/*
 * 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.management.internal.cli.commands;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.Objects;
import java.util.Set;
import java.util.TreeSet;
import java.util.stream.Collectors;

import org.springframework.shell.standard.ShellMethod;
import org.springframework.shell.standard.ShellOption;

import org.apache.geode.annotations.Immutable;
import org.apache.geode.cache.execute.ResultCollector;
import org.apache.geode.distributed.DistributedMember;
import org.apache.geode.management.cli.CliMetaData;
import org.apache.geode.management.cli.GfshCommand;
import org.apache.geode.management.internal.cli.domain.RegionInformation;
import org.apache.geode.management.internal.cli.functions.GetRegionsFunction;
import org.apache.geode.management.internal.cli.result.model.ResultModel;
import org.apache.geode.management.internal.cli.result.model.TabularResultModel;
import org.apache.geode.management.internal.i18n.CliStrings;
import org.apache.geode.management.internal.security.ResourceOperation;
import org.apache.geode.management.internal.util.ManagementUtils;
import org.apache.geode.security.ResourcePermission;

public class ListRegionCommand extends GfshCommand {
  @Immutable
  private static final GetRegionsFunction getRegionsFunction = new GetRegionsFunction();

  @ShellMethod(value = CliStrings.LIST_REGION__HELP, key = {CliStrings.LIST_REGION})
  @CliMetaData(relatedTopic = CliStrings.TOPIC_GEODE_REGION)
  @ResourceOperation(resource = ResourcePermission.Resource.CLUSTER,
      operation = ResourcePermission.Operation.READ)
  public ResultModel listRegion(
      @ShellOption(value = {CliStrings.GROUP, CliStrings.GROUPS},
          help = CliStrings.LIST_REGION__GROUP__HELP) String[] group,
      @ShellOption(value = {CliStrings.MEMBER, CliStrings.MEMBERS},
          help = CliStrings.LIST_REGION__MEMBER__HELP) String[] memberNameOrId) {
    ResultModel result = new ResultModel();

    ResultCollector<?, ?> rc;
    Set<DistributedMember> targetMembers = findMembers(group, memberNameOrId);

    if (targetMembers.isEmpty()) {
      return ResultModel.createInfo(CliStrings.NO_MEMBERS_FOUND_MESSAGE);
    }

    TabularResultModel resultData = result.addTable("regionInfo");
    rc = ManagementUtils.executeFunction(getRegionsFunction, null, targetMembers);
    ArrayList<?> resultList = (ArrayList<?>) rc.getResult();

    if (resultList != null) {
      // Gather all RegionInformation into a flat set.
      Set<RegionInformation> regionInfoSet =
          new LinkedHashSet<>(resultList.stream().filter(Objects::nonNull)
              .filter(Object[].class::isInstance).map(Object[].class::cast).flatMap(Arrays::stream)
              .filter(RegionInformation.class::isInstance).map(RegionInformation.class::cast)
              .collect(Collectors.toSet()));

      Set<String> regionNames = new TreeSet<>();

      for (RegionInformation regionInfo : regionInfoSet) {
        regionNames.add(regionInfo.getName());
        Set<String> subRegionNames = regionInfo.getSubRegionNames();

        regionNames.addAll(subRegionNames);
      }

      if (regionNames.isEmpty()) {
        return ResultModel.createInfo(CliStrings.LIST_REGION__MSG__NOT_FOUND);
      }

      for (String regionName : regionNames) {
        resultData.accumulate("List of regions", regionName);
      }
    }

    return result;
  }
}
