/*
 * Copyright 2018 PayPal Inc.
 *
 * 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 com.paypal.gimel.common.query.guard

import java.util.concurrent.atomic.AtomicBoolean

import org.apache.spark.sql.SparkSession

class QueryGuard(spark: SparkSession) {
  private val stopped = new AtomicBoolean(true)
  private val appTimer =
    new AppTimer[QueryGuardEvent](spark)
  private val appKill = new AppKill[QueryGuardEvent](spark)
  private val queryGuardListener =
    new QueryGuardListener[QueryGuardDelayedEvent](spark)

  def start(): Unit = {
    if (stopped.compareAndSet(true, false)) {
      spark.sparkContext.addSparkListener(queryGuardListener)
      queryGuardListener.registerConsumers(Seq(appTimer))
      appTimer.registerConsumers(Seq(appKill))
      appTimer.start()
      queryGuardListener.start()
      appKill.start()
    }
  }

  def stop(): Unit = {
    if (stopped.compareAndSet(false, true)) {
      appTimer.stop()
      queryGuardListener.stop()
      appKill.stop()
    }
  }
}
