/*
 * 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.geode.cache.lucene.internal.directory;

import java.io.File;
import java.util.Collection;

import org.apache.geode.cache.Region;
import org.apache.geode.cache.execute.Function;
import org.apache.geode.cache.execute.FunctionContext;
import org.apache.geode.cache.execute.FunctionException;
import org.apache.geode.cache.execute.RegionFunctionContext;
import org.apache.geode.cache.lucene.LuceneService;
import org.apache.geode.cache.lucene.LuceneServiceProvider;
import org.apache.geode.cache.lucene.internal.InternalLuceneIndex;
import org.apache.geode.cache.lucene.internal.filesystem.FileSystem;
import org.apache.geode.cache.lucene.internal.repository.IndexRepository;
import org.apache.geode.cache.lucene.internal.repository.RepositoryManager;
import org.apache.geode.internal.InternalEntity;
import org.apache.geode.internal.cache.BucketNotFoundException;
import org.apache.geode.internal.logging.LogService;

import org.apache.logging.log4j.Logger;
import org.apache.lucene.index.IndexWriter;

public class DumpDirectoryFiles implements Function, InternalEntity {
  private static final long serialVersionUID = 1L;

  private static final Logger logger = LogService.getLogger();
  public static final String ID = DumpDirectoryFiles.class.getSimpleName();

  @Override
  public void execute(FunctionContext context) {
    RegionFunctionContext ctx = (RegionFunctionContext) context;

    if (!(context.getArguments() instanceof String[])) {
      throw new IllegalArgumentException("Arguments should be a string array");
    }
    String[] args = (String[]) context.getArguments();
    if (args.length != 2) {
      throw new IllegalArgumentException("Expected 2 arguments: exportLocation, indexName");
    }


    String exportLocation = args[0];
    String indexName = args[1];

    final Region<Object, Object> region = ctx.getDataSet();
    LuceneService service = LuceneServiceProvider.get(ctx.getDataSet().getCache());
    InternalLuceneIndex index =
        (InternalLuceneIndex) service.getIndex(indexName, region.getFullPath());
    if (index == null) {
      throw new IllegalStateException(
          "Index not found for region " + region + " index " + indexName);
    }

    final RepositoryManager repoManager = index.getRepositoryManager();
    try {
      final Collection<IndexRepository> repositories = repoManager.getRepositories(ctx);
      repositories.stream().forEach(repo -> {
        final IndexWriter writer = repo.getWriter();
        RegionDirectory directory = (RegionDirectory) writer.getDirectory();
        FileSystem fs = directory.getFileSystem();

        String bucketName = index.getName() + "_" + repo.getRegion().getFullPath();
        bucketName = bucketName.replace("/", "_");
        File bucketDirectory = new File(exportLocation, bucketName);
        bucketDirectory.mkdirs();
        fs.export(bucketDirectory);
      });
      context.getResultSender().lastResult(null);
    } catch (BucketNotFoundException e) {
      throw new FunctionException(e);
    }
  }

  @Override
  public String getId() {
    return ID;
  }

  @Override
  public boolean optimizeForWrite() {
    return true;
  }
}
