package org.onap.msb.apiroute.health;

import java.text.SimpleDateFormat;

import org.onap.msb.apiroute.wrapper.util.JedisUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import redis.clients.jedis.Jedis;

import com.codahale.metrics.health.HealthCheck;

public class RedisHealthCheck extends HealthCheck implements Runnable {
	private static final Logger LOGGER = LoggerFactory
			.getLogger(RedisHealthCheck.class);

	public static boolean writeCheckFlag = true;
	private static Result result = Result.healthy();
	
	private static int failedLoopCheckNum = 12;
	private static int failedTimer = 5 * 1000;

	private static int normalTimer = 20 * 1000;

	public static Result getResult() {
		return result;
	}

	@Override
	protected Result check() {

		// check write
		if (writeCheckFlag) {
			Result writeCheckResult = checkWrite();
			if (writeCheckResult.isHealthy()) {
				writeCheckFlag = false;
			}

			// write failed
			if (!writeCheckResult.isHealthy()) {
				return writeCheckResult;
			}
		}
		
		// check read
		Result readCheckResult = checkRead();

		// read failed
		if (!readCheckResult.isHealthy()) {
			return readCheckResult;
		}

		return Result.healthy();
	}

	private Result checkRead() {
		Jedis jedisHandle = null;

		Result healthRst = Result.healthy();
		try {

			jedisHandle = JedisUtil.borrowJedisInstance();
			jedisHandle.get("healthchek:checktime");

		} catch (Exception e) {
			LOGGER.warn("RedisHealthCheck exception", e);
			healthRst = Result.unhealthy(e);
		} finally {
			JedisUtil.returnJedisInstance(jedisHandle);
		}

		return healthRst;
	}

	private Result checkWrite() {
		Jedis jedisHandle = null;

		Result healthRst = Result.healthy();
		try {

			long currentTime = System.currentTimeMillis();
			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
			String date = sdf.format(currentTime);

			jedisHandle = JedisUtil.borrowJedisInstance();
			String statusCode = jedisHandle.set("healthchek:checktime", date);

			if (statusCode != null && statusCode.equals("OK")) {
				healthRst = Result.healthy("check redis:" + statusCode);
			} else {
				healthRst = Result.unhealthy("check redis:" + statusCode);
			}

		} catch (Exception e) {
			LOGGER.warn("RedisHealthCheck exception", e);
			healthRst = Result.unhealthy(e);
		} finally {
			JedisUtil.returnJedisInstance(jedisHandle);
		}

		return healthRst;
	}

	@Override
	public void run() {
		// TODO Auto-generated method stub
		while (true) {

			if (LOGGER.isDebugEnabled()) {
				LOGGER.debug("redis check starttime:"
						+ System.currentTimeMillis());
			}

			result = checkWithPolicy();

			if (LOGGER.isDebugEnabled()) {
				LOGGER.debug("redis check result:" + result.isHealthy()
						+ " message:" + result.getMessage());
				
				LOGGER.debug("redis check endtime:"
						+ System.currentTimeMillis());
			}

			try {
				Thread.sleep(normalTimer);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				LOGGER.warn("loop check redis,thread sleep excepiton", e);
			}
		}
	}
	
	private Result checkWithPolicy() {
		int failedNum = 0;
		Result temp = Result.healthy();

		do {
			// check again
			temp = check();

			// healthy break;
			if (temp.isHealthy()) {
				break;
			}

			// unhealthy go on
			failedNum++;
			
			try {
				Thread.sleep(failedTimer);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				LOGGER.warn("loop check redis,thread sleep excepiton", e);
			}
			
		} while (failedNum <= failedLoopCheckNum);

		return temp;
	}
}