/**
    *
    * 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.hadoop.hbase.zookeeper;
  
  import java.io.IOException;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.HBaseConfiguration;
  import org.apache.hadoop.hbase.HBaseInterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.zookeeper.KeeperException;
  import org.apache.zookeeper.ZooKeeperMain;
  
  /**
   * Tool for running ZookeeperMain from HBase by  reading a ZooKeeper server
   * from HBase XML configuration.
   */
  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.TOOLS)
  public class ZooKeeperMainServer {
    private static final String SERVER_ARG = "-server";
  
    public String parse(final Configuration c) {
      return ZKConfig.getZKQuorumServersString(c);
    }
  
    /**
     * ZooKeeper 3.4.6 broke being able to pass commands on command line.
     * See ZOOKEEPER-1897.  This class is a hack to restore this faclity.
     */
    private static class HACK_UNTIL_ZOOKEEPER_1897_ZooKeeperMain extends ZooKeeperMain {
      public HACK_UNTIL_ZOOKEEPER_1897_ZooKeeperMain(String[] args)
      throws IOException, InterruptedException {
        super(args);
      }
  
      /**
       * Run the command-line args passed.  Calls System.exit when done.
       * @throws KeeperException
       * @throws IOException
       * @throws InterruptedException
       */
      void runCmdLine() throws KeeperException, IOException, InterruptedException {
        processCmd(this.cl);
        System.exit(0);
      }
    }
  
    /**
     * @param args
     * @return True if argument strings have a '-server' in them.
     */
    private static boolean hasServer(final String args[]) {
      return args.length > 0 && args[0].equals(SERVER_ARG);
    }
  
    /**
     * @param args
     * @return True if command-line arguments were passed.
     */
    private static boolean hasCommandLineArguments(final String args[]) {
      if (hasServer(args)) {
        if (args.length < 2) throw new IllegalStateException("-server param but no value");
        return args.length > 2;
      }
      return args.length > 0;
    }
  
    /**
     * Run the tool.
     * @param args Command line arguments. First arg is path to zookeepers file.
     */
    public static void main(String args[]) throws Exception {
      String [] newArgs = args;
      if (!hasServer(args)) {
        // Add the zk ensemble from configuration if none passed on command-line.
        Configuration conf = HBaseConfiguration.create();
        String hostport = new ZooKeeperMainServer().parse(conf);
        if (hostport != null && hostport.length() > 0) {
          newArgs = new String[args.length + 2];
          System.arraycopy(args, 0, newArgs, 2, args.length);
          newArgs[0] = "-server";
          newArgs[1] = hostport;
       }
     }
     // If command-line arguments, run our hack so they are executed.
     if (hasCommandLineArguments(args)) {
       HACK_UNTIL_ZOOKEEPER_1897_ZooKeeperMain zkm =
         new HACK_UNTIL_ZOOKEEPER_1897_ZooKeeperMain(newArgs);
       zkm.runCmdLine();
     } else {
       ZooKeeperMain.main(newArgs);
     }
   }
 }