/*
 * 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.accumulo.cluster;

import static java.util.Objects.requireNonNull;

import java.io.File;
import java.io.IOException;
import java.util.Map;

import org.apache.hadoop.util.Shell.ShellCommandExecutor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Execute a command, leveraging Hadoop's {@link ShellCommandExecutor}, on a remote host. SSH
 * configuration provided by {@link RemoteShellOptions}.
 */
public class RemoteShell extends ShellCommandExecutor {
  private static final Logger log = LoggerFactory.getLogger(RemoteShell.class);

  protected RemoteShellOptions options;
  protected String hostname;

  public RemoteShell(String hostname, String[] execString, File dir, Map<String,String> env,
      long timeout, RemoteShellOptions options) {
    super(execString, dir, env, timeout);
    this.hostname = hostname;
    setRemoteShellOptions(options);
  }

  public RemoteShell(String hostname, String[] execString, File dir, Map<String,String> env,
      RemoteShellOptions options) {
    super(execString, dir, env);
    this.hostname = hostname;
    setRemoteShellOptions(options);
  }

  public RemoteShell(String hostname, String[] execString, File dir, RemoteShellOptions options) {
    super(execString, dir);
    this.hostname = hostname;
    setRemoteShellOptions(options);
  }

  public RemoteShell(String hostname, String[] execString, RemoteShellOptions options) {
    super(execString);
    this.hostname = hostname;
    setRemoteShellOptions(options);
  }

  public void setRemoteShellOptions(RemoteShellOptions options) {
    requireNonNull(options);
    this.options = options;
  }

  public RemoteShellOptions getRemoteShellOptions() {
    return options;
  }

  @Override
  public String[] getExecString() {
    String hostWithUser = hostname;
    if (!options.getUserName().isEmpty()) {
      hostWithUser = options.getUserName() + "@" + hostWithUser;
    }

    String remoteCmd = String.join(" ", super.getExecString());

    String cmd = String.format("%1$s %2$s %3$s \"%4$s\"", options.getSshCommand(),
        options.getSshOptions(), hostWithUser, remoteCmd);

    log.debug("Executing full command [{}]", cmd);

    return new String[] {"/usr/bin/env", "bash", "-c", cmd};
  }

  @Override
  public void execute() throws IOException {
    super.execute();
  }

}