DescribeNamespaceCommand.java

/*
 * Copyright © 2015 Cask Data, Inc.
 *
 * Licensed 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 co.cask.cdap.cli.command;

import co.cask.cdap.cli.ArgumentName;
import co.cask.cdap.cli.CLIConfig;
import co.cask.cdap.cli.ElementType;
import co.cask.cdap.cli.english.Article;
import co.cask.cdap.cli.english.Fragment;
import co.cask.cdap.cli.util.AbstractCommand;
import co.cask.cdap.cli.util.RowMaker;
import co.cask.cdap.cli.util.table.Table;
import co.cask.cdap.client.NamespaceClient;
import co.cask.cdap.proto.Id;
import co.cask.cdap.proto.NamespaceMeta;
import co.cask.common.cli.Arguments;
import co.cask.common.cli.Command;
import com.google.common.collect.Lists;
import com.google.inject.Inject;

import java.io.PrintStream;
import java.util.List;

/**
 * {@link Command} to describe a namespace.
 */
public class DescribeNamespaceCommand extends AbstractCommand {

  private final NamespaceClient namespaceClient;

  @Inject
  public DescribeNamespaceCommand(CLIConfig cliConfig, NamespaceClient namespaceClient) {
    super(cliConfig);
    this.namespaceClient = namespaceClient;
  }

  @Override
  public void perform(Arguments arguments, PrintStream output) throws Exception {
    Id.Namespace namespace = Id.Namespace.from(arguments.get(ArgumentName.NAMESPACE_NAME.getName()));
    NamespaceMeta namespaceMeta = namespaceClient.get(namespace);
    Table table = Table.builder()
      .setHeader("name", "description")
      .setRows(Lists.newArrayList(namespaceMeta), new RowMaker<NamespaceMeta>() {
        @Override
        public List<?> makeRow(NamespaceMeta object) {
          return Lists.newArrayList(object.getName(), object.getDescription());
        }
      }).build();
    cliConfig.getTableRenderer().render(cliConfig, output, table);
  }

  @Override
  public String getPattern() {
    return String.format("describe namespace <%s>", ArgumentName.NAMESPACE_NAME);
  }

  @Override
  public String getDescription() {
    return String.format("Describes %s", Fragment.of(Article.A, ElementType.NAMESPACE.getName()));
  }
}