package net.minecraft.world.phys.shapes;

import net.minecraft.core.BlockPos;
import net.minecraft.world.entity.vehicle.AbstractMinecart;
import net.minecraft.world.level.CollisionGetter;
import net.minecraft.world.level.block.BaseRailBlock;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.block.state.properties.RailShape;
import org.jetbrains.annotations.Nullable;

public class MinecartCollisionContext extends EntityCollisionContext {
	@Nullable
	private BlockPos ingoreBelow;
	@Nullable
	private BlockPos slopeIgnore;

	protected MinecartCollisionContext(AbstractMinecart minecart, boolean canStandOnFluid) {
		super(minecart, canStandOnFluid, false);
		this.setupContext(minecart);
	}

	private void setupContext(AbstractMinecart minecart) {
		BlockPos blockPos = minecart.getCurrentBlockPosOrRailBelow();
		BlockState blockState = minecart.level().getBlockState(blockPos);
		boolean bl = BaseRailBlock.isRail(blockState);
		if (bl) {
			this.ingoreBelow = blockPos.below();
			RailShape railShape = blockState.getValue(((BaseRailBlock)blockState.getBlock()).getShapeProperty());
			if (railShape.isSlope()) {
				this.slopeIgnore = switch (railShape) {
					case ASCENDING_EAST -> blockPos.east();
					case ASCENDING_WEST -> blockPos.west();
					case ASCENDING_NORTH -> blockPos.north();
					case ASCENDING_SOUTH -> blockPos.south();
					default -> null;
				};
			}
		}
	}

	@Override
	public VoxelShape getCollisionShape(BlockState state, CollisionGetter collisionGetter, BlockPos pos) {
		return !pos.equals(this.ingoreBelow) && !pos.equals(this.slopeIgnore) ? super.getCollisionShape(state, collisionGetter, pos) : Shapes.empty();
	}
}