/*
 * Copyright (C) 2020 Nan1t
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package ru.nanit.limbo.connection.pipeline;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
import ru.nanit.limbo.protocol.ByteMessage;

@ChannelHandler.Sharable
public class VarIntLengthEncoder extends MessageToByteEncoder<ByteBuf> {

    @Override
    protected void encode(ChannelHandlerContext ctx, ByteBuf buf, ByteBuf out) {
        ByteMessage msg = new ByteMessage(out);
        msg.writeVarInt(buf.readableBytes());
        msg.writeBytes(buf);
    }

    @Override
    protected ByteBuf allocateBuffer(ChannelHandlerContext ctx, ByteBuf msg, boolean preferDirect) {
        int anticipatedRequiredCapacity = 5 + msg.readableBytes();
        return ctx.alloc().heapBuffer(anticipatedRequiredCapacity);
    }
}