/*
 * Copyright 2012 LinkedIn Corp.
 * 
 * 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 azkaban.trigger.builtin;

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

import org.apache.log4j.Logger;
import org.joda.time.DateTime;
import org.joda.time.ReadablePeriod;

import azkaban.executor.ExecutableFlow;
import azkaban.executor.ExecutableNode;
import azkaban.executor.ExecutorManagerAdapter;
import azkaban.executor.ExecutorManagerException;
import azkaban.executor.Status;
import azkaban.sla.SlaOption;
import azkaban.trigger.ConditionChecker;
import azkaban.utils.Utils;

public class SlaChecker implements ConditionChecker{

	private static final Logger logger = Logger.getLogger(SlaChecker.class);
	public static final String type = "SlaChecker";
	
	private String id;
	private SlaOption slaOption;
	private int execId;
	private long checkTime = -1;
	
	private static ExecutorManagerAdapter executorManager;
	
	public SlaChecker(String id, SlaOption slaOption, int execId) {
		this.id = id;
		this.slaOption = slaOption;
		this.execId = execId;
	}

	public static void setExecutorManager(ExecutorManagerAdapter em) {
		executorManager = em;
	}
	
	private Boolean isSlaMissed(ExecutableFlow flow) {
		String type = slaOption.getType();
		logger.info("flow is " + flow.getStatus());
		if(flow.getStartTime() < 0) {
			return Boolean.FALSE;
		}
		Status status;
		if(type.equals(SlaOption.TYPE_FLOW_FINISH)) {
			if(checkTime < flow.getStartTime()) {
				ReadablePeriod duration = Utils.parsePeriodString((String) slaOption.getInfo().get(SlaOption.INFO_DURATION));
				DateTime startTime = new DateTime(flow.getStartTime());
				DateTime nextCheckTime = startTime.plus(duration);
				this.checkTime = nextCheckTime.getMillis();
			}
			status = flow.getStatus();
			if(checkTime < DateTime.now().getMillis()) {
				return !isFlowFinished(status);
			}
		} else if(type.equals(SlaOption.TYPE_FLOW_SUCCEED)) {
			if(checkTime < flow.getStartTime()) {
				ReadablePeriod duration = Utils.parsePeriodString((String) slaOption.getInfo().get(SlaOption.INFO_DURATION));
				DateTime startTime = new DateTime(flow.getStartTime());
				DateTime nextCheckTime = startTime.plus(duration);
				this.checkTime = nextCheckTime.getMillis();
			}
			status = flow.getStatus();
			if(checkTime < DateTime.now().getMillis()) {
				return !isFlowSucceeded(status);
			} else {
				return status.equals(Status.FAILED) || status.equals(Status.KILLED);
			}
		} else if(type.equals(SlaOption.TYPE_JOB_FINISH)) {
			String jobName = (String) slaOption.getInfo().get(SlaOption.INFO_JOB_NAME); 
			ExecutableNode node = flow.getExecutableNode(jobName);
			if(node.getStartTime() < 0) {
				return Boolean.FALSE;
			}
			if(checkTime < node.getStartTime()) {
				ReadablePeriod duration = Utils.parsePeriodString((String) slaOption.getInfo().get(SlaOption.INFO_DURATION));
				DateTime startTime = new DateTime(node.getStartTime());
				DateTime nextCheckTime = startTime.plus(duration);
				this.checkTime = nextCheckTime.getMillis();
			}
			status = node.getStatus();
			if(checkTime < DateTime.now().getMillis()) {
				return !isJobFinished(status);
			}
		} else if(type.equals(SlaOption.TYPE_JOB_SUCCEED)) {
			String jobName = (String) slaOption.getInfo().get(SlaOption.INFO_JOB_NAME); 
			ExecutableNode node = flow.getExecutableNode(jobName);
			if(node.getStartTime() < 0) {
				return Boolean.FALSE;
			}
			if(checkTime < node.getStartTime()) {
				ReadablePeriod duration = Utils.parsePeriodString((String) slaOption.getInfo().get(SlaOption.INFO_DURATION));
				DateTime startTime = new DateTime(node.getStartTime());
				DateTime nextCheckTime = startTime.plus(duration);
				this.checkTime = nextCheckTime.getMillis();
			}
			status = node.getStatus();
			if(checkTime < DateTime.now().getMillis()) {
				return !isJobFinished(status);
			} else {
				return status.equals(Status.FAILED) || status.equals(Status.KILLED);
			}
		} 
		return Boolean.FALSE;
	}
	
