/*
 * 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 com.google.common.base.Preconditions;
import com.google.common.primitives.UnsignedBytes;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import java.util.ArrayList;
import java.util.List;
import org.opendaylight.protocol.pcep.spi.EROSubobjectRegistry;
import org.opendaylight.protocol.pcep.spi.ObjectParser;
import org.opendaylight.protocol.pcep.spi.ObjectSerializer;
import org.opendaylight.protocol.pcep.spi.PCEPDeserializerException;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.explicit.route.object.ero.Subobject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class AbstractEROWithSubobjectsParser implements ObjectParser, ObjectSerializer {

    private static final Logger LOG = LoggerFactory.getLogger(AbstractEROWithSubobjectsParser.class);

    private static final int HEADER_LENGTH = 2;

    private final EROSubobjectRegistry subobjReg;

    protected AbstractEROWithSubobjectsParser(final EROSubobjectRegistry subobjReg) {
        this.subobjReg = Preconditions.checkNotNull(subobjReg);
    }

    protected List<Subobject> parseSubobjects(final ByteBuf buffer) throws PCEPDeserializerException {
        // Explicit approval of empty ERO
        Preconditions.checkArgument(buffer != null, "Array of bytes is mandatory. Can't be null.");
        final List<Subobject> subs = new ArrayList<>();
        while (buffer.isReadable()) {
            boolean loose = ((buffer.getByte(buffer.readerIndex()) & (1 << 7)) != 0) ? true : false;
            int type = (buffer.readByte() & 0xff) & ~(1 << 7);
            int length = UnsignedBytes.toInt(buffer.readByte()) - HEADER_LENGTH;
            if (length > buffer.readableBytes()) {
                throw new PCEPDeserializerException("Wrong length specified. Passed: " + length + "; Expected: <= "
                        + buffer.readableBytes());
            }
            LOG.debug("Attempt to parse subobject from bytes: {}", ByteBufUtil.hexDump(buffer));
            final Subobject sub = this.subobjReg.parseSubobject(type, buffer.slice(buffer.readerIndex(), length), loose);
            if (sub == null) {
                LOG.warn("Unknown subobject type: {}. Ignoring subobject.", type);
            } else {
                LOG.debug("Subobject was parsed. {}", sub);
                subs.add(sub);
            }
            buffer.readerIndex(buffer.readerIndex() + length);
        }
        return subs;
    }

    protected final void serializeSubobject(final List<Subobject> subobjects, final ByteBuf buffer) {
        if(subobjects != null && !subobjects.isEmpty()) {
            for (final Subobject subobject : subobjects) {
                this.subobjReg.serializeSubobject(subobject, buffer);
            }
        }
    }
}