/*
 * 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.brooklyn.entity.monitoring.monit;

import java.util.Map;

import org.apache.brooklyn.api.entity.Entity;
import org.apache.brooklyn.api.location.Location;
import org.apache.brooklyn.entity.software.base.SoftwareProcessImpl;
import org.apache.brooklyn.feed.ssh.SshFeed;
import org.apache.brooklyn.feed.ssh.SshPollConfig;
import org.apache.brooklyn.feed.ssh.SshPollValue;
import org.apache.brooklyn.location.ssh.SshMachineLocation;
import org.apache.brooklyn.util.text.Strings;
import org.apache.brooklyn.util.time.Duration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;

public class MonitNodeImpl extends SoftwareProcessImpl implements MonitNode {
    
    private static final Logger LOG = LoggerFactory.getLogger(MonitNodeImpl.class);
    
    private SshFeed feed;
    
    public MonitNodeImpl() {
    }
    
    public MonitNodeImpl(Map<?,?> flags) {
        super(flags, null);
    }
    
    public MonitNodeImpl(Map<?,?> flags, Entity parent) {
        super(flags, parent);
    }

    @Override
    public Class<? extends MonitDriver> getDriverInterface() {
        return MonitDriver.class;
    }
    
    @Override
    public MonitDriver getDriver() {
        return (MonitDriver) super.getDriver();
    }

    @Override
    protected void connectSensors() {
        super.connectSensors();
        Location machine = Iterables.get(getLocations(), 0, null);
        
        if (machine instanceof SshMachineLocation) {
            String cmd = getDriver().getStatusCmd();
            feed = SshFeed.builder()
                .entity(this)
                .period(Duration.FIVE_SECONDS)
                .machine((SshMachineLocation) machine)
                .poll(new SshPollConfig<Boolean>(SERVICE_UP)
                    .command(cmd)
                    .setOnSuccess(true)
                    .setOnFailureOrException(false))
                .poll(new SshPollConfig<String>(MONIT_TARGET_PROCESS_NAME)
                    .command(cmd)
                    .onSuccess(new Function<SshPollValue, String>() {
                        @Override
                        public String apply(SshPollValue input) {
                            String process = Strings.getFirstWordAfter(input.getStdout(), "Process");
                            return process;
                        }
                    })
                    .setOnFailureOrException(null))
                .poll(new SshPollConfig<String>(MONIT_TARGET_PROCESS_STATUS)
                    .command(cmd)
                    .onSuccess(new Function<SshPollValue, String>() {
                        @Override
                        public String apply(SshPollValue input) {
                            return Strings.trim(Strings.getRemainderOfLineAfter(input.getStdout(), "status"));
                        }
                    })
                    .setOnFailureOrException(null))
                .build();
        } else {
            LOG.warn("Location(s) {} not an ssh-machine location, so not polling for status; setting serviceUp immediately", getLocations());
            sensors().set(SERVICE_UP, true);
        }
    }
    
    @Override
    protected void disconnectSensors() {
        if (feed != null) feed.stop();
    }

    @Override
    public String getShortName() {
        return "Monit";
    }
}