package alice.topology.manager.keeparive;

import java.util.LinkedList;

public class ListManager {
	private LinkedList<TaskInfo> list = new LinkedList<TaskInfo>();

	public LinkedList<TaskInfo> getTaskList() {
		return list;
	}

	public void addTask(TaskInfo newInfo) {
		TaskExecuter exec = TaskExecuter.getInstance();
		TaskInfo nowTask = exec.getNowTask();
		if (nowTask == null) { // active task is nothing
			add(newInfo);
		} else {
			long remainingTime = exec.getRemainingTime();
			if (remainingTime > newInfo.getSleepTime()) {
				// active task is longer than newTask.
				TaskInfo task = nowTask.clone();
				task.setSleepTime(remainingTime);
				list.addFirst(task);
				add(newInfo);
				exec.ignore();
			} else {
				// newTask is longer than active task.
				newInfo.setSleepTime(newInfo.getSleepTime() - remainingTime);
				add(newInfo);
			}
		}
		show();
	}

	private void add(TaskInfo newInfo){
		int cnt = 0;
		for (TaskInfo info : list){
			if (info.getSleepTime() < newInfo.getSleepTime()){
				newInfo.setSleepTime(newInfo.getSleepTime() - info.getSleepTime());	
			} else if (info.getSleepTime() == newInfo.getSleepTime()){
				// newInfo.getSleepTime() - info.getSleepTime() must be Zero
				newInfo.setSleepTime(0);
				cnt++;
				break;
			} else if (info.getSleepTime() > newInfo.getSleepTime()){
				info.setSleepTime(info.getSleepTime() - newInfo.getSleepTime());
				break;
			}
			cnt++;
		}
		list.add(cnt, newInfo);
	}
	
	public boolean deleteTask(TaskInfo task){
		boolean matchFlag = false;
		int cnt = 0;
		for (TaskInfo t: list){
			if (t.getType().equals(task.getType())){
				matchFlag = true;
				if (cnt+1 < list.size() ){ // next task exists.
					TaskInfo next = list.get(cnt+1);
					next.setSleepTime(next.getSleepTime()+task.getSleepTime());
				}
				list.remove(cnt);
				break;
			} else {
				cnt++;
			}
		}	
		return matchFlag;
	}
	
	public void show(){
		if (TaskExecuter.getInstance().getNowTask()!=null){
			System.out.print("NOW | ");
			System.out.print(TaskExecuter.getInstance().getNowTask().getSleepTime());
			System.out.print(" | ");
		}
		for (TaskInfo info : list){
			System.out.print(info.getSleepTime());
			System.out.print(" | ");
		}
		System.out.println();
	}
}