/**
 * 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 backtype.storm.scheduler.multitenant;

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

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

import backtype.storm.Config;
import backtype.storm.scheduler.Cluster;
import backtype.storm.scheduler.IScheduler;
import backtype.storm.scheduler.Topologies;
import backtype.storm.scheduler.TopologyDetails;
import backtype.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<String, Number>();
        } else {
            ret = new HashMap<String, Number>(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<String, IsolatedPool>();
        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 = (String) td.getConf().get(Config.TOPOLOGY_SUBMITTER_USER);
            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...");
    }
}