package alice.topology.manager.keeparive;

import alice.codesegment.CodeSegment;
import alice.datasegment.CommandType;
import alice.datasegment.DataSegment;
import alice.datasegment.Receiver;

public class TaskExecuter extends CodeSegment {
	private Receiver info = ids.create(CommandType.TAKE);
	private TaskInfo nowTask;
	private boolean sleepFlag = false;
	private boolean skipFlag = false;
	private long startTime = 0;
	private long remainingTime = 0; 
	private static TaskExecuter instance = new TaskExecuter();

	private TaskExecuter() {}
	public static TaskExecuter getInstance() {
		return instance;
	}

	public void setKey() {
		ids.init();
		info.setKey("_WAITINGLIST");
	}

	@Override
	public synchronized void run()  {
		ListManager list = info.asClass(ListManager.class);
		if (list.getTaskList().size() == 0){
			remainingTime = 0;
			ods.update("_WAITINGLIST", list);
		} else {
			nowTask = list.getTaskList().poll();
			ods.update("_WAITINGLIST", list);
			
			if (skipFlag) {
				skipFlag = false;
				nowTask.setSleepTime(remainingTime + nowTask.getSleepTime());
				remainingTime = 0;
			}
			
			startTime = System.currentTimeMillis();
			System.out.println(nowTask.getSleepTime()+" "+nowTask.getType());
			if (nowTask.getSleepTime() != 0){
				sleepFlag = true;
				try {
					wait(nowTask.getSleepTime());
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
				sleepFlag = false;
			}
			
			if (!skipFlag){
				// ping or close
				if (nowTask.getType() == TaskType.PING) {
					ods.ping(nowTask.getManagerKey(), nowTask.getReturnKey());
					TaskInfo task = new TaskInfo(TaskType.CLOSE);
					task.setInfo(nowTask.getManagerKey(), 10 * 1000);
					ods.put("_TASKINFO", task);
					new RespondPing(nowTask.getReturnKey());
				} else if (nowTask.getType() == TaskType.CLOSE) {
					// no response from the Remote DataSegment. So close this connection.
					System.out.println("SHOTDOWN");
					DataSegment.get(nowTask.getManagerKey()).close();
				}
			}
			nowTask = null;
			startTime = 0;
		}
		setKey();
	}
	
	public synchronized void skip() {
		if (sleepFlag){
			skipFlag = true;
			if (startTime == 0){
				remainingTime = nowTask.getSleepTime();
			} else {
				remainingTime = nowTask.getSleepTime() - (System.currentTimeMillis() - startTime);
			}
			nowTask = null;			
			notify();
		}
	}

	public synchronized void ignore() {
		if (sleepFlag){
			skipFlag = true;
			remainingTime = 0;
			nowTask = null;
			notify();			
		}
	}

	public synchronized TaskInfo getNowTask() {
		return nowTask;
	}

	// only use in ListManagerTest
	public synchronized void setNowTask(TaskInfo info) {
		nowTask = info;
	}

	public synchronized long getRemainingTime() {
		if (sleepFlag) {
			if (startTime !=0) {
				return nowTask.getSleepTime() - (System.currentTimeMillis() - startTime);
			} else {
				return nowTask.getSleepTime();
			}
		} else {
			return remainingTime;
		}
	}

	public boolean compareNowTask(TaskInfo task) {
		if (nowTask != null){
			if (nowTask.getType().equals(task.getType())
					&& nowTask.getManagerKey().equals(task.getManagerKey())){
				return true;
			} 
		}
		return false;
	}

}