/*
 * 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.cassandra.service;

import java.io.File;
import java.util.Set;

import com.google.common.collect.ImmutableSet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.db.DisallowedDirectories;
import org.apache.cassandra.db.Keyspace;
import org.apache.cassandra.io.*;
import org.apache.cassandra.io.sstable.CorruptSSTableException;
import org.apache.cassandra.utils.JVMStabilityInspector;

public class DefaultFSErrorHandler implements FSErrorHandler
{
    private static final Logger logger = LoggerFactory.getLogger(DefaultFSErrorHandler.class);

    private static final Set<Class<?>> exceptionsSkippingDataRemoval = ImmutableSet.of(OutOfMemoryError.class);

    @Override
    public void handleCorruptSSTable(CorruptSSTableException e)
    {
        if (!StorageService.instance.isDaemonSetupCompleted())
            handleStartupFSError(e);

        switch (DatabaseDescriptor.getDiskFailurePolicy())
        {
            case die:
            case stop_paranoid:
                // exception not logged here on purpose as it is already logged
                logger.error("Stopping transports as disk_failure_policy is " + DatabaseDescriptor.getDiskFailurePolicy());
                StorageService.instance.stopTransports();
                break;
        }
    }

    @Override
    public void handleFSError(FSError e)
    {
        if (!StorageService.instance.isDaemonSetupCompleted())
            handleStartupFSError(e);

        switch (DatabaseDescriptor.getDiskFailurePolicy())
        {
            case die:
            case stop_paranoid:
            case stop:
                // exception not logged here on purpose as it is already logged
                logger.error("Stopping transports as disk_failure_policy is " + DatabaseDescriptor.getDiskFailurePolicy());
                StorageService.instance.stopTransports();
                break;
            case best_effort:

                // There are a few scenarios where we know that the node will not be able to operate properly.
                // For those scenarios we want to stop the transports and let the administrators handle the problem.
                // Those scenarios are:
                // * All the disks are full
                // * All the disks for a given keyspace have been marked as unwriteable
                if (e instanceof FSDiskFullWriteError || e instanceof FSNoDiskAvailableForWriteError)
                {
                    logger.error("Stopping transports: " + e.getCause().getMessage());
                    StorageService.instance.stopTransports();
                }

                // for both read and write errors mark the path as unwritable.
                DisallowedDirectories.maybeMarkUnwritable(e.path);
                if (e instanceof FSReadError && shouldMaybeRemoveData(e))
                {
                    File directory = DisallowedDirectories.maybeMarkUnreadable(e.path);
                    if (directory != null)
                        Keyspace.removeUnreadableSSTables(directory);
                }
                break;
            case ignore:
                // already logged, so left nothing to do
                break;
            default:
                throw new IllegalStateException();
        }
    }

    private boolean shouldMaybeRemoveData(Throwable error)
    {
        for (Throwable t = error; t != null; t = t.getCause())
        {
            for (Class<?> c : exceptionsSkippingDataRemoval)
                if (c.isAssignableFrom(t.getClass()))
                    return false;
            for (Throwable s : t.getSuppressed())
                for (Class<?> c : exceptionsSkippingDataRemoval)
                    if (c.isAssignableFrom(s.getClass()))
                        return false;
        }

        return true;
    }

    private static void handleStartupFSError(Throwable t)
    {
        switch (DatabaseDescriptor.getDiskFailurePolicy())
        {
            case stop_paranoid:
            case stop:
            case die:
                logger.error("Exiting forcefully due to file system exception on startup, disk failure policy \"{}\"",
                             DatabaseDescriptor.getDiskFailurePolicy(),
                             t);
                JVMStabilityInspector.killCurrentJVM(t, true);
                break;
            default:
                break;
        }
    }
}
