package net.minecraft.world.level.chunk;

import java.util.List;
import java.util.function.Predicate;
import net.minecraft.core.IdMap;
import net.minecraft.network.FriendlyByteBuf;
import net.minecraft.network.VarInt;
import org.apache.commons.lang3.Validate;

public class LinearPalette<T> implements Palette<T> {
	private final IdMap<T> registry;
	private final T[] values;
	private final PaletteResize<T> resizeHandler;
	private final int bits;
	private int size;

	private LinearPalette(IdMap<T> registry, int bits, PaletteResize<T> resizeHandler, List<T> values) {
		this.registry = registry;
		this.values = (T[])(new Object[1 << bits]);
		this.bits = bits;
		this.resizeHandler = resizeHandler;
		Validate.isTrue(values.size() <= this.values.length, "Can't initialize LinearPalette of size %d with %d entries", this.values.length, values.size());

		for (int i = 0; i < values.size(); i++) {
			this.values[i] = (T)values.get(i);
		}

		this.size = values.size();
	}

	private LinearPalette(IdMap<T> registry, T[] values, PaletteResize<T> resizeHandler, int bits, int size) {
		this.registry = registry;
		this.values = values;
		this.resizeHandler = resizeHandler;
		this.bits = bits;
		this.size = size;
	}

	public static <A> Palette<A> create(int bits, IdMap<A> registry, PaletteResize<A> resizeHandler, List<A> values) {
		return new LinearPalette<>(registry, bits, resizeHandler, values);
	}

	@Override
	public int idFor(T state) {
		for (int i = 0; i < this.size; i++) {
			if (this.values[i] == state) {
				return i;
			}
		}

		int ix = this.size;
		if (ix < this.values.length) {
			this.values[ix] = state;
			this.size++;
			return ix;
		} else {
			return this.resizeHandler.onResize(this.bits + 1, state);
		}
	}

	@Override
	public boolean maybeHas(Predicate<T> filter) {
		for (int i = 0; i < this.size; i++) {
			if (filter.test(this.values[i])) {
				return true;
			}
		}

		return false;
	}

	@Override
	public T valueFor(int id) {
		if (id >= 0 && id < this.size) {
			return this.values[id];
		} else {
			throw new MissingPaletteEntryException(id);
		}
	}

	@Override
	public void read(FriendlyByteBuf buffer) {
		this.size = buffer.readVarInt();

		for (int i = 0; i < this.size; i++) {
			this.values[i] = this.registry.byIdOrThrow(buffer.readVarInt());
		}
	}

	@Override
	public void write(FriendlyByteBuf buffer) {
		buffer.writeVarInt(this.size);

		for (int i = 0; i < this.size; i++) {
			buffer.writeVarInt(this.registry.getId(this.values[i]));
		}
	}

	@Override
	public int getSerializedSize() {
		int i = VarInt.getByteSize(this.getSize());

		for (int j = 0; j < this.getSize(); j++) {
			i += VarInt.getByteSize(this.registry.getId(this.values[j]));
		}

		return i;
	}

	@Override
	public int getSize() {
		return this.size;
	}

	@Override
	public Palette<T> copy(PaletteResize<T> resizeHandler) {
		return new LinearPalette<>(this.registry, (T[])((Object[])this.values.clone()), resizeHandler, this.bits, this.size);
	}
}