package net.minecraft.world.entity;

import net.minecraft.core.BlockPos;
import net.minecraft.tags.FluidTags;
import net.minecraft.world.level.LevelReader;
import net.minecraft.world.level.NaturalSpawner;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.pathfinder.PathComputationType;
import org.jspecify.annotations.Nullable;

public interface SpawnPlacementTypes {
	SpawnPlacementType NO_RESTRICTIONS = (level, blockPos, type) -> true;
	SpawnPlacementType IN_WATER = (level, blockPos, type) -> {
		if (type != null && level.getWorldBorder().isWithinBounds(blockPos)) {
			BlockPos above = blockPos.above();
			return level.getFluidState(blockPos).is(FluidTags.WATER) && !level.getBlockState(above).isRedstoneConductor(level, above);
		} else {
			return false;
		}
	};
	SpawnPlacementType IN_LAVA = (level, blockPos, type) -> type != null && level.getWorldBorder().isWithinBounds(blockPos)
		? level.getFluidState(blockPos).is(FluidTags.LAVA)
		: false;
	SpawnPlacementType ON_GROUND = new SpawnPlacementType() {
		@Override
		public boolean isSpawnPositionOk(final LevelReader level, final BlockPos blockPos, @Nullable final EntityType<?> type) {
			if (type != null && level.getWorldBorder().isWithinBounds(blockPos)) {
				BlockPos above = blockPos.above();
				BlockPos below = blockPos.below();
				BlockState belowState = level.getBlockState(below);
				return !belowState.isValidSpawn(level, below, type)
					? false
					: this.isValidEmptySpawnBlock(level, blockPos, type) && this.isValidEmptySpawnBlock(level, above, type);
			} else {
				return false;
			}
		}

		private boolean isValidEmptySpawnBlock(final LevelReader level, final BlockPos blockPos, final EntityType<?> type) {
			BlockState blockState = level.getBlockState(blockPos);
			return NaturalSpawner.isValidEmptySpawnBlock(level, blockPos, blockState, blockState.getFluidState(), type);
		}

		@Override
		public BlockPos adjustSpawnPosition(final LevelReader level, final BlockPos candidate) {
			BlockPos below = candidate.below();
			return level.getBlockState(below).isPathfindable(PathComputationType.LAND) ? below : candidate;
		}
	};
}