/*******************************************************************************
*   Copyright 2015 Analog Devices, Inc.
*
*   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.analog.lyric.dimple.model.core;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.jdt.annotation.NonNullByDefault;
import org.eclipse.jdt.annotation.Nullable;

import com.analog.lyric.dimple.model.variables.VariableBlock;


/**
 * Holds {@link VariableBlock}s owned by a {@link FactorGraph}.
 * <p>
 * @since 0.08
 * @author Christopher Barber
 */
final class OwnedVariableBlocks extends OwnedArray<VariableBlock>
{
	/*-------
	 * State
	 */
	
	private Map<VariableBlock,VariableBlock> _blocks = Collections.EMPTY_MAP;
	
	/*--------------
	 * Construction
	 */
	
	OwnedVariableBlocks()
	{
	}
	
	/*--------------------
	 * Collection methods
	 */

	@NonNullByDefault(false)
	@Override
	public boolean add(VariableBlock block)
	{
		if (!_blocks.containsKey(block))
		{
			_blocks.put(block, block);
			return super.add(block);
		}
		
		return false;
	}
	
	@Override
	public void clear()
	{
		_blocks.clear();
	}
	
	/*--------------------
	 * OwnedArray methods
	 */
	
	@Override
	void ensureCapacity(int newCapacity)
	{
		super.ensureCapacity(newCapacity);
		if (_blocks == Collections.EMPTY_MAP)
		{
			_blocks = new HashMap<>(newCapacity);
		}
	}
	
	@Override
	boolean removeNode(IFactorGraphChild node)
	{
		if (super.removeNode(node))
		{
			_blocks.remove(node);
			return true;
		}
		
		return false;
	}
	
	@Override
	int idTypeMask()
	{
		return Ids.VARIABLE_BLOCK_TYPE << Ids.LOCAL_ID_TYPE_OFFSET;
	}

	@Override
	VariableBlock[] resize(@Nullable VariableBlock[] array, int length)
	{
		final VariableBlock[] newArray = new VariableBlock[length];
		if (array != null)
		{
			System.arraycopy(array, 0, newArray, 0, Math.min(length, array.length));
		}
		return newArray;
	}

	/*----------------------------
	 * OwnedVariableArray methods
	 */
	
	public VariableBlock addBlock(VariableBlock block)
	{
		if (_blocks == Collections.EMPTY_MAP)
		{
			_blocks = new HashMap<>();
		}
		
		VariableBlock result = _blocks.get(block);
		
		if (result != null)
		{
			return result;
		}
		
		super.add(block);
		_blocks.put(block, block);
		return block;
	}
}
