package com.sibvisions.javafx;

import java.util.AbstractList;
import java.util.List;

import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.collections.ListChangeListener;
import javafx.collections.ObservableList;
import javafx.collections.Sequence;
import javafx.collections.ListChangeListener.Change;

import com.sibvisions.util.ArrayUtil;

public class DummyLoadOnDemandSequence extends AbstractList<Object>
                                       implements ObservableList<Object>
{
	private List<ListChangeListener<Object>> list = new ArrayUtil<ListChangeListener<Object>>();
	
	private Sequence<Car> sqCars;
	
	private int iLoaded = 20;
	
	public DummyLoadOnDemandSequence()
	{
		sqCars = FXCollections.sequence();
		
		for (int i = 0; i < 10000; i++)
		{
			sqCars.add(new Car("T: " + i, "N" + i));
		}
	}
	
	@Override
	public Object get(int index)
	{
		if (iLoaded -1 == index)
		{
			if (iLoaded < 10000)
			{
				final int iRow = iLoaded;
				
				iLoaded += 20;
				
				Platform.runLater(new Runnable()
				{
					@SuppressWarnings("unchecked")
					public void run()
					{
						ModelChange mchange = new ModelChange(DummyLoadOnDemandSequence.this, iRow);
						
						for (ListChangeListener lcl : list)
						{
							lcl.onChanged(mchange);
						}
					}
				});
			}
			else
			{
				iLoaded = 10000;
			}
		}
		
		if (index >= sqCars.size())
		{
			return sqCars.get(sqCars.size() - 1);
		}
		else
		{
			return sqCars.get(index);
		}
	}

	@Override
	public int size()
	{
		return iLoaded;
	}
	
	@Override
	public void addListener(ListChangeListener<Object> listener)
	{
		list.add(listener);
	}

	@Override
	public void removeListener(ListChangeListener<Object> listener)
	{
		list.remove(listener);
	}

	
	/**
	 * A dummy change event.
	 * 
	 * @author René Jahn
	 */
	private static class ModelChange extends Change<Object>
	{
		private int iRow;
		
		public ModelChange(ObservableList<Object> list, int pRow)
		{
			super(list);
			
			iRow = pRow;
		}
		
		@Override
		public int getFrom()
		{
			return iRow;
		}

		@Override
		public List<Object> getRemoved()
		{
			return null;
		}

		@Override
		public int getTo()
		{
			return iRow;
		}
		
		@Override
		public boolean wasPermutated()
		{
			// TODO Auto-generated method stub
			return false;
		}
	}

	/**
	 * A simple POJO.
	 * 
	 * @author René Jahn
	 */
	public static class Car
	{
		String type;
		String name;
		
		public Car(String pType, String pName)
		{
			type = pType;
			name = pName;
		}
	}

}