/*
 * 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.
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package jp.gihyo.spark.ch06

import org.apache.spark.{SparkConf, SparkContext}
import org.apache.spark.streaming.{StreamingContext, Seconds}
import org.apache.spark.streaming.dstream.InputDStream

object gihyo_6_3_reduceByKeyAndWindow_efficient {
  def main(args: Array[String]) {
    if (args.length != 3) {
      new IllegalArgumentException("Invalid arguments")
      System.exit(1)
    }
    val targetHost = args(0)
    val targetHostPort = args(1).toInt
    val checkpointDir = args(2)

    val conf = new SparkConf().setAppName("NetworkWordCount")
    val sc = new SparkContext(conf)
    val ssc = new StreamingContext(sc, Seconds(5))
    val lines = ssc.socketTextStream(targetHost, targetHostPort)
    ssc.checkpoint(checkpointDir)
    run(lines)

    ssc.start
    ssc.awaitTermination
  }

  def run(stream: InputDStream[String], windowLength: Int = 10, slideInterval: Int = 5) {
    val userList = stream.map(x => (x, 1))
      .reduceByKeyAndWindow(
        (a: Int, b: Int) => a + b,
        (a: Int, b: Int) => a - b, Seconds(windowLength), Seconds(slideInterval))
    userList.print
  }
}