfiguration.getConfig();
    maxWaitTimeMillis = typedProperties.getLong(LockConfiguration.LOCK_ACQUIRE_WAIT_TIMEOUT_MS_PROP_KEY,
        LockConfiguration.DEFAULT_ACQUIRE_LOCK_WAIT_TIMEOUT_MS);
  }

  @Override
  public void lock() {
    LOG.info(getLogMessage(LockState.ACQUIRING));
    if (LOCK.isWriteLockedByCurrentThread()) {
      throw new HoodieLockException(getLogMessage(LockState.ALREADY_ACQUIRED));
    }
    LOCK.writeLock().lock();
    LOG.info(getLogMessage(LockState.ACQUIRED));
  }

  @Override
  public boolean tryLock() {
    return tryLock(maxWaitTimeMillis, TimeUnit.MILLISECONDS);
  }

  @Override
  public boolean tryLock(long time, @NotNull TimeUnit unit) {
    LOG.info(getLogMessage(LockState.ACQUIRING));
    if (LOCK.isWriteLockedByCurrentThread()) {
      throw new HoodieLockException(getLogMessage(LockState.ALREADY_ACQUIRED));
    }

    boolean isLockAcquired;
    try {
      isLockAcquired = LOCK.writeLock().tryLock(time, unit);
    } catch (InterruptedException e) {
      throw new HoodieLockException(getLogMessage(LockState.FAILED_TO_ACQUIRE));
    }

    LOG.info(getLogMessage(isLockAcquired ? LockState.ACQUIRED : LockState.FAILED_TO_ACQUIRE));
    return isLockAcquired;
  }

  @Override
  public void unlock() {
    LOG.info(getLogMessage(LockState.RELEASING));
    try {
      if (LOCK.isWriteLockedByCurrentThread()) {
        LOCK.writeLock().unlock();
      } else {
        LOG.warn("Cannot unlock because the current thread does not hold the lock.");
      }
    } catch (Exception e) {
      throw new HoodieLockException(getLogMessage(LockState.FAILED_TO_RELEASE), e);
    }
    LOG.info(getLogMessage(LockState.RELEASED));
  }

  @Override
  public ReentrantReadWriteLock getLock() {
    return LOCK;
  }

  @Override
  public void close() {
    if (LOCK.isWriteLockedByCurrentThread()) {
      LOCK.writeLock().unlock();
    }
  }

  private String getLogMessage(LockState state) {
    return StringUtils.join("Thread ", String.valueOf(Thread.currentThread().getName()), " ",
        state.name(), " in-process lock.");
  }
}
