package com.profiler;

import java.io.UnsupportedEncodingException;
import java.util.Map.Entry;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.profiler.common.dto.thrift.AgentInfo;
import com.profiler.common.util.SpanUtils;
import com.profiler.context.TraceContext;
import com.profiler.sender.DataSender;
import com.profiler.sender.UdpDataSender;
import com.profiler.util.NetworkUtils;

public class Agent {

    public static final String FQCN = Agent.class.getName();

    private static final Logger logger = Logger.getLogger(Agent.class.getName());

    private volatile boolean alive = false;

    private final ServerInfo serverInfo;
    private final SystemMonitor systemMonitor;
    private DataSender dataSender;

    private final String agentId;
    private final String nodeName;
    private final String applicationName;
//    private boolean validate = true;

    private Agent() {
        this.serverInfo = new ServerInfo();
        this.systemMonitor = new SystemMonitor();

//        this.agentId = getId("hippo.agentId", "UnkonwnAgentId");
//        일단 임시로 호환성을 위해 agentid에 머신name을넣도록 하자
        String machineName = NetworkUtils.getMachineName();
        this.agentId = getId("hippo.agentId", machineName);
        this.nodeName = getId("hippo.nodeName", machineName);
        this.applicationName = getId("hippo.applicationName", "UnknownApplicationName");
    }

    private String getId(String key, String defaultValue) {
        String value = System.getProperty(key, defaultValue);
        validateId(value, key);
        return value;
    }

    private void validateId(String id, String idName) {
        try {
            byte[] bytes = id.getBytes("UTF-8");
            if (bytes.length > SpanUtils.AGENT_NAME_LIMIT) {
                logger.warning(idName + " is too long(1~24) " + agentId);
            }
//            validate = false;
            // TODO 이거 후처리를 어떻게 해야 될지. agent를 시작 시키지 않아야 될거 같은데. lifecycle이 이쪽저쪽에 퍼져 있어서 일관된 stop에 문제가 있음..
        } catch (UnsupportedEncodingException e) {
            logger.log(Level.WARNING, "invalid agentId. Cause:" + e.getMessage(), e);
        }

    }

    private static class SingletonHolder {
        public static final Agent INSTANCE = new Agent();
    }

    public static Agent getInstance() {
        return SingletonHolder.INSTANCE;
    }

    public boolean isAlive() {
        return alive;
    }

    public void setIsAlive(boolean alive) {
        this.alive = alive;
    }

    public ServerInfo getServerInfo() {
        return this.serverInfo;
    }

    public String getAgentId() {
        return agentId;
    }

    public String getApplicationName() {
        return applicationName;
    }


    /**
     * HIPPO 서버로 WAS정보를 전송한다.
     */
    // TODO: life cycle을 체크하는 방법으로 바꿀까.. DEAD, STARTING, STARTED, STOPPING,
    // STOPPED
    public void sendStartupInfo() {
        logger.info("Send startup information to HIPPO server.");

        String ip = getServerInfo().getHostip();
        String ports = "";
        for (Entry<Integer, String> entry : getServerInfo().getConnectors().entrySet()) {
            ports += " " + entry.getKey();
        }

        AgentInfo agentInfo = new AgentInfo();

        agentInfo.setHostname(ip);
        agentInfo.setPorts(ports);
        agentInfo.setAgentId(getAgentId());
        agentInfo.setApplicationName(getApplicationName());
        agentInfo.setIsAlive(true);
        agentInfo.setTimestamp(System.currentTimeMillis());

        this.dataSender.send(agentInfo);
    }

    public void start() {
        logger.info("Starting HIPPO Agent.");
        // trace context 새롭게 생성.
        this.dataSender = UdpDataSender.getInstance();
        // TraceContext의 생명주기 관리 방안이 없는지 강구.
        TraceContext traceContext = TraceContext.getTraceContext();
        traceContext.setDataSender(this.dataSender);
        systemMonitor.setDataSender(dataSender);
        systemMonitor.start();
    }

    public void stop() {
        logger.info("Stopping HIPPO Agent.");
        systemMonitor.stop();

        String ip = getServerInfo().getHostip();
        String ports = "";
        for (Entry<Integer, String> entry : getServerInfo().getConnectors().entrySet()) {
            ports += " " + entry.getKey();
        }

        AgentInfo agentInfo = new AgentInfo();

        agentInfo.setHostname(ip);
        agentInfo.setPorts(ports);
        agentInfo.setIsAlive(false);
        agentInfo.setTimestamp(System.currentTimeMillis());
        agentInfo.setAgentId(getAgentId());
        agentInfo.setApplicationName(getApplicationName());

        this.dataSender.send(agentInfo);
        // 종료 처리 필요.
        this.dataSender.stop();
    }

    public static void startAgent() {
        Agent.getInstance().start();
    }

    public static void stopAgent() {
        Agent.getInstance().stop();
    }
}