package net.minecraft.gametest.framework;

import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Optional;
import java.util.stream.Stream;
import net.minecraft.commands.arguments.blocks.BlockInput;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Vec3i;
import net.minecraft.core.registries.Registries;
import net.minecraft.resources.ResourceKey;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.Mirror;
import net.minecraft.world.level.block.Rotation;
import net.minecraft.world.level.block.entity.BlockEntity;
import net.minecraft.world.level.block.entity.BlockEntityType;
import net.minecraft.world.level.block.entity.TestInstanceBlockEntity;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.levelgen.Heightmap;
import net.minecraft.world.level.levelgen.structure.BoundingBox;
import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplate;
import net.minecraft.world.phys.AABB;
import net.minecraft.world.phys.Vec3;

public class StructureUtils {
	public static final int DEFAULT_Y_SEARCH_RADIUS = 10;
	public static final String DEFAULT_TEST_STRUCTURES_DIR = "Minecraft.Server/src/test/convertables/data";
	public static Path testStructuresDir = Paths.get("Minecraft.Server/src/test/convertables/data");

	public static Rotation getRotationForRotationSteps(int rotationSteps) {
		switch (rotationSteps) {
			case 0:
				return Rotation.NONE;
			case 1:
				return Rotation.CLOCKWISE_90;
			case 2:
				return Rotation.CLOCKWISE_180;
			case 3:
				return Rotation.COUNTERCLOCKWISE_90;
			default:
				throw new IllegalArgumentException("rotationSteps must be a value from 0-3. Got value " + rotationSteps);
		}
	}

	public static int getRotationStepsForRotation(Rotation rotation) {
		switch (rotation) {
			case NONE:
				return 0;
			case CLOCKWISE_90:
				return 1;
			case CLOCKWISE_180:
				return 2;
			case COUNTERCLOCKWISE_90:
				return 3;
			default:
				throw new IllegalArgumentException("Unknown rotation value, don't know how many steps it represents: " + rotation);
		}
	}

	public static TestInstanceBlockEntity createNewEmptyTest(ResourceLocation id, BlockPos pos, Vec3i size, Rotation rotation, ServerLevel level) {
		BoundingBox boundingBox = getStructureBoundingBox(TestInstanceBlockEntity.getStructurePos(pos), size, rotation);
		clearSpaceForStructure(boundingBox, level);
		level.setBlockAndUpdate(pos, Blocks.TEST_INSTANCE_BLOCK.defaultBlockState());
		TestInstanceBlockEntity testInstanceBlockEntity = (TestInstanceBlockEntity)level.getBlockEntity(pos);
		ResourceKey<GameTestInstance> resourceKey = ResourceKey.create(Registries.TEST_INSTANCE, id);
		testInstanceBlockEntity.set(
			new TestInstanceBlockEntity.Data(Optional.of(resourceKey), size, rotation, false, TestInstanceBlockEntity.Status.CLEARED, Optional.empty())
		);
		return testInstanceBlockEntity;
	}

	public static void clearSpaceForStructure(BoundingBox boundingBox, ServerLevel level) {
		int i = boundingBox.minY() - 1;
		BoundingBox boundingBox2 = new BoundingBox(
			boundingBox.minX() - 2, boundingBox.minY() - 3, boundingBox.minZ() - 3, boundingBox.maxX() + 3, boundingBox.maxY() + 20, boundingBox.maxZ() + 3
		);
		BlockPos.betweenClosedStream(boundingBox2).forEach(blockPos -> clearBlock(i, blockPos, level));
		level.getBlockTicks().clearArea(boundingBox2);
		level.clearBlockEvents(boundingBox2);
		AABB aABB = AABB.of(boundingBox2);
		List<Entity> list = level.getEntitiesOfClass(Entity.class, aABB, entity -> !(entity instanceof Player));
		list.forEach(Entity::discard);
	}

	public static BlockPos getTransformedFarCorner(BlockPos pos, Vec3i offset, Rotation rotation) {
		BlockPos blockPos = pos.offset(offset).offset(-1, -1, -1);
		return StructureTemplate.transform(blockPos, Mirror.NONE, rotation, pos);
	}

	public static BoundingBox getStructureBoundingBox(BlockPos pos, Vec3i offset, Rotation rotation) {
		BlockPos blockPos = getTransformedFarCorner(pos, offset, rotation);
		BoundingBox boundingBox = BoundingBox.fromCorners(pos, blockPos);
		int i = Math.min(boundingBox.minX(), boundingBox.maxX());
		int j = Math.min(boundingBox.minZ(), boundingBox.maxZ());
		return boundingBox.move(pos.getX() - i, 0, pos.getZ() - j);
	}

	public static Optional<BlockPos> findTestContainingPos(BlockPos pos, int radius, ServerLevel level) {
		return findTestBlocks(pos, radius, level).filter(blockPos2 -> doesStructureContain(blockPos2, pos, level)).findFirst();
	}

	public static Optional<BlockPos> findNearestTest(BlockPos pos, int radius, ServerLevel level) {
		Comparator<BlockPos> comparator = Comparator.comparingInt(blockPos2 -> blockPos2.distManhattan(pos));
		return findTestBlocks(pos, radius, level).min(comparator);
	}

	public static Stream<BlockPos> findTestBlocks(BlockPos pos, int radius, ServerLevel level) {
		BoundingBox boundingBox = getBoundingBoxAtGround(pos, radius, level);
		return BlockPos.betweenClosedStream(boundingBox).filter(blockPos -> level.getBlockState(blockPos).is(Blocks.TEST_INSTANCE_BLOCK)).map(BlockPos::immutable);
	}

	private static BoundingBox getBoundingBoxAtGround(BlockPos pos, int radius, ServerLevel level) {
		BlockPos blockPos = BlockPos.containing(pos.getX(), level.getHeightmapPos(Heightmap.Types.WORLD_SURFACE, pos).getY(), pos.getZ());
		return new BoundingBox(blockPos).inflatedBy(radius, 10, radius);
	}

	public static Stream<BlockPos> lookedAtTestPos(BlockPos pos, Entity entity, ServerLevel level) {
		int i = 200;
		Vec3 vec3 = entity.getEyePosition();
		Vec3 vec32 = vec3.add(entity.getLookAngle().scale(200.0));
		return findTestBlocks(pos, 200, level)
			.map(blockPos -> level.getBlockEntity(blockPos, BlockEntityType.TEST_INSTANCE_BLOCK))
			.flatMap(Optional::stream)
			.filter(testInstanceBlockEntity -> testInstanceBlockEntity.getStructureBounds().clip(vec3, vec32).isPresent())
			.map(BlockEntity::getBlockPos)
			.sorted(Comparator.comparing(pos::distSqr))
			.limit(1L);
	}

	private static void clearBlock(int structureBlockY, BlockPos pos, ServerLevel serverLevel) {
		BlockState blockState;
		if (pos.getY() < structureBlockY) {
			blockState = Blocks.STONE.defaultBlockState();
		} else {
			blockState = Blocks.AIR.defaultBlockState();
		}

		BlockInput blockInput = new BlockInput(blockState, Collections.emptySet(), null);
		blockInput.place(serverLevel, pos, 818);
		serverLevel.updateNeighborsAt(pos, blockState.getBlock());
	}

	private static boolean doesStructureContain(BlockPos structureBlockPos, BlockPos posToTest, ServerLevel serverLevel) {
		return serverLevel.getBlockEntity(structureBlockPos) instanceof TestInstanceBlockEntity testInstanceBlockEntity
			? testInstanceBlockEntity.getStructureBoundingBox().isInside(posToTest)
			: false;
	}
}