/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.protocol.pcep.impl.object;

import java.util.BitSet;
import java.util.List;

import org.opendaylight.protocol.pcep.spi.AbstractObjectWithTlvsParser;
import org.opendaylight.protocol.pcep.spi.ObjectUtil;
import org.opendaylight.protocol.pcep.spi.PCEPDeserializerException;
import org.opendaylight.protocol.pcep.spi.TlvHandlerRegistry;
import org.opendaylight.protocol.util.ByteArray;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.Object;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.ObjectHeader;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.RequestId;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.Tlv;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.svec.object.Svec;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.svec.object.SvecBuilder;

import com.google.common.collect.Lists;

/**
 * Parser for {@link Svec}
 */
public class PCEPSvecObjectParser extends AbstractObjectWithTlvsParser<SvecBuilder> {

	public static final int CLASS = 11;

	public static final int TYPE = 1;

	/*
	 * field lengths in bytes
	 */
	private static final int FLAGS_F_LENGTH = 3;
	private static final int REQ_LIST_ITEM_LENGTH = 4;

	/*
	 * fields offsets in bytes
	 */
	private static final int FLAGS_F_OFFSET = 1;
	private static final int REQ_ID_LIST_OFFSET = FLAGS_F_OFFSET + FLAGS_F_LENGTH;

	/*
	 * flags offsets inside flags field in bits
	 */
	private static final int S_FLAG_OFFSET = 21;
	private static final int N_FLAG_OFFSET = 22;
	private static final int L_FLAG_OFFSET = 23;

	/*
	 * min size in bytes
	 */
	private static final int MIN_SIZE = FLAGS_F_LENGTH + FLAGS_F_OFFSET;

	public PCEPSvecObjectParser(final TlvHandlerRegistry tlvReg) {
		super(tlvReg);
	}

	@Override
	public Svec parseObject(final ObjectHeader header, final byte[] bytes) throws PCEPDeserializerException {
		if (bytes == null || bytes.length == 0) {
			throw new IllegalArgumentException("Array of bytes is mandatory. Can't be null or empty.");
		}
		if (bytes.length < MIN_SIZE) {
			throw new PCEPDeserializerException("Wrong length of array of bytes. Passed: " + bytes.length + "; Expected: >=" + MIN_SIZE
					+ ".");
		}
		final BitSet flags = ByteArray.bytesToBitSet(ByteArray.subByte(bytes, FLAGS_F_OFFSET, FLAGS_F_LENGTH));
		final List<RequestId> requestIDs = Lists.newArrayList();

		for (int i = REQ_ID_LIST_OFFSET; i < bytes.length; i += REQ_LIST_ITEM_LENGTH) {
			requestIDs.add(new RequestId(ByteArray.bytesToLong(ByteArray.subByte(bytes, i, REQ_LIST_ITEM_LENGTH))));
		}
		if (requestIDs.isEmpty()) {
			throw new PCEPDeserializerException("Empty Svec Object - no request ids.");
		}
		final SvecBuilder builder = new SvecBuilder();

		builder.setIgnore(header.isIgnore());
		builder.setProcessingRule(header.isProcessingRule());

		builder.setLinkDiverse(flags.get(L_FLAG_OFFSET));
		builder.setNodeDiverse(flags.get(N_FLAG_OFFSET));
		builder.setSrlgDiverse(flags.get(S_FLAG_OFFSET));
		builder.setRequestsIds(requestIDs);
		return builder.build();
	}

	@Override
	public void addTlv(final SvecBuilder builder, final Tlv tlv) {
		// No tlvs defined
	}

	@Override
	public byte[] serializeObject(final Object object) {
		if (!(object instanceof Svec)) {
			throw new IllegalArgumentException("Wrong instance of PCEPObject. Passed " + object.getClass() + ". Needed SvecObject.");
		}

		final Svec svecObj = (Svec) object;
		final byte[] retBytes = new byte[svecObj.getRequestsIds().size() * REQ_LIST_ITEM_LENGTH + REQ_ID_LIST_OFFSET];
		final List<RequestId> requestIDs = svecObj.getRequestsIds();
		final BitSet flags = new BitSet(FLAGS_F_LENGTH * Byte.SIZE);
		flags.set(L_FLAG_OFFSET, svecObj.isLinkDiverse());
		flags.set(N_FLAG_OFFSET, svecObj.isNodeDiverse());
		flags.set(S_FLAG_OFFSET, svecObj.isSrlgDiverse());

		ByteArray.copyWhole(ByteArray.bitSetToBytes(flags, FLAGS_F_LENGTH), retBytes, FLAGS_F_OFFSET);

		for (int i = 0; i < requestIDs.size(); i++) {
			System.arraycopy(ByteArray.longToBytes(requestIDs.get(i).getValue(), REQ_LIST_ITEM_LENGTH), 0, retBytes, REQ_LIST_ITEM_LENGTH
					* i + REQ_ID_LIST_OFFSET, REQ_LIST_ITEM_LENGTH);
		}
		assert !(requestIDs.isEmpty()) : "Empty Svec Object - no request ids.";
		return ObjectUtil.formatSubobject(TYPE, CLASS, object.isProcessingRule(), object.isIgnore(), retBytes);
	}

	@Override
	public int getObjectType() {
		return TYPE;
	}

	@Override
	public int getObjectClass() {
		return CLASS;
	}
}