/**
 * 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.storm.scheduler.multitenant;

import java.util.HashMap;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.storm.Config;
import org.apache.storm.scheduler.Cluster;
import org.apache.storm.scheduler.IScheduler;
import org.apache.storm.scheduler.Topologies;
import org.apache.storm.scheduler.TopologyDetails;
import org.apache.storm.utils.Utils;

public class MultitenantScheduler implements IScheduler {
  private static final Logger LOG = LoggerFactory.getLogger(MultitenantScheduler.class);
  @SuppressWarnings("rawtypes")
  private Map _conf;
  
  @Override
  public void prepare(@SuppressWarnings("rawtypes") Map conf) {
    _conf = conf;
  }
 
  private Map<String, Number> getUserConf() {
    Map<String, Number> ret = (Map<String, Number>)_conf.get(Config.MULTITENANT_SCHEDULER_USER_POOLS);
    if (ret == null) {
      ret = new HashMap<>();
    } else {
      ret = new HashMap<>(ret);
    }

    Map fromFile = Utils.findAndReadConfigFile("multitenant-scheduler.yaml", false);
    Map<String, Number> tmp = (Map<String, Number>)fromFile.get(Config.MULTITENANT_SCHEDULER_USER_POOLS);
    if (tmp != null) {
      ret.putAll(tmp);
    }
    return ret;
  }

 
  @Override
  public void schedule(Topologies topologies, Cluster cluster) {
    LOG.debug("Rerunning scheduling...");
    Map<String, Node> nodeIdToNode = Node.getAllNodesFrom(cluster);
    
    Map<String, Number> userConf = getUserConf();
    
    Map<String, IsolatedPool> userPools = new HashMap<>();
    for (Map.Entry<String, Number> entry : userConf.entrySet()) {
      userPools.put(entry.getKey(), new IsolatedPool(entry.getValue().intValue()));
    }
    DefaultPool defaultPool = new DefaultPool();
    FreePool freePool = new FreePool();
    
    freePool.init(cluster, nodeIdToNode);
    for (IsolatedPool pool : userPools.values()) {
      pool.init(cluster, nodeIdToNode);
    }
    defaultPool.init(cluster, nodeIdToNode);
    
    for (TopologyDetails td: topologies.getTopologies()) {
      String user = td.getTopologySubmitter();
      LOG.debug("Found top {} run by user {}",td.getId(), user);
      NodePool pool = userPools.get(user);
      if (pool == null || !pool.canAdd(td)) {
        pool = defaultPool;
      }
      pool.addTopology(td);
    }
    
    //Now schedule all of the topologies that need to be scheduled
    for (IsolatedPool pool : userPools.values()) {
      pool.scheduleAsNeeded(freePool, defaultPool);
    }
    defaultPool.scheduleAsNeeded(freePool);
    LOG.debug("Scheduling done...");
  }
}