/**
 * Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
 *
 * 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 com.linkedin.pinot.client;

import java.util.Arrays;
import java.util.List;
import java.util.Properties;

import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.BytesPushThroughSerializer;


/**
 * Creates connections to Pinot, given various initialization methods.
 */
public class ConnectionFactory {
  static PinotClientTransportFactory _transportFactory = new JsonAsyncHttpPinotClientTransportFactory();

  private ConnectionFactory() {
  }

  /**
   * Creates a connection to a Pinot cluster, given its Zookeeper URL
   *
   * @param zkUrl The URL to the Zookeeper cluster, must include the cluster name e.g host:port/chroot/pinot-cluster
   * @return A connection that connects to the brokers in the given Helix cluster
   */
  public static Connection fromZookeeper(String zkUrl) {
    try {
      DynamicBrokerSelector dynamicBrokerSelector = new DynamicBrokerSelector(zkUrl);
      return new Connection(dynamicBrokerSelector, _transportFactory.buildTransport());
    } catch (Exception e) {
      throw new PinotClientException(e);
    }
  }

  /**
   * Creates a connection from properties containing the connection parameters.
   *
   * @param properties The properties to use for the connection
   * @return A connection that connects to the brokers specified in the properties
   */
  public static Connection fromProperties(Properties properties) {
    return new Connection(Arrays.asList(properties.getProperty("brokerList").split(",")), _transportFactory.buildTransport());
  }

  /**
   * Creates a connection which sends queries randomly between the specified brokers.
   *
   * @param brokers The list of brokers to send queries to
   * @return A connection to the set of brokers specified
   */
  public static Connection fromHostList(String... brokers) {
    return new Connection(Arrays.asList(brokers), _transportFactory.buildTransport());
  }  
}