	private Boolean isSlaGood(ExecutableFlow flow) {
		String type = slaOption.getType();
		logger.info("flow is " + flow.getStatus());
		if(flow.getStartTime() < 0) {
			return Boolean.FALSE;
		}
		Status status;
		if(type.equals(SlaOption.TYPE_FLOW_FINISH)) {
			if(checkTime < flow.getStartTime()) {
				ReadablePeriod duration = Utils.parsePeriodString((String) slaOption.getInfo().get(SlaOption.INFO_DURATION));
				DateTime startTime = new DateTime(flow.getStartTime());
				DateTime nextCheckTime = startTime.plus(duration);
				this.checkTime = nextCheckTime.getMillis();
			}
			status = flow.getStatus();
			return isFlowFinished(status);
		} else if(type.equals(SlaOption.TYPE_FLOW_SUCCEED)) {
			if(checkTime < flow.getStartTime()) {
				ReadablePeriod duration = Utils.parsePeriodString((String) slaOption.getInfo().get(SlaOption.INFO_DURATION));
				DateTime startTime = new DateTime(flow.getStartTime());
				DateTime nextCheckTime = startTime.plus(duration);
				this.checkTime = nextCheckTime.getMillis();
			}
			status = flow.getStatus();
			return isFlowSucceeded(status);
		} else if(type.equals(SlaOption.TYPE_JOB_FINISH)) {
			String jobName = (String) slaOption.getInfo().get(SlaOption.INFO_JOB_NAME); 
			ExecutableNode node = flow.getExecutableNode(jobName);
			if(node.getStartTime() < 0) {
				return Boolean.FALSE;
			}
			if(checkTime < node.getStartTime()) {
				ReadablePeriod duration = Utils.parsePeriodString((String) slaOption.getInfo().get(SlaOption.INFO_DURATION));
				DateTime startTime = new DateTime(node.getStartTime());
				DateTime nextCheckTime = startTime.plus(duration);
				this.checkTime = nextCheckTime.getMillis();
			}
			status = node.getStatus();
			return isJobFinished(status);
		} else if(type.equals(SlaOption.TYPE_JOB_SUCCEED)) {
			String jobName = (String) slaOption.getInfo().get(SlaOption.INFO_JOB_NAME); 
			ExecutableNode node = flow.getExecutableNode(jobName);
			if(node.getStartTime() < 0) {
				return Boolean.FALSE;
			}
			if(checkTime < node.getStartTime()) {
				ReadablePeriod duration = Utils.parsePeriodString((String) slaOption.getInfo().get(SlaOption.INFO_DURATION));
				DateTime startTime = new DateTime(node.getStartTime());
				DateTime nextCheckTime = startTime.plus(duration);
				this.checkTime = nextCheckTime.getMillis();
			}
			status = node.getStatus();
			return isJobSucceeded(status);
		} 
		return Boolean.FALSE;
	}
	
	// return true to trigger sla action
	@Override
	public Object eval() {
		logger.info("Checking sla for execution " + execId);
		ExecutableFlow flow;
		try {
			flow = executorManager.getExecutableFlow(execId);
		} catch (ExecutorManagerException e) {
			logger.error("Can't get executable flow.", e);
			e.printStackTrace();
			// something wrong, send out alerts
			return Boolean.TRUE;
		}
		return isSlaMissed(flow);
	}
	
	public Object isSlaFailed() {
		logger.info("Testing if sla failed for execution " + execId);
		ExecutableFlow flow;
		try {
			flow = executorManager.getExecutableFlow(execId);
		} catch (ExecutorManagerException e) {
			logger.error("Can't get executable flow.", e);
			e.printStackTrace();
			// something wrong, send out alerts
			return Boolean.TRUE;
		}
		return isSlaMissed(flow);
	}
	
	public Object isSlaPassed() {
		logger.info("Testing if sla is good for execution " + execId);
		ExecutableFlow flow;
		try {
			flow = executorManager.getExecutableFlow(execId);
		} catch (ExecutorManagerException e) {
			logger.error("Can't get executable flow.", e);
			e.printStackTrace();
			// something wrong, send out alerts
			return Boolean.TRUE;
		}
		return isSlaGood(flow);
	}

	@Override
	public Object getNum() {
		return null;
	}

	@Override
	public void reset() {
	}

	@Override
	public String getId() {
		return id;
	}

	@Override
	public String getType() {
		return type;
	}

	@Override
	public ConditionChecker fromJson(Object obj) throws Exception {
		return createFromJson(obj);
	}

	@SuppressWarnings("unchecked")
	public static SlaChecker createFromJson(Object obj) throws Exception {
		return createFromJson((HashMap<String, Object>)obj);
	}
	
	public static SlaChecker createFromJson(HashMap<String, Object> obj) throws Exception {
		Map<String, Object> jsonObj = (HashMap<String, Object>) obj;
		if(!jsonObj.get("type").equals(type)) {
			throw new Exception("Cannot create checker of " + type + " from " + jsonObj.get("type"));
		}
		String id = (String) jsonObj.get("id");
		SlaOption slaOption = SlaOption.fromObject(jsonObj.get("slaOption"));
		int execId = Integer.valueOf((String) jsonObj.get("execId"));
		return new SlaChecker(id, slaOption, execId);
	}
	
	@Override
	public Object toJson() {
		Map<String, Object> jsonObj = new HashMap<String, Object>();
		jsonObj.put("type", type);
		jsonObj.put("id", id);
		jsonObj.put("slaOption", slaOption.toObject());
		jsonObj.put("execId", String.valueOf(execId));
	
		return jsonObj;
	}

	@Override
	public void stopChecker() {
		
	}

	@Override
	public void setContext(Map<String, Object> context) {
	}

	@Override
	public long getNextCheckTime() {
		return checkTime;
	}
	
	private boolean isFlowFinished(Status status) {
		if(status.equals(Status.FAILED) || status.equals(Status.KILLED) || status.equals(Status.SUCCEEDED)) {
			return Boolean.TRUE;
		} else {
			return Boolean.FALSE;
		}
	}
	
	private boolean isFlowSucceeded(Status status) {
		return status.equals(Status.SUCCEEDED);
	}
	
	private boolean isJobFinished(Status status) {
		if(status.equals(Status.FAILED) || status.equals(Status.KILLED) || status.equals(Status.SUCCEEDED)) {
			return Boolean.TRUE;
		} else {
			return Boolean.FALSE;
		}
	}
	
	private boolean isJobSucceeded(Status status) {
		return status.equals(Status.SUCCEEDED);
	}
}
