package net.minecraft.network.protocol.game;

import it.unimi.dsi.fastutil.shorts.ShortIterator;
import it.unimi.dsi.fastutil.shorts.ShortSet;
import java.util.function.BiConsumer;
import net.minecraft.core.BlockPos;
import net.minecraft.core.SectionPos;
import net.minecraft.network.FriendlyByteBuf;
import net.minecraft.network.codec.StreamCodec;
import net.minecraft.network.protocol.Packet;
import net.minecraft.network.protocol.PacketType;
import net.minecraft.world.level.block.Block;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.chunk.LevelChunkSection;

public class ClientboundSectionBlocksUpdatePacket implements Packet<ClientGamePacketListener> {
	public static final StreamCodec<FriendlyByteBuf, ClientboundSectionBlocksUpdatePacket> STREAM_CODEC = Packet.codec(
		ClientboundSectionBlocksUpdatePacket::write, ClientboundSectionBlocksUpdatePacket::new
	);
	private static final int POS_IN_SECTION_BITS = 12;
	private final SectionPos sectionPos;
	private final short[] positions;
	private final BlockState[] states;

	public ClientboundSectionBlocksUpdatePacket(SectionPos sectionPos, ShortSet positions, LevelChunkSection section) {
		this.sectionPos = sectionPos;
		int i = positions.size();
		this.positions = new short[i];
		this.states = new BlockState[i];
		int j = 0;

		for (ShortIterator var6 = positions.iterator(); var6.hasNext(); j++) {
			short s = (Short)var6.next();
			this.positions[j] = s;
			this.states[j] = section.getBlockState(SectionPos.sectionRelativeX(s), SectionPos.sectionRelativeY(s), SectionPos.sectionRelativeZ(s));
		}
	}

	private ClientboundSectionBlocksUpdatePacket(FriendlyByteBuf buffer) {
		this.sectionPos = SectionPos.of(buffer.readLong());
		int i = buffer.readVarInt();
		this.positions = new short[i];
		this.states = new BlockState[i];

		for (int j = 0; j < i; j++) {
			long l = buffer.readVarLong();
			this.positions[j] = (short)(l & 4095L);
			this.states[j] = Block.BLOCK_STATE_REGISTRY.byId((int)(l >>> 12));
		}
	}

	/**
	 * Writes the raw packet data to the data stream.
	 */
	private void write(FriendlyByteBuf buffer) {
		buffer.writeLong(this.sectionPos.asLong());
		buffer.writeVarInt(this.positions.length);

		for (int i = 0; i < this.positions.length; i++) {
			buffer.writeVarLong((long)Block.getId(this.states[i]) << 12 | this.positions[i]);
		}
	}

	@Override
	public PacketType<ClientboundSectionBlocksUpdatePacket> type() {
		return GamePacketTypes.CLIENTBOUND_SECTION_BLOCKS_UPDATE;
	}

	/**
	 * Passes this Packet on to the NetHandler for processing.
	 */
	public void handle(ClientGamePacketListener handler) {
		handler.handleChunkBlocksUpdate(this);
	}

	public void runUpdates(BiConsumer<BlockPos, BlockState> consumer) {
		BlockPos.MutableBlockPos mutableBlockPos = new BlockPos.MutableBlockPos();

		for (int i = 0; i < this.positions.length; i++) {
			short s = this.positions[i];
			mutableBlockPos.set(this.sectionPos.relativeToBlockX(s), this.sectionPos.relativeToBlockY(s), this.sectionPos.relativeToBlockZ(s));
			consumer.accept(mutableBlockPos, this.states[i]);
		}
	}
}