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 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);
			setKey();
			return;
		}
		nowTask = list.getTaskList().poll();
		ods.update("_WAITINGLIST", list);
		if (skipFlag){
			nowTask.setSleepTime(nowTask.getSleepTime() + remainingTime);
		}
		startTime = System.currentTimeMillis();
		if (nowTask.getSleepTime()!=0){
			try {
				this.wait(nowTask.getSleepTime());
			} catch (InterruptedException e){}
		}
		if (!skipFlag){
			if (nowTask.getType() == TaskType.PING){
				ods.ping(nowTask.getManagerKey(), nowTask.getReturnKey());
				TaskInfo task = new TaskInfo(TaskType.CLOSE);
				task.setInfo(nowTask.getManagerKey(), 60 * 1000);
				ods.put("_TASKINFO", task);
				new RespondPing(nowTask.getReturnKey());
			} else {
				// no response from the Remote DataSegment. So close this connection.
				DataSegment.get(nowTask.getManagerKey()).close();
			}		
		}
		nowTask = null;
		setKey();
	}
	
	public synchronized void skip(){
		skipFlag = true;
		remainingTime = nowTask.getSleepTime() - (System.currentTimeMillis() - startTime);
		nowTask = null;
		notify();
	}

	public TaskInfo getNowTask(){
		return nowTask;
	}

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

}