package net.minecraft.world.level.chunk.status;

import com.google.common.collect.ImmutableList;
import java.util.ArrayList;
import java.util.List;
import java.util.function.UnaryOperator;
import net.minecraft.core.BlockPos;
import net.minecraft.core.SectionPos;

public record ChunkPyramid(ImmutableList<ChunkStep> steps) {
	public static final ChunkPyramid GENERATION_PYRAMID = new ChunkPyramid.Builder()
		.step(ChunkStatus.EMPTY, s -> s)
		.step(ChunkStatus.STRUCTURE_STARTS, s -> s.setTask(ChunkStatusTasks::generateStructureStarts))
		.step(ChunkStatus.STRUCTURE_REFERENCES, s -> s.addRequirement(ChunkStatus.STRUCTURE_STARTS, 8).setTask(ChunkStatusTasks::generateStructureReferences))
		.step(ChunkStatus.BIOMES, s -> s.addRequirement(ChunkStatus.STRUCTURE_STARTS, 8).setTask(ChunkStatusTasks::generateBiomes))
		.step(
			ChunkStatus.NOISE,
			s -> s.addRequirement(ChunkStatus.STRUCTURE_STARTS, 8)
				.addRequirement(ChunkStatus.BIOMES, 1)
				.blockStateWriteRadius(0)
				.setTask(ChunkStatusTasks::generateNoise)
		)
		.step(
			ChunkStatus.SURFACE,
			s -> s.addRequirement(ChunkStatus.STRUCTURE_STARTS, 8)
				.addRequirement(ChunkStatus.BIOMES, 1)
				.blockStateWriteRadius(0)
				.setTask(ChunkStatusTasks::generateSurface)
		)
		.step(ChunkStatus.CARVERS, s -> s.addRequirement(ChunkStatus.STRUCTURE_STARTS, 8).blockStateWriteRadius(0).setTask(ChunkStatusTasks::generateCarvers))
		.step(
			ChunkStatus.FEATURES,
			s -> s.addRequirement(ChunkStatus.STRUCTURE_STARTS, 8)
				.addRequirement(ChunkStatus.CARVERS, 1)
				.blockStateWriteRadius(1)
				.setTask(ChunkStatusTasks::generateFeatures)
		)
		.step(ChunkStatus.INITIALIZE_LIGHT, s -> s.setTask(ChunkStatusTasks::initializeLight))
		.step(ChunkStatus.LIGHT, s -> s.addRequirement(ChunkStatus.INITIALIZE_LIGHT, 1).setTask(ChunkStatusTasks::light))
		.step(ChunkStatus.SPAWN, s -> s.addRequirement(ChunkStatus.BIOMES, 1).setTask(ChunkStatusTasks::generateSpawn))
		.step(ChunkStatus.FULL, s -> s.setTask(ChunkStatusTasks::full))
		.build();
	public static final ChunkPyramid LOADING_PYRAMID = new ChunkPyramid.Builder()
		.step(ChunkStatus.EMPTY, s -> s)
		.step(ChunkStatus.STRUCTURE_STARTS, s -> s.setTask(ChunkStatusTasks::loadStructureStarts))
		.step(ChunkStatus.STRUCTURE_REFERENCES, s -> s)
		.step(ChunkStatus.BIOMES, s -> s)
		.step(ChunkStatus.NOISE, s -> s)
		.step(ChunkStatus.SURFACE, s -> s)
		.step(ChunkStatus.CARVERS, s -> s)
		.step(ChunkStatus.FEATURES, s -> s)
		.step(ChunkStatus.INITIALIZE_LIGHT, s -> s.setTask(ChunkStatusTasks::initializeLight))
		.step(ChunkStatus.LIGHT, s -> s.addRequirement(ChunkStatus.INITIALIZE_LIGHT, 1).setTask(ChunkStatusTasks::light))
		.step(ChunkStatus.SPAWN, s -> s)
		.step(ChunkStatus.FULL, s -> s.setTask(ChunkStatusTasks::full))
		.build();
	private static final int SAFETY_MARGIN_CHUNKS = (32 + GENERATION_PYRAMID.getStepTo(ChunkStatus.FULL).accumulatedDependencies().size() + 1) * 2;
	public static final int MAX_CHUNK_COORDINATE_VALUE = SectionPos.blockToSectionCoord(BlockPos.MAX_HORIZONTAL_COORDINATE) - SAFETY_MARGIN_CHUNKS;

	public ChunkStep getStepTo(final ChunkStatus status) {
		return (ChunkStep)this.steps.get(status.getIndex());
	}

	public static class Builder {
		private final List<ChunkStep> steps = new ArrayList();

		public ChunkPyramid build() {
			return new ChunkPyramid(ImmutableList.copyOf(this.steps));
		}

		public ChunkPyramid.Builder step(final ChunkStatus status, final UnaryOperator<ChunkStep.Builder> operator) {
			ChunkStep.Builder stepBuilder;
			if (this.steps.isEmpty()) {
				stepBuilder = new ChunkStep.Builder(status);
			} else {
				stepBuilder = new ChunkStep.Builder(status, (ChunkStep)this.steps.getLast());
			}

			this.steps.add(((ChunkStep.Builder)operator.apply(stepBuilder)).build());
			return this;
		}
	}
}