/*
 * Copyright (c) 2010-2016 Evolveum
 *
 * 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 com.evolveum.midpoint.task.quartzimpl.execution;

import com.evolveum.midpoint.task.quartzimpl.TaskManagerQuartzImpl;
import com.evolveum.midpoint.task.quartzimpl.TaskQuartzImplUtil;
import com.evolveum.midpoint.util.logging.LoggingUtils;
import com.evolveum.midpoint.util.logging.Trace;
import com.evolveum.midpoint.util.logging.TraceManager;
import org.jetbrains.annotations.NotNull;
import org.quartz.*;

import java.util.Collections;
import java.util.List;

/**
 * @author mederly
 */
public class JobStarter implements Job {

	private static final transient Trace LOGGER = TraceManager.getTrace(JobStarter.class);

	private final String REDIRECT_FLAG = "redirected";
	public static final String TASK_OID = "oid";

	private static final int WAIT_MINIMUM = 1000;
	private static final int WAIT_MAXIMUM = 3000;

	private static TaskManagerQuartzImpl taskManager;
	/*
	 * Ugly hack - this class is instantiated not by Spring but explicitly by Quartz.
	 */
	public static void setTaskManagerQuartzImpl(TaskManagerQuartzImpl tmqi) {
		taskManager = tmqi;
	}

	@Override
	public void execute(JobExecutionContext context) throws JobExecutionException {
		String oid = (String) context.getMergedJobDataMap().get(TASK_OID);
		LOGGER.trace("Requested starting Quartz job for task {}", oid);
		if (oid == null) {
			return;			// just for safety
		}

		int wait = WAIT_MINIMUM + ((int) (Math.random() * (WAIT_MAXIMUM-WAIT_MINIMUM)));
		LOGGER.trace("Waiting for {} milliseconds", wait);
		try {
			Thread.sleep(wait);
		} catch (InterruptedException e) {
			LOGGER.warn("Interrupted wait", e);
		}

		try {
			deleteRedirectTriggers(oid);
			Scheduler scheduler = taskManager.getExecutionManager().getQuartzScheduler();
			scheduler.triggerJob(TaskQuartzImplUtil.createJobKeyForTaskOid(oid),
					new JobDataMap(Collections.singletonMap(REDIRECT_FLAG, "")));
		} catch (SchedulerException e) {
			LoggingUtils.logUnexpectedException(LOGGER, "Couldn't trigger task {}", e, oid);
		}
	}

	private void deleteRedirectTriggers(@NotNull String oid) throws SchedulerException {
		LOGGER.trace("Going to remove obsolete redirect triggers");
		Scheduler scheduler = taskManager.getExecutionManager().getQuartzScheduler();
		List<? extends Trigger> existingTriggers = scheduler.getTriggersOfJob(TaskQuartzImplUtil.createJobKeyForTaskOid(oid));
		for (Trigger trigger : existingTriggers) {
			if (trigger.getJobDataMap().containsKey(REDIRECT_FLAG)) {
				LOGGER.trace("Removing obsolete redirect trigger {}", trigger);
				scheduler.unscheduleJob(trigger.getKey());
			}
		}
	}
}