package net.minecraft.network;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
import java.util.zip.Deflater;

public class CompressionEncoder extends MessageToByteEncoder<ByteBuf> {
	private final byte[] encodeBuf = new byte[8192];
	private final Deflater deflater;
	private int threshold;

	public CompressionEncoder(final int threshold) {
		this.threshold = threshold;
		this.deflater = new Deflater();
	}

	protected void encode(final ChannelHandlerContext ctx, final ByteBuf uncompressed, final ByteBuf out) {
		int uncompressedLength = uncompressed.readableBytes();
		if (uncompressedLength > 8388608) {
			throw new IllegalArgumentException("Packet too big (is " + uncompressedLength + ", should be less than 8388608)");
		} else {
			if (uncompressedLength < this.threshold) {
				VarInt.write(out, 0);
				out.writeBytes(uncompressed);
			} else {
				byte[] input = new byte[uncompressedLength];
				uncompressed.readBytes(input);
				VarInt.write(out, input.length);
				this.deflater.setInput(input, 0, uncompressedLength);
				this.deflater.finish();

				while (!this.deflater.finished()) {
					int written = this.deflater.deflate(this.encodeBuf);
					out.writeBytes(this.encodeBuf, 0, written);
				}

				this.deflater.reset();
			}
		}
	}

	public int getThreshold() {
		return this.threshold;
	}

	public void setThreshold(final int threshold) {
		this.threshold = threshold;
	}
}