/*
 * Copyright 2014 Open Networking Laboratory
 *
 * 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 org.onlab.onos.provider.of.flow.impl;

import static org.slf4j.LoggerFactory.getLogger;

import java.util.concurrent.TimeUnit;

import org.jboss.netty.util.HashedWheelTimer;
import org.jboss.netty.util.Timeout;
import org.jboss.netty.util.TimerTask;
import org.onlab.onos.openflow.controller.OpenFlowSwitch;
import org.onlab.onos.openflow.controller.RoleState;
import org.onlab.util.Timer;
import org.projectfloodlight.openflow.protocol.OFFlowStatsRequest;
import org.projectfloodlight.openflow.types.OFPort;
import org.projectfloodlight.openflow.types.TableId;
import org.slf4j.Logger;

public class FlowStatsCollector implements TimerTask {

    private final Logger log = getLogger(getClass());

    private final HashedWheelTimer timer = Timer.getTimer();
    private final OpenFlowSwitch sw;
    private final int refreshInterval;

    private Timeout timeout;

    private boolean stopTimer = false;;

    public FlowStatsCollector(OpenFlowSwitch sw, int refreshInterval) {
        this.sw = sw;
        this.refreshInterval = refreshInterval;
    }

    @Override
    public void run(Timeout timeout) throws Exception {
        log.trace("Collecting stats for {}", this.sw.getStringId());

        sendFlowStatistics();

        if (!this.stopTimer) {
            log.trace("Scheduling stats collection in {} seconds for {}",
                    this.refreshInterval, this.sw.getStringId());
            timeout.getTimer().newTimeout(this, refreshInterval,
                    TimeUnit.SECONDS);
        }


    }

    private void sendFlowStatistics() {
        if (log.isTraceEnabled()) {
            log.trace("sendFlowStatistics {}:{}", sw.getStringId(), sw.getRole());
        }
        if (sw.getRole() != RoleState.MASTER) {
            // Switch not master.
            return;
        }
        OFFlowStatsRequest request = sw.factory().buildFlowStatsRequest()
                .setMatch(sw.factory().matchWildcardAll())
                .setTableId(TableId.ALL)
                .setOutPort(OFPort.NO_MASK)
                .build();

        this.sw.sendMsg(request);

    }

    public void start() {

        /*
         * Initially start polling quickly. Then drop down to configured value
         */
        log.info("Starting Stats collection thread for {}",
                this.sw.getStringId());
        timeout = timer.newTimeout(this, 1, TimeUnit.SECONDS);
    }

    public void stop() {
        log.info("Stopping Stats collection thread for {}",
                this.sw.getStringId());
        this.stopTimer = true;
        timeout.cancel();
    }

}