/*
 * 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
 *
 *   https://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.accumulo.shell.commands;

import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;

import org.apache.accumulo.core.client.AccumuloException;
import org.apache.accumulo.core.client.AccumuloSecurityException;
import org.apache.accumulo.core.clientImpl.Namespace;
import org.apache.accumulo.shell.Shell;
import org.apache.accumulo.shell.Shell.Command;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;

import com.google.common.collect.Iterators;

public class NamespacesCommand extends Command {
  private Option disablePaginationOpt;
  private Option namespaceIdOption;

  private static final String DEFAULT_NAMESPACE_DISPLAY_NAME = "\"\"";

  @Override
  public int execute(final String fullCommand, final CommandLine cl, final Shell shellState)
      throws AccumuloException, AccumuloSecurityException, IOException {
    Map<String,String> namespaces =
        new TreeMap<>(shellState.getAccumuloClient().namespaceOperations().namespaceIdMap());

    Iterator<String> it = Iterators.transform(namespaces.entrySet().iterator(), entry -> {
      String name = entry.getKey();
      if (Namespace.DEFAULT.name().equals(name)) {
        name = DEFAULT_NAMESPACE_DISPLAY_NAME;
      }
      String id = entry.getValue();
      if (cl.hasOption(namespaceIdOption.getOpt())) {
        return String.format(TablesCommand.NAME_AND_ID_FORMAT, name, id);
      } else {
        return name;
      }
    });

    shellState.printLines(it, !cl.hasOption(disablePaginationOpt.getOpt()));
    return 0;
  }

  @Override
  public String description() {
    return "displays a list of all existing namespaces";
  }

  @Override
  public Options getOptions() {
    final Options o = new Options();
    namespaceIdOption =
        new Option("l", "list-ids", false, "display internal namespace ids along with the name");
    o.addOption(namespaceIdOption);
    disablePaginationOpt = new Option("np", "no-pagination", false, "disable pagination of output");
    o.addOption(disablePaginationOpt);
    return o;
  }

  @Override
  public int numArgs() {
    return 0;
  }
}